Thyroid and breast activity

Question 1

Which muscle divides the anterior and posterior triangles of the neck?

Answer 1

Sternocleidomastoid

Question 2

What are the important muscles in the anterior neck to be aware of?

Answer 2

Strap muscles (infrahyoid, sternohyoid, and omohyoid)
The sternocleidomastoid muscle; and
The longus colli muscle.

Question 3

Briefly describe the anterior triangle of the neck

Answer 3

The anterior triangle is an inverted triangle with its base above and the apex pointing downwards at the manubrium of the sternum. It can be further subdivided into smaller triangles by the crossing of digastric and omohyoid muscles.

Question 4

What are the boundaries of the anterior triangle of the neck?

Answer 4

• anterior: median line of the neck
• posterior: anterior margin of sternocleidomastoid
• base: inferior border of the mandible
  • the roof of platysma muscle and subcutaneous tissues;
  • the floor, formed by the pharynx, larynx and thyroid gland;
  • the apex which is the jugular notch; and
  • the base, which is a line from the inferior border of the mandible to the mastoid process.

Question 5

What are the subdivisions of the anterior triangle of the neck?

Answer 5

The anterior triangle is subdivided into 3 ½ triangles by the anterior and posterior bellies of digastric muscle and superior belly of omohyoid muscle. The subdivisions are as follows:

• digastric (submandibular) triangle
• muscular triangle
• carotid triangle
• submental triangle (half, only because there is only one submental triangle)

Question 6

What are the borders of the posterior triangle of the neck?

Answer 6

• the posterior border of sternocleidomastoid muscle;
• the anterior border of the trapezius muscle;
• the middle third of the clavicle, forming the base of the triangle;
• the roof, formed by cervical fascia; and
• the floor, formed by muscles and deep cervical fascia.

Question 7

What are the subdivisions of the posterior triangle?

Answer 7

The posterior triangle can then be subdivided into the occipital triangle and the supraclavicular or subclavian triangle.

Question 8

Briefly describe the contents of the posterior triangle

Answer 8

The posterior triangle contains mostly vessels and nerves that connect the neck and the upper limb. It also contains superficial and deep lymph nodes.

Question 9

Breifly describe the anterior triangle and it’s contents

Answer 9

The anterior triangle contains glandular structures (such as the thyroid and parathyroid glands) and lymphatics. The carotid triangle in particular contains the carotid vessels and associated veins and nerves.

Question 10

What is the term for the normal secretion of thyroid hormones?

Answer 10

euthryroid

Question 11

List the laboratory tests used to assess the parathyroid gland

Answer 11

Alkaline phosphatase, calcium, parathyroid hormone (PTH)

Question 12

List the laboratory tests used to assess the thyroid gland

Answer 12

Radioactive Iodine Uptake (RAIU), TSH level, t$ (thyroxine), T3 (tri-iodothyronine).

Question 13

List the laboratory tests used to assess the thyroid gland

Answer 13

Radioactive Iodine Uptake (RAIU), TSH level, T3 (thyroxine), T3 (tri-iodothyronine).

Question 14

What does Radioactive Iodine Uptake (RAIU) test?

Answer 14

Thyroid function

Question 15

What does TSH do and how does it affect T3 and T4.

Answer 15

TSH is secreted by the anterior pituitary on stimulation by TRH from the hypothalamus. TSH stimulates the release of T3 and T4 by the thyroid. T4 is secreted by the thyroid gland in response to TSH; only a small amount circulates freely in blood. T3 is the more potent thyroid hormone and is secreted in response to TSH.

Question 16

Describe the laboratory tests that would be used in a patient that presents with the following clinical features.
Draw possible conclusions as to the cause of these symptoms.
Describe the most common condition that may cause these symptoms.

Feeling hot, increased sweating, weight loss, enlargement of the thyroid gland, rapid heart rate and palpitations, anxiety and restless hyperactivity.

Answer 16

A patient with the described clinical features is presenting with common features of Graves’ disease with hyperthyroidism. Laboratory tests would be performed to identify TSH levels, T3 and T4. T3 and T4 will be elevated above normal ranges. TSH will be decreased due the feedback mechanism not requiring further TSH secretion in the presence of increased T3 and T4 circulating in the blood. RAIU could be also performed, but the other tests are more specific as hyperthyroidism does not always cause high iodine uptake.

Graves’ disease is the most common diffuse abnormality of the thyroid gland. It is an auto-immune disorder in which antibodies are produced against TSH receptors. These are called thyroid-stimulating antibodies which bind to TSH receptors and stimulate thyroid hormone secretion (other terms for this antibody you may come across are long-acting thyroid stimulator or thyroid-stimulating immunoglobulins).

Graves’ disease generally occurs in younger women, and may cause exophthalmos (protruding eyeballs), smoothly enlarged thyroid, increased appetite, weight loss, muscle wasting, diarrhoea, increased nervousness and excitability, raised blood pressure, warmth, sweatiness and amenorrhoea.

Question 17

Describe the laboratory tests that would be used in a patient that presents with the following clinical features.
Draw possible conclusions as to the cause of these symptoms.
Describe the most common condition that may cause these symptoms.
Cold intolerance, facial and extremity oedema, lethargy, weight gain, bradycardia, constipation, hair loss.

Answer 17

A patient with the described clinical features is presenting with common features of hypothyroidism. Laboratory tests would be performed to identify TSH levels, T4 and T3. TSH will be elevated above the normal range as it is further secreted due to low circulating levels of T3 and T4. This is a sensitive early marker. A RAIU test could be also performed and would show reduced iodine uptake.

Hashimoto’s thyroiditis is the most common cause, clinically presenting with reduced thyroid function and the symptoms of myxedema due to reduced metabolic rate. This is an auto-immune disease that presents more often in women than men. Occasionally the initial tests in Hashimoto’s thyroiditis may show hyperthyroid levels, but usually the patient does not present until the disease has passed through the euthyroid state into an increasing hypothyroid state.

Symptoms of this disease are as described in the case history; the thyroid gland is usually prominent and ‘rubbery’ to palpate. TSH tests can be further used to monitor the effectiveness of the thyroid hormone replacement therapy used to treat the disease. Other causes of these symptoms may be previous thyroidectomy or low iodine intake.

Question 18

Describe the laboratory tests that would be used in a patient that presents with the following clinical features.
Draw possible conclusions as to the cause of these symptoms.
Describe the most common condition that may cause these symptoms.
Prominent, irregular neck swelling, difficulty in swallowing, occasional neck pain.

Answer 18

A patient with the described clinical features is presenting with common features of multi-nodular goitre. Laboratory tests would be performed to identify RAIU, TSH levels, T3 and T4. These may all show normal levels, unless there is a dominant functional adenoma that will cause an elevation of the RAIU, T3 and T4 tests, with a reduction in the TSH levels. Usually these goitres are euthyroid in nature.

Multinodular goitre may present as a generalised enlargement of the thyroid gland or it may have irregular margins with variable sized, palpable nodules. Often one nodule may rapidly increase in size due to internal haemorrhage into the nodule. This can cause pain and increase the patient’s symptoms of dysphagia.

Question 19

Describe the laboratory tests that would be used in a patient that presents with the following clinical features.
Draw possible conclusions as to the cause of these symptoms.
Describe the most common condition that may cause these symptoms.
History of renal calculi, unilateral (mild) neck swelling.

Answer 19

A patient with the described clinical features is presenting with common features of parathyroid adenoma. Laboratory tests that would be performed will assess serum calcium and parathormone levels. Both of these will be elevated. This effectively rules out a malignant cause of the palpable mass as you would expect the parathormone levels to be suppressed with malignancy.

Parathyroid adenomas are often small, but may enlarge to be palpable. Careful assessment to look for additional enlarged glands is important, so as to rule out parathyroid hyperplasia.

Question 20

briefly describe thyroid embryological development.

Answer 20

The thyroid gland is the first endocrine gland to form in the embryo. It appears during the fourth embryonic week as a median endodermal thickening in the floor of the primitive pharynx which forms a downgrowth known as the Thyroid Diverticulum. The developing thyroid descends through the tissues of the neck at the end of a slender thyroglossal duct, which breaks down by the end of the fifth embryonic week. The isolated thyroid gland continues to descend, reaching its final resting place just inferior to the cricoid cartilage by the seventh week. The only remnant, normally, of the thyroglossal duct is the foramen caecum of the tongue.

Question 21

describe which transducer(s) you would use to perform the ultrasound scan:
1.(a) thin patient, small thyroid lobes;

Answer 21

A high-frequency (10 MHz or higher) linear probe is preferred for head and neck ultrasound, because it provides optimal resolution. If the long axis of the thyroid lobes can be fully imaged by that transducer, then no other will be required. If not, then a high frequency convex linear array may be required to adequately assess the true length of the lobes, otherwise dual imaging can be utilised.

Question 22

describe which transducer(s) you would use to perform the ultrasound scan: thick-set patient with thyroid gland enlargement

Answer 22

Lower-frequency probes with deeper sound penetration but less spatial resolution may be needed in the setting of a large patient body habitus or to evaluate large thyroid glands.
initially, a high frequency linear array transducer should be used. It may be necessary to reduce the operating frequency if possible to get better depth penetration. A mid to high frequency convex linear array transducer may then be required to further image the gland, to allow better imaging of any retrosternal extension and to fully image the length of each lobe. Dual imaging may be helpful with the linear array to measure the gland dimensions if available.

Question 23

describe which transducer(s) you would use to perform the ultrasound scan: average size patient with a normal thyroid gland;

Answer 23

a high frequency linear array transducer should be the transducer used for all imaging, except for the longitudinal dimensions if dual imaging is not available. In this case a high frequency convex linear transducer should be used.

Question 24

describe which transducer(s) you would use to perform the ultrasound scan: palpable, superficial mass, ? thyroid in origin.

Answer 24

initially, a high frequency linear array transducer should be used to examine the thyroid gland and neck region. A high frequency convex linear array may then be required to adequately assess the true length of the lobes, otherwise dual imaging can be utilised. The mass should be further examined, due to its superficial nature, by a high frequency compact linear type probe if available to obtain better near-field resolution. If one is not available in your department, utilise a gel stand-off pad as this will help to reduce near field reverberations.

Question 25

Using a line diagram, draw the planes in which you would measure the thyroid gland.

Answer 25

``` Transverse: • Widest diameter of each lobe • AP diameter of the isthmus Longitudinal: • longest length/bi-polar measurement of each lobe and a depth measurement in this plane at the deepest section of the lobe. ```

Question 26

During the course of the scan, a patient who has until now been accepting of the procedure, refuses to continue with the scan any longer. List reasons why this patient may have withdrawn consent.

Answer 26

Environmental factors: • the room may be too hot, too cold, too noisy, too smelly. • the bed or scanning position may be too uncomfortable to tolerate further. Sonographer factors: • you may not have explained the procedure fully to the patient and are doing something they did not expect. • you may be communicating poorly with the patient, ignoring them, being rude or not explaining what you are doing. • Pressing too hard on their neck while scanning, causing pain or difficulty in swallowing or breathing. • Leaning on the patient's chest/breasts, even if inadvertantly. Department factors: • Rudeness of staff, whether real or perceived; this may include the receptionist, nurse/aid, sonographer or sonologist. • Continual interruption in the ultrasound room by other staff members or phone calls. • Excessive waiting while checking the films or seeking the sonologist. Patient/disease process factors: • Some patients with abnormally functioning thyroid glands may experience episodes of paranoia and/or depression. They may be very sensitive to anything you may say to them. • The neck or mass may be very tender, especially when being scanned. • The patient may be afraid of what the abnormality may be; e.g. cancer. This may be exacerbated if there is a relevant family history or if they are present due to a recurrence of a previous problem.

Question 27

Summarise fine needle aspiration biopsy advantages and disadvantages

Answer 27

``` Fine needle aspiration biopsy Advantages: • minimal materials (usually a very simply procedure) • inexpensive • quickly performed • local anaesthetic often not used • minimal discomfort (usually) • small bruise only (usually) ``` Disadvantages: • sample may be inadequate ( reduced if pathologist is present to check sample ) • false positive/false negative/equivocal aspirates • dependence of cytopathology expertise • specific tissue-related potential pitfalls.

Question 28

Summarise core biopsy advantages and disadvantages

Answer 28

``` Core Biopsy Advantages: • inexpensive • relatively atraumatic • may obviate the need for open biopsy • higher diagnostic yield (though there is some varying opinion about this) ``` Disadvantages: • greater chance of local haemorrhage due to larger bore needle used • tracheal perforation and other complications as there is probably reduced control of the needle depth with this procedure compared to FNA. • potential for facial nerve damage • possibility of tumour seeding, but very little evidence.

Question 29

Ultrasound features that favour a benign thyroid lesion:

Answer 29

1.Internal consistency • Solid, this is variable as malignant nodules may also be solid. • Cystic, many benign nodules undergo cystic degeneration or internal haemorrhage and therefore have cystic components, though some malignant lesions have cystic varieties and may also undergo necrosis. • "Comet-tail‟ artefacts within a mixed or cystic mass are generally associated with benign colloid nodules 2.Echogenicity compared with normal thyroid tissue • Hyper-echoic nodules are more likely to be benign, then iso-echoic. 3.Margination • Margins are usually well-defined, smooth and sharp. 4.Calcification • If calcifications are present, they are usually coarse and irregularly distributed, or have a peripheral ("egg shell‟) pattern. 5.Peripheral anechoic halo • A complete, thin halo is more common in benign lesions. The halo is caused either by the capsule of the nodule or compressed thyroid vessels. 6.Co-existing multinodularity • Multiple nodularity used to be an indicator for benign disease, but benign and malignant disease can co-exist, though this is not common. • Solitary nodules are statistically going to be benign due to the low incidence of thyroid carcinoma. 7.Vascularity • The most common vascular pattern is peripheral flow with little internal flow, if at all. • There will be no flow in septae. • Functioning adenomas may have increased internal flow, so need to be correlated with an isotope scan as they should be "hot‟. 8.Surrounding structures • No invasion of the margins of lesion or local spread should be seen. • There should be no associated adjacent lymphadenopathy, unless inflammatory in nature.

Question 30

Ultrasound features that favour a malignant thyroid lesion

Answer 30

1.Internal consistency • Usually have a solid appearance, but may be mixed and/or cystic (for example, papillary carcinoma). 2.Echogenicity compared with normal thyroid tissue • Hypo-echoic or iso-echoic are usually seen. 3.Margination • Margins are usually irregular and poorly-defined. 4.Calcification • Punctate, fine scattered (for example, psammoma bodies in papillary carcinoma) calcifications are often found, but those with medullary carcinoma may be more coarse. 5.Peripheral anechoic halo • A partial, thick halo may be present or no halo seen. 6.Co-existing multinodularity • Malignant lesions are usually solitary (though papillary carcinoma may be multi-centric). 7.Vascularity • Malignant nodules may have very variable flow patterns, but a nodule with increased peripheral flow, multiple vascular poles and chaotic, internal flow is more likely to be malignant, especially if it is a cold lesion on an isotope scan. • Vascularity within septae is a good indicator of a malignant cystic lesion. 8.Surrounding structures • Invasion of any capsule of the lesion is common. • Local invasion, that is, involvement of the strap muscles (as seen by a loss of fascial planes between the strap muscles and the thyroid gland with ill-defined muscle outline), involvement of the trachea, oesophagus and recurrent laryngeal nerve) is a good indicator of malignant disease. • Associated lymphadenopathy is also common.

Question 31

Describe the ultrasound appearance of parathyroid adenoma

Answer 31

* Usually affects only one gland but may be multiple. * They are typically discrete and oval. * Usually small, 8-15 mm, but have been known to be up to 5cm in diameter. * A large adenoma may become complex in appearance when large due to cystic degeneration,internal haemorrhage and/or necrosis. * Rarely are calcifications present.

Question 32

Describe the ultrasound appearance of parathyroid cyst

Answer 32

* More common in women and usually occurs in one of the inferior glands. * Well-defined and thin-walled with anechoic centre. Some may have some internal debris or septae.

Question 33

Describe the ultrasound appearance of parathyroid hyperplasia

Answer 33

* It is not possible on ultrasound to differentiate between primary and secondary parathyroid hyperplasia as in both cases the glands have increased as a compensatory mechanism * All four glands are symmetrically and equally enlarged. * Hypo-echoic, usually, but may be iso-echoic compared to the thyroid gland. * Calcifications may be present. * Whilst oval in shape, hyperplastic parathyroid glands are typically more spherical than adenomas. * Usually hyperplastic glands are quite vascular with arterial internal flow.

Question 34

Describe the ultrasound appearance of parathyroid carcinoma

Answer 34

* Usually affects only one gland and is quite rare. * They are usually hypo-echoic when compared to the thyroid gland. * Carcinoma may be lobulated and heterogenous due to necrosis. * Local invasion may be noted and adjacent lymphadenopathy. * Calcifications may be present.

Question 35

Describe and draw the various possible locations for thyroglossal duct cysts.

Answer 35

Thyroglossal duct cysts may form anywhere along the course followed by the thyroglossal duct during the decent of the thyroid gland from the tongue. Normally this duct atrophies and disappears. Most cysts are found either in the anterior neck just inferior to the hyoid bone or under the tongue. Following infection of a cyst, a perforation of the skin may occur, forming a thyroglossal duct sinus usually in the anterior neck in the midline anterior to the laryngeal cartilages.

Question 36

A newly recognised technique for considering the significance of enlarged lymph nodes is to assess their blood flow characteristics. Describe the various vascular appearances of cervical lymph nodes and their relevance.

Answer 36

Most normal or reactive lymph nodes will show the following vascular appearances: • no flow (due to the low flow velocity or low number of red blood cells ) or a few intranodal dots; and • hilar flow with or without peripheral branches from the longitudinal hilar vessels. Most malignant nodes are more likely to have the following vascular appearances: • displacement of the hilar vessels; • aberrant vessels; • missing intranodal flow signals; • sub-capsular or peripheral flow; and • chaotic flow patterns of the Doppler traces; • These patterns are subject to variations and are by no means 100 percent accurate. They do, though, help raise the suspicion of malignancy.

Question 37

Describe the causes and ultrasound appearance of Localised inflammatory disease of the salivary glands (Acute/chronic sialadenitis )

Answer 37

Acute/chronic sialadenitis • This may be due to viral, bacterial or autoimmune causes. • There may be predisposing factors such as duct obstruction, dehydration, debilitation and immunosuppression that reduce salivary secretions. Ultrasound appearances • The affected salivary glands will be enlarged and hypoechoic. • The gland parenchyma will be heterogenous (this may be due to microabscesses, duct dilatation and/or retention cysts). • Abscess formation may follow (supporative sialadenitis) , ill-defined hypoechoic mass, frank fluid may be detected and hyperechoic foci due to gas bubbles. • There is no mass effect, i.e. displacement of the duct and vessels. • Ultrasound-guided abscess drainage may be useful to aid treatment.

Question 38

Describe the causes and ultrasound appearance of Localised inflammatory disease of the salivary glands (Acute viral Inflammation)

Answer 38

* This is usually due to mumps, commonly affecting the parotid glands and may be uni- or bilateral. * It is important to exclude abscess formation. * This condition may progress to chronic sialadenitis. * In children, viral salivary gland infections are the most common cause of acute inflammation. Endemic viruses, including mumps, mononucleosis, and cytomegalovirus (CMV), are the most common viral causes, causing painful unilateral or bilateral swelling of the salivary tissue. In 85% of cases, the parotid gland is involved. Although less prevalent with the advent of immunization, mumps is still the most common cause of parotitis Ultrasound appearance • The affected gland will exhibit enlargement with an hypoechoic appearance. • With ultrasound, viral salivary infections show a diffusely enlarged gland that may have a normal, heterogeneous and/or hypoechoic echotexture with increased vascularity. Frequently there is bilateral involvement, although unilateral involvement may be seen in up to one-third of patients.

Question 39

Describe the causes and ultrasound appearance of Localised inflammatory disease of the salivary glands (Juvenile (recurrent) parotitis )

Answer 39

Juvenile (recurrent) parotitis is the most common cause of childhood parotid swelling in developed countries. This disorder manifests with intermittent pain, fever, and unilateral or bilateral parotid swelling. The submandibular and sublingual glands are not affected, and there is no known cause for the recurrent parotitis. Differential diagnosis includes mumps or suppurative parotitis, which is excluded by lack of pus from the parotid duct. Age at presentation is typically 3 to 6 years, and the episodes tend to cease near puberty or in late adolescence. Ultrasound is the favored imaging approach, demonstrating enlarged parotid glands containing multiple round, hypoechoic areas measuring 2 to 4 mm in diameter, likely representing peripheral sialectasis and lymphocytic infiltration. Some glands may be hypervascular, secondary to acute inflammation.

Question 40

Describe the causes and ultrasound appearance of Localised inflammatory disease of the salivary glands (Chronic sialadenitis)

Answer 40

Chronic sialadenitis is caused by an inflammatory process that damages the acini, altering the drainage system of the gland. The etiology may be infectious or noninfectious. Clinically, patients have gland swelling and pain, particularly postprandial. Patients with chronic sialadenitis on sonography often demonstrate a heterogeneous gland with small, punctate, echogenic areas or with multiple hypoechoic areas. Punctate areas are believed to represent mucus in the dilated ducts or walls of the dilated ducts. The hypoechoic areas likely represent edema and sialectasis. Increased vascularity can be demonstrated in areas of abnormal echotecture. Findings may be bilateral and associated with intraglandular or adjacent lymph node involvement.

Question 41

Describe the causes and ultrasound appearance of Localised inflammatory disease of the salivary glands (Sialectasis)

Answer 41

Sialectasis • This is dilatation of the tertiary intraglandular ducts. • Sialography may be more useful than ultrasound for this condition, but it may help exclude others.

Question 42

Describe the causes and ultrasound appearance of Localised inflammatory disease of the salivary glands (Sjögren syndrome)

Answer 42

Sjögren syndrome • Sjögren syndrome is a common auto-immune related disease affecting the salivary and lacrimal glands. • Almost affects only women who present with dry eyes and mouth, glandular enlargement and reduced secretions. • Sjögren syndrome is an autoimmune disorder that results in inflammation and destruction of the exocrine glands, primarily lacrimal and salivary tissue. These patients are usually monitored with ultrasound because of increased risk for lymphoma. Ultrasound appearance • In the early stages, the gland may have a normal texture with or without diffuse enlargement. • Later stages have multiple cystic lesions within an inhomogeneous, hypoechoic, hypervascularised gland. • Chronic disease may cause the gland to reduce in size. • It is difficult to determine with ultrasound imaging. • You may find an inhomogeneous appearance.

Question 43

Describe the causes and ultrasound appearance of Localised inflammatory disease of the salivary glands (Sarcoidosis)

Answer 43

Sarcoidosis • Sarcoidosis is rare, usually affects the submandibular gland. • The patient presents with a lump, with or without pain. • Sarcoid is an idiopathic granulomatous disease that is uncommon in children. Parotid involvement, noted in 30% of patients, may be the only initial finding. Ultrasound appearance • A diffusely hypoechoic gland of normal or increased size.

Question 44

Describe the causes and ultrasound appearance of Localised inflammatory disease of the salivary glands (Post-radiotherapy of the neck)

Answer 44

• This may often cause localised pain and swelling of the salivary glands, especially the submandibular. Ultrasound appearance • In the acute phase, there will be increased gland size with an hypoechoic appearance. • In the chronic phase, you may find a small, atrophied and hypoechoic gland.

Question 45

List the vessels responsible for the arterial supply and venous drainage of the breast.

Answer 45

Arterial: • internal thoracic artery, via the medial mammary and anterior intercostal branches; • lateral thoracic and thoracoacromial arteries; and • posterior intercostal arteries. Venous: • mainly to the axillary vein via the lateral thoracic and lateral mammary veins; and • also the internal thoracic and medial mammary veins.

Question 46

List the pathways of lymphatic drainage of the breast

Answer 46

Lymph passes from the nipple, areola and lobules of the gland through intramammary nodes and channels to the subareolar lymphatic plexus (Sappey’s Plexus). From this plexus drainage takes place through three main routes that parallel venous tributarie Axillary or lateral pathway • Most lymph (>75%) especially from the lateral side of the breast, drains to the axillary lymph nodes. Internal mammary pathway • Most remaining lymph, particularly from the medial breast quadrants, drain to the parasternal lymph nodes or to the opposite breast. retromammary pathway • Lymph from the deeper portion of the breast • drains to the subclavicular plexus Lymph from the inferior quadrants may pass deeply to the abdominal lymphnodes.

Question 47

Describe the normal ultrasound appearances of glandular tissue/parenchyma

Answer 47

Glandular tissue/parenchyma: usually homogeneously echogenic; some hypoechoic areas within may represent ducts or fat lobules.

Question 48

Describe the normal ultrasound appearances of Subcutaneous fat/fat lobules

Answer 48

Subcutaneous fat/fat lobules: hypoechoic compared to the glandular tissue. Some striations may be seen within. Fat lobules are usually round but may have a variable shape. Subcutaneous fat lobules are usually larger than those in the retromammary layer.

Question 49

Describe the normal ultrasound appearances of Pectoral muscle

Answer 49

Pectoral muscle: hypoechoic with striations.

Question 50

Describe the normal ultrasound appearances of The retro-areolar region

Answer 50

The retro-areolar region: some shadowing from the nipple may be noted; often hypoechoic ducts may be seen terminating under the nipple.

Question 51

Describe the normal ultrasound appearances of Cooper's ligaments

Answer 51

Cooper's ligaments: thin, echogenic lines, may not always be seen as this depends on their angle relative to the probe. They may be seen extending from the glandular tissue to the superficial layer of the superficial fascia.

Question 52

Describe the normal ultrasound appearances of The skin

Answer 52

The skin: two thin echogenic lines either side of a hypoechoic band; may be thicker inferiorly in the breast at the inframammary fold, but is usually approximately 2mm in thickness.

Question 53

Describe a 'TDLU' and discuss why it is important.

Answer 53

A TDLU is a terminal duct lobular unit. This is the secreting unit of the breast, containing the terminal duct and mammary lobule (oval structures composed of acini or small ductules). During pregnancy they expand and secrete milk. The milk/secretions are then delivered into the larger duct system from the TDLU to the interlobular or segmental duct, then to the lactiferous sinus and then collecting duct at the nipple. The TDLU is important because many benign and malignant lesions can arise within it. These include cysts, adenosis, hyperplasia, fibroadenoma and most carcinomas.

Question 54

What are the three helpful rules to remember when correlating mammo with ultrasound?

Answer 54

* If a lesion is in the lateral position of the breast in the CC, it will be projected high in the MLO.(ie it will actually be lower than seen on the MLO) * If a lesion is in the medial position of the breast in the CC, it will be projected low in the MLO.(ie it will actually be higher than seen on the MLO) * The more medial or lateral it is, the lower or higher it will be projected in the MLO in relation to the nipple.

Question 55

If a lesion is in the lateral portion of the breast in the CC and lies at the level of the nipple in the MLO, where should it actually lie in the breast?

Answer 55

Lower lateral quadrant, lateral lesions are projected higher on the MLO.

Question 56

If a lesion is in the medial portion of the breast in the CC and in the mid part of the breast in the MLO, where should it actually lie in the breast?

Answer 56

Upper medial quadrant, medial lesions are projected lower on the MLO.

Question 57

If a lesion is in the central portion of the breast in the CC and in the mid part of the breast in the MLO, where should it actually lie in the breast?

Answer 57

In the upper breast around 12 o'clock.

Question 58

If a lesion is not seen in the CC and lies high in the superior part of the breast in the MLO, where could it actually lie in the breast?

Answer 58

It is most likely to be actually in the axilla or the axillary tail. If it was lower in the MLO, it could lie in the supero-medial portion of the breast.

Question 59

What two phenomena must be considered during Sonographic-mammographic correlation of shape

Answer 59

Sonographic-mammographic correlation of shape must consider two phenomena: partial compressibility and rotary forces applied during compression. This can be demonstrated when a partially compressible spherical mass on mammography appears oval on ultrasound (see Fig. 21.63). When the mammographic lesion is spherical and not compressible, the shape will be spherical on sonography as well.

Question 60

What must be considered during Sonographic-mammographic correlation of location and position

Answer 60

Location or Position Correlation Because mammographic compression pulls a lesion away from the chest wall and sonographic compression pushes the lesion closer to the chest wall, lesions usually appear much closer to the chest wall on sonography than on mammography. Lesions that appear to lie several centimeters from the chest wall on mammography may appear to lie very close to the chest wall, even indenting the chest wall musculature, on sonography.

Question 61

What must be considered during Sonographic-mammographic correlation of size

Answer 61

Mammographic-sonographic correlation of size should take into account everything that is water density on the mammogram. Therefore an oval, 3-cm, circumscribed mass on mammography could correlate with multiple different types of masses on ultrasound that all measure 3 cm, such as (1) a cyst, (2) a solid nodule with a thin echogenic capsule, (3) a cyst that contains a mural nodule, (4) a 3-cm collection of fibroglandular tissue, (5) a smaller cyst, or (6) a solid nodule surrounded by fibroglandular tissue. All six sonographic structures would constitute a perfect mammographic-sonographic size match. Measurements on ultrasound should be made outside-to-outside to include the capsule that surrounds the cyst or solid nodules, because the capsule is water density and will be included in the measurement of the lesion on the mammogram.

Question 62

Describe the width X depth ratio and its significance.

Answer 62

The width X depth ratio is one of the many characteristics used in describing breast lesions in an effort to try to determine the potential malignancy of the lesion. Lesions that are wider than they are high are more likely to be benign than those lying more upright (when scanning in the supine position). Therefore, a high ratio suggests a likely benign lesion, whilst a low ratio suggests malignant potential. This type of shape suggests lesion growth that is across normal tissue planes and indicates malignant potential. Fibroadenomas usually grow within the tissue planes, flattening with the pressure of the fascial planes. Some cysts, though, may be very round. Therefore, the ratio should be used in combination with the other ultrasound characteristics when assessing a breast lesion.

Question 63

list the ultrasound characteristics you would most likely find in benign lesions

Answer 63

* shape – round, oval , eliptoid * texture - homogeneous * echogenicity - anechoic, hyperechoic * internal contents – solid, cystic * presence of calcifications - only if large and smooth * margin definition - smooth, macro-lobulations, sharp, thin halo or capsule * posterior sound transmission - enhancement, shadow, no change * orientation to skin – parallel to skin, along skin planes * width X depth ratio - wider than tall * mobile, compressible * no architectural distortion /Cooper's ligament distortion * no disruption to superficial or deep fatty and fascial layers * no nipple inversion/retraction * no abnormal axillary lymphadenopathy

Question 64

list the ultrasound characteristics you would most likely find in malignant lesions

Answer 64

* shape – round, irregular * textures – heterogeneous * echogenicity - hypoechoic * internal contents – solid, mixed * presence of calcifications – fine * margin definition- irregular, spiculated, ill-defined, micro-lobulations, thick, irregular capsule * posterior sound transmission - shadowing , no change * orientation to skin, more upright * width X depth ratio – low, more round or upright shape * immobile, non-compressible, hard, irregular * architectural distortion /Cooper's ligament distortion * disruption to superficial or deep fatty and fascial layers * recent nipple inversion/retraction * abnormal axillary lymphadenopathy

Question 65

Describe the pathophysiology of fibrocystic breast change

Answer 65

Fibrocystic disease in the breast is a reactive and degenerative change, partially due to the consequences of hormonal stimulation and the breast's reaction to this, and partially due to the consequences of aging. It does not usually occur prior to puberty and any symptoms gradually improve post-menopause. Usually both breasts are affected, but there is often asymmetry. Lumps are often easily palpable and often fluctuate in size. The breasts may have a nodular feel and are usually very tender, especially premenstrually.

Question 66

Describe the process of fibrocystic change

Answer 66

The normal breast tissue responds to variations in hormone levels throughout the menstrual cycle in regard to proliferation and accumulating fluid. The breast undergoing fibrocystic change does so in a hyperplastic reactive and degenerative way. The typical features of fibrocystic change include epithelial proliferation, fibrosis and cysts. A less common feature is intraductal papillomatosis. Fibrosis occurs when the loose intralobular connective tissue is replaced with dense connective tissue. The ductal epithelium proliferates, ducts dilate and become trapped by these dense connective tissue strands, leading to cyst formation. The fibrous strands also undergo degenerative change due to interruption of blood flow, presenting eventually as stromal calcification. Epithelial proliferation occurs in the form of ductal budding and crowding – sclerosing adenosis. Some breasts develop intraductal cell proliferation and may grow small intraductal papillomas (these have some malignant potential).

Question 67

What are the common ultrasound appearances of fibrocystic change?

Answer 67

Cysts Simple cysts • echo-free contents • round/oval (round cysts may be under tension more than flaccid/flattened cysts) • posterior enhancement • smooth/thin walls • edge refraction; reverberation artefacts within are common • usually compressible and may feel mobile Complex cysts • septations/lobulations • debris (low level echoes maybe due to internal haemorrhage, milk, cellular material, inspissated/concentrated secretions) • wall thickening, especially if infection present or recent biopsy attempt • intracystic mass – for example, papilloma • reduced posterior enhancement, common if small or containing low level echogenic material Intraductal papillomas • medium-level soft tissue mass attached to one wall of the duct; may see blood flow to it, may also cause the duct to be dilated, may obstruct and cause distal dilatation. Fibrosis and epithelial proliferation • increased echogenicity and often coarseness to the glandular and stromal tissue • smooth calcifications may be present

Question 68

list the generally accepted risk factors for women developing breast cancer

Answer 68

* maternal relative with breast cancer (for example, mother, sister, daughter, aunt), especially if young * increasing age – rare under the age of 30, risk increases steadily with age * BRCA1 and BRCA2genes. BRCA1 occurs in 1:800 women. BRCA2 is less common, but is associated with early onset breast carcinoma. * long reproductive cycle – increased risk with early period onset(<15)and/or late menopause(>50) * obesity, high dietary fat intake in postmenopausal women * nulliparity, increased risk if never pregnant, slightly less if previously pregnant but no live births * late age at first pregnancy, that is, first child born to women over 30 * atypical epithelial hyperplasia, due to changes in ductal epithelium * previous breast cancer * previous endometrial or ovarian cancer * previous radiation to the breast * hormone replacement therapy

Question 69

Discuss the clinical indications of FNA of the breast

Answer 69

* tends to be used more as a first choice where the lesion is expected to be cystic or mainly cystic to facilitate aspiration; and * often performed prior to a core biopsy to obtain a cytological specimen.

Question 70

Discuss the advantages of FNA of the breast

Answer 70

* useful aspiration tool for cystic/mainly cystic lesions; * relatively quick and easy to perform in trained hands; * well-tolerated by most patients (often even without the use of local anaesthetic); and * low chance of bleeding due to fine gauge needle used.

Question 71

Discuss the disadvantages of FNA of the breast

Answer 71

* yields only a cytological specimen; and | * sometimes the cellular material may be very sparse, even insufficient, especially in some benign lesions.

Question 72

Discuss the clinical indications of core biopsy of the breast

Answer 72

* more commonly used where the lesion is suspected to be malignant or inconclusive; and * where a previous FNA has been inconclusive.

Question 73

Discuss the advantages of core biopsy of the breast

Answer 73

* yields a histological specimen which has the potential to demonstrate the invasiveness of the tumour; and * usually quite well-tolerated by outpatients with local anaesthetic to the breast.

Question 74

Discuss the disadvantages of core biopsy of the breast

Answer 74

* technically more demanding for the operator and patient; * more traumatic to the patient; * greater propensity for the breast to bleed (haematoma development due to larger gauge needle used); and * chance of tumour seeding along track of needle possible (sometimes disputed).

Question 75

Discuss early complications of breast implant and the ultrasound appearances

Answer 75

infection or haematoma These are usually clinically obvious, but ultrasound appearances may show fluid collections of varying echogenicity. Sometimes small anechoic fluid collections may have a simple appearance soon after surgery. The size and position of the collection should be noted. Peri-implant fluid collections may be present for some time with the saline implant.

Question 76

Discuss late complications of breast implant and the ultrasound appearances (Deformity due to leakage or rupture:)

Answer 76

Deformity due to leakage or rupture: This may appear as distortion or lobulation of the prosthesis or as cystic spaces around the implant. Unencapsulated implants may bulge and distort under normal tissue pressures and still not be ruptured. Free silicone may be diffusely extravasated or appear in lumps. Free silicone rupture may give a classical „snow storm‟ appearance – diffuse fine low-level echo shadowing. A ruptured implant will deflate rapidly and may be due to trauma or totally unexpected. Silicone may extravasate into the surrounding tissue (extracapsular rupture) or be contained within the fibrous capsule formed around the implant (intracapsular rupture). It is very difficult to determine whether it is an encapsulated rupture or merely a bulge in the implant. A sign of an early rupture is the „linguine‟ sign, whereby the recoil of the envelope causes it to contract into the centre of the bag. Implant rupture may also give the ultrasound appearance of multiple echogenic lines either within or below the anterior surface. Fragmentation of polyurethane bags may also cause long-standing fluid collections, thought to be due to a chronic inflammatory reaction.

Question 77

Discuss late complications of breast implant and the ultrasound appearances (capsular fibrosis)

Answer 77

This is usually more of a clinical diagnosis as the implant capsule becomes firm and hard. On ultrasound, it may appear as bright parallel lines at the surfaces of the prosthesis. The implant may appear distorted.

Question 78

Discuss late complications of breast implant and the ultrasound appearances (echogenic masses)

Answer 78

Calcification and oil cysts may be present. These may appear as echogenic masses of variable hyperechogenicity. Silicone granulomas are a reasonably common appearance, forming at the surface of the silicone bag. They are usually quite palpable and have the ultrasound appearance of an echogenic, well-circumscribed rounded structure close to the edge of the prosthesis. Posterior shadowing will be present. Fragmentation of polyurethane bags may cause debris within fluid collections around the implant

Question 79

Lit the possible late complications of breast implants

Answer 79

Deformity due toLeakage and rupture Capsular fibrosis Echogenic masses Contraction

Question 80

Discuss late complications of breast implant and the ultrasound appearances (contraction)

Answer 80

Due to tissue pressures, undulations and folds may appear within the implant. It may be sometimes difficult to determine if the appearances are of folds or rupture of an implant. Some folds are normal due to tissue moulding.

Question 81

Discuss breast lesions and malignancy and breast implants

Answer 81

Breast lesions are still just as likely to appear in the augmented breast. Ultrasound is a useful aid in detecting breast cancer when implants are present as the implant can greatly reduce the quality of the breast imaging in mammography. Studies at present do not show any increased incidence of breast carcinoma when implants are present, but may reduce the ability of early detection via mammography.

Question 82

Discuss the advantages of MRI of the breast over mammography and ultrasound.

Answer 82

* more reliable in demonstrating implant rupture; * breast tissue/chest wall posterior to the implant is well demonstrated; * implant internal anatomy well imaged; * excellent detection of free silicon in soft tissues remote from the implant; and * silicon uptake in regional lymph nodes can be detected.

Question 83

Discuss the indications of an ultrasound guided pleural drainage

Answer 83

* to take a sample of a pleural fluid of unknown origin for diagnosis; * to remove as much pleural effusion as possible as a therapeutic procedure so that the patient can breathe more easily and comfortably; and * to sample a pleural, chest wall or mediastinal mass (dependent on easy access under ultrasound control).

Question 84

Discuss the advantages of an ultrasound guided pleural drainage

Answer 84

* usually quick to perform; * real-time visualisation (as opposed to CT); * optimal plane easily identified; * can be performed with patients in varying positions (often sitting is easier for the patient with breathing difficulties and gravity helps the fluid to settle in the sampling region); * portable, therefore can be performed at the patient‟s bedside; * no use of ionising radiation; and * usually well-tolerated by the patient.

Question 85

Discuss the disadvantages of an ultrasound guided pleural drainage

Answer 85

* if the fluid cannot be visualised and a good path for access identified, the procedure should not go ahead (that is, lung lesions can only be sampled if they lie against the chest wall and do not lie under the rib); and * there is a reasonable chance of pleural being nicked by needle (pneumothorax may be elicited).