Head And Neck Flashcards
USF of lipoma
Well-defined, compressible, elliptical mass with long axes parallel to skin • Multiple echogenic lines oriented parallel to transducer are present: “Feathered” or “striped” appearance • No evidence of calcification, nodularity or necrosis • 75% hyperechoic, 25% iso/hypo echoic relative to muscle • No deep acoustic enhancement or attenuation • Displacement but no infiltration/stranding adjacent structures of • Color Doppler: No significant vascularity within or around mass • Liposarcoma suggested by several findings • Presence of adjacent soft tissue stranding
Nodular mass, septation and vascularity within lesion • Cystic/necrotic areas and calcification within lesion • Benign symmetrical lipomatosis (BSL)/Madelung disease • Diffuse, lobulated, isoechoic “mass” with echogenic lines within but no vascularity on Doppler • Asthe fat is unencapsulated, USis not able to define degree of involvement; CT/MR better define distribution of fat and compression of vital structures • May mask underlying neck malignancy; MR/CT evaluate it better than US
Checklist for lipoma
Consider CHECKLIST
• All lipomas should be scrutinized for presence of internal nodularity, stranding, vascularity, calcification • Liposarcoma if there is prominent internal stranding, nodularity or heterogeneity, calcification, necrosis and vascularity
Image Interpretation Pearls
• Define extent of large lipoma of extra cranial head & neck in terms of spaces involved • Surgeon needs to know if lesion is trans-spatial
USF of differentiated thyroid CA
Sonographic features of papillary carcinoma • Solitary or multi focal, on US 10-20% are multifocal, solid (70%) & hypoechoic (77-90%) • Punctate microcalcification is highly specific for paplllary carcinoma, typically fine calcification/echogenic foci, ± posterior shadowing • Majority are ill-defined with irregular outlines but 15-30% of tumors may show an incomplete halo • Large tumors may show signs of invasion to strap muscles, esophagus, trachea, recurrent laryngeal nerve, neck vessels
Color Doppler: Multiple, chaotically arranged vessels within the nodule & wall & septa in nodules with cystic change
Nodes predominantly hyperechoic (80%) compared to muscles with punctate microcalcification (50%) • Sonographic features of follicular carcinoma • Ill-defined solid tumor with hypoechoic, heterogeneous architecture • Hypoechoic component to an otherwise iso/hyperechoic margins/capsule solid mass; thick irregular • Obvious extra thyroid invasion into trachea, esophagus, strap muscles & large vessels • Color Doppler: Profuse, chaotic perinodular & intranodular vascularity (intranodular more than perinodular)
Checklist for differentiated thyroid CA
Image Interpretation Pearls • Consider DTCa in patients with ill-defined, solid, hypoechoic, hypervascular intra thyroid mass, ± extra thyroid extension, ± metastatic nodal/distant metastases
USF of medullary thyroid CA
Solitary or multiple or diffuse involvement of both lobes (especially familial type) • Located predominantly in lateral upper 2/3rd of gland in sporadic form • Hypoechoic, solid tumor, frequently well-defined but may have infiltrative borders • Echogenic foci in 80-90% representing amyloid deposition & associated calcification • Echogenic foci are dense & coarse + shadowing compared to papillary carcinoma • Lymph nodes along mid & low internal jugular chain, superior mediastinum • Lymph nodes predominantly hypoechoic with coarse shadowing calcification • Doppler: Chaotic intra tumoral vessels
Doppler: Chaotic intranodal vessels • On USMTC is invariably mistaken for papillary carcinoma (which is much more common) & diagnosis made only after FNAC • Sonographic clue to MTC rather than papillary carcinoma is presence of coarse shadowing tumoral calcification (punctate in papillary) & hypoechoic nodes (hyperechoic in papillary) with coarse shadowing • Evaluate adrenal & parathyroid gland if MTC is part of type 2 multiple endocrine neoplasia (MEN)
Checklist for medullary thyroid CA
Image Interpretation Pearls •usappearance may exactly mimic papillary thyroid carcinoma
USreadily evaluates post-operative thyroid bed and neck but CT or MIl.imaging are necessary for detection of nodal metastases in mediastinum as well as distant metastases
USF of differentiated thyroid CA
Sonographic features of papillary carcinoma • Solitary or multi focal, on US 10-20% are multifocal, solid (70%) & hypoechoic (77-90%) • Punctate microcalcification is highly specific for paplllary carcinoma, typically fine calcification/echogenic foci, ± posterior shadowing • Majority are ill-defined with irregular outlines but 15-30% of tumors may show an incomplete halo • Large tumors may show signs of invasion to strap muscles, esophagus, trachea, recurrent laryngeal nerve, neck vessels
Color Doppler: Multiple, chaotically arranged vessels within the nodule & wall & septa in nodules with cystic change
Nodes predominantly hyperechoic (80%) compared to muscles with punctate microcalcification (50%) • Sonographic features of follicular carcinoma • Ill-defined solid tumor with hypoechoic, heterogeneous architecture • Hypoechoic component to an otherwise iso/hyperechoic margins/capsule solid mass; thick irregular • Obvious extra thyroid invasion into trachea, esophagus, strap muscles & large vessels • Color Doppler: Profuse, chaotic perinodular & intranodular vascularity (intranodular more than perinodualr)
Checklist for differentiated thyroid CA
Consider DTCa in patients with ill-defined, solid, hypoechoic, hypervascular intra thyroid mass, ± extra thyroid extension, ± metastatic nodal/distant metastases
USF of medullary thyroid CA
Solitary or multiple or diffuse involvement of both lobes (especially familial type) • Located predominantly in lateral upper 2/3rd of gland in sporadic form • Hypoechoic, solid tumor, frequently well-defined but may have infiltrative borders • Echogenic foci in 80-90% representing amyloid deposition & associated calcification • Echogenic foci are dense & coarse + shadowing compared to papillary carcinoma • Lymph nodes along mid & low internal jugular chain, superior mediastinum • Lymph nodes predominantly hypoechoic with coarse shadowing calcification • Doppler: Chaotic intra tumoral vessels
Doppler: Chaotic intranodal vessels • On USMTC is invariably mistaken for papillary carcinoma (which is much more common) & diagnosis made only after FNAC • Sonographic clue to MTC rather than papillary carcinoma is presence of coarse shadowing tumoral calcification (punctate in papillary) & hypoechoic nodes (hyperechoic in papillary) with coarse shadowing • Evaluate adrenal & parathyroid gland if MTC is part of type 2 multiple endocrine neoplasia (MEN)
Checklist for medullary thyroid CA
usappearance may exactly mimic papillary thyroid carcinoma • USreadily evaluates post-operative thyroid bed and neck but CT or MIl.imaging are necessary for detection of nodal metastases in mediastinum as well as distant metastases
USF of anaplastic thyroid CA
Best diagnostic clue: Invasive, hypoechoic thyroid mass, ± focal calcification, ± necrosis against a background of MNG in elderly female • Heterogeneously enhancing lesion, diffusely infiltrating • Nodes are hypoechoic & necrotic in 50% • Color Doppler shows prominent, small, chaotic intranodular vessels • Necrotic tumor may be avascular/hypovascular (vascular infiltration/occlusion) thyroid gland • Ill-defined, hypoechoic tumor diffusely involving the entire lobe or gland • Background of multinodular goiter • Necrosis (78%), dense amorphous calcification (58%) • Dense calcification reflects MNG calcification • Extracapsular spread with infiltration of trachea, esophagus & perithyroid soft tissues • Thrombus in IJV and CA causing expansion & occlusion of vessels • Nodal or distant metastases in 80% of patients
Abnormal vascularity seen within metastatic nodes • Vascularity seen in thrombus in vessels suggesting it to be tumor thrombus & not venous thrombus • US is ideal bedside imaging tool to evaluate ATCa, its gross extension, nodal disease; it is readily combined with fine needle aspiration cytology (FNAC) to confirm diagnosis
Checklist for anaplastic thyroid CA
Consider
• Diagnosis is based on clinical evaluation, imaging & biopsy
Image Interpretation Pearls • Rapidly enlarging thyroid mass suggests DTCa or thyroid NHL
USF of thyroid non Hodgkin lymphoma
Best diagnostic clue: Rapidly enlarging, solid, non-calcified thyroid mass in elderly female with history of Hashimoto thyroiditis (HashT) • Background evidence of previous HashT: Echogenic fibrous streaks in lobulated, hypoechoic gland • Color Doppler: Thyroid nodules: Non-specific, nodules may be hypovascular or have chaotic intranodular vessels • Color Doppler: Nodes: Hypervascular nodes, central & peripheral vascularity Top Differential Diagnoses • Focal lymphomatous mass/nodule: “Pseudocystic” appearance with posterior enhancement • Focal lymphomatous mass/nodule: Well-defined, solid, hypoechoic, heterogeneous, non-calcified • Diffuse involvement: Hypoechoic, rounded gland with heterogeneous echo pattern • Diffuse involvement: Simple thyroid enlargement, minimal change in echo pattern (often missed) • Lymphadenopathy: “Reticulated” echo pattern or “pseudocystic” echo pattern
Checklist for thyroid non hodgkins lymphoma
Rapidly enlarging thyroid mass in elderly patient is usually due to thyroid NHL or anaplastic carcinoma • Absence of calcification, invasion & necrosis, while not specific, are suggestive of NHL
USF for hashimotos thyroiditis
Acute focal HashT: Ill-def1Oed focal hypoechOlc areas f I h t” fit t’ representing areas 0 ymp ocy IC 10 I ~alOn • Acute diffuse HashT: Diffuse, hypoechOlc,., heterogeneous, micronodular echo pattern mvolv1Og the whole gland . • Chronic HashT: Enlarged, hypoechOlc, heterogeneous gland ~ith lobulated outli~es • Chromc ,Ha~hT:HypoechOlc areas separated by echoge~llc fibrous septa , • AtrophIC/end stage HashT: Small gland wlth heterogeneous echo pattern • Color Doppler: Acute focal/diffuse thyroiditis: Avascular gland , ..• • Chronic: Hypervascular when patient IS hypothyrold reflecting hypertrophic action of TSH
Chronic Following treatment when TSH returns to normal hypervasculanty decreases
rop !c, vascu ar ypo • There is an increased risk of non-Hodgkin lymphoma Wh (NHL) in Hashimoto th roiditis Yt ‘th H hTalways ‘t’ • en scannIng pa Ien s WI as evaluate thyroid (± FNAC) for developing NHL, • ~~~~t;ulge in the contour of the gland • Developing areas of ill-defined hypoechogenicity, focal or diffuse, ± mass effect • Lymphomatous adenopathy in adjacent neck
Checklist for Hashimotos
Consider CHECKLIST
• Rapid enlargement of thyroid in patient with history of Hashimoto = NHL until proven otherwise
Image Interpretation Pearls
• Important to follow-up ± aspirate under ultrasound any focal nodules because of increased risk of malignancy
USF of MNG
Solid nodules are often isoechoic with small proportion being hypoechoic (5%) • Despite being unencapsulated, nodules are sharply defined with halo • Heterogeneous internal echo pattern with internal debris, septa, solid/cystic portions • Dense shadowing calcification (curvilinear, dysmorphic, coarse) • Nodules with comet tail artifact, highly suggestive of colloid nodule • Cystic component due to hemorrhage or colloid within nodule • Background thyroid parenchymal echoes are coarse & heterogeneous (fine bright echoes in normal gland)
Color Doppler: Peripheral vascularity> intranodular vascularity • Color Doppler: Septa, intranodular solid portions are avascular (organizing blood, clot) • Look for papillary carcinoma in MNG: Search for solid, ill-defined, hypoechoic nodule, punctate microcalcification & chaotic intranodular vessels • Main role of USin MNG is to identify presence of suspicious nodule & guide biopsy • Evaluate neck for suspicious/metastatic nodes & for any retrosternal extension
USF for Graves disease
Increase in volume of thyroid up to 90 mL • Hypoechoic, heterogeneous, “spotty” parenchymal echo pattern • Marked increase in parenchymal vascularity (turbulent flow with A-Vshunts), “thyroid inferno” • Such increase in vascularity is also seen in patients with recurrence • Spectral Doppler: Increase in peak flow velocity (up to 120 cm/s) as measured in inferior thyroid artery • Imaging in Graves disease is usually not required for patient management • Imaging of thyroid may be necessary in patients who fail medical treatment and in whom other types of thyroiditis are considered
Thyroid USmay also be indicated in patients who undergo radioactive iodine treatment, to establish thyroid volume • Patients with Graves disease may present with thyroid associated ophthalmopathy (TAO) • Patients have exopthalmos with bilateral enlargement of external ocular muscles (EOM)
Checklist for Graves
In patients with TAO, CT or MR may be indicated to confirm diagnosis if it cannot be established clinically
