DISORDERS OF THE THYROID GLAND Flashcards
Persistence of the THYROGLOSSAL DUCT along its migratory path
1 % will have malignancy - PAPILLARY THYROID CA
thyroglossal duct cyst
SISTRUNK OPERATION - excision of the entire cyst and central hyoid bone
Ectopic thyroid tissue located in the BASE OF TONGUE
FAILURE OF DESCENT of the THYROID ANLAGE
Lingual Thyroid
exogenous thyroid hormone - suppress TSH
RAI ablation then hormone replacement
Normal thyroid tissue found in the other compartments of the neck
Ectopic Thyroid
Maldevelopment an obstruction of lymphatic system
Sequestrations of lymphatic tissue develops which does NOT communicate with the lymphatic system
soft, compressible, non tender masses - LATERAL or POSTERIOR triangle of the neck
Cystic Hygroma
MRI - imaging modality
intralesional injection of a sclerosing agent (OK-432, Bleomycin)
COMPLETE SURGICAL RESECTION - preferred treatment with preservation of all vital neural and vascular structures
Staging of the Neck
N0 - no regional lymph node metastasis
N1 - metastasis in single ipsilateral node < 3 cm
N2a - metastasis in a SINGLE ipsilateral lymph node b/w 3-6 cm
N2b - metastasis in a MULTIPLE ipsilateral lymph node, < 6 cm
N2c - metastasis in a MULTIPLE ipsilateral lymph node, > 6 cm
N3 - metastasis in a lymph node > 6 cm
removes levels I to V cervical lymphatics, spinal accessory nerve, IJV and SCM
Radical Neck Dissection
Removes the SAME levels of cervical lymphatics as in RND BUT PRESERVES the spinal accessory nerve, IJV, SCM
Modified Radical Neck Dissection (Functional Neck Dissection)
Preserves lymphatic structures normally removed in an RND or MRND
Selective Neck Dissection
Supraomohyoid (I, II and III)
for ORAL CAVITY malignancies
Lateral Neck Dissection (II, III, IV)
for LARYNGEAL malignancies
Posterolateral Neck Dissection (II, III, IV and V)
for THYROID malignancies
MC benign salivary gland tumor
Pleomorphic adenoma
MC malignant salivary gland tumor
Mucoepidermoid Ca
Adult - 2nd MC -adenoid cystic ca - w/ propensity for
distant mets
Children - 2nd MC - acinic cell ca
Most important use if for monitoring of differentiated thyroid cancer recurrence after total thyroidectomy and RAI ablation
Serum Thyroglobulin
Sensitive marker for medullary thyroid cancer
Serum Calcitonin
LOW dose radiation (12-24 hrs half life)
for imaging thyroid tissues - lingual, ectopic metastatic
Iodine 123
HIGHER radiation - 8-10 days half life)
screen and treat differentiated thyroid cancers - papillary and follicular ca
Iodine 131
WHO Classification of Thyroid Size
GRADE I - no palpable or visible goiter
GRADE 2 - palpable goiter, NOT VISIBLE in NORMAL head position
GRADE 3 - palpable goiter, VISIBLE in NORMAL head position
Some Indications for THYROIDECTOMY
confirmed cancer or suspicious thyroid nodules
severe reactions to antithyroid medications
large goiters w/ compressive symptoms
reluctant to undergo RAI
Initial test that must be requested in the evaluation of thyroid nodules
Serum TSH
if euthyroid or hypothyroid — FNAB
if hyperthyroid — RAI scan
For detecting NON PALPABLE thyroid nodules, differentiating SOLID vs CYSTIC and identifying CERVICAL LYMPHADENOPATHIES
Thyroid Ultrasound
Most useful for LARGE, FIXED, SUBSTERNAL goiters and evaluation of LUNG METASTASES
CT Scan
For evaluation of EXTRATHYROIDAL TUMOR EXTENSION - hoarsenss, dysphagia, stridor, cough
MRI
Provides anatomic and physiologic information
Iodine Scan
hot or warm lesion - increased activity (< 5 % risk of malignancy)
cold lesion - traps less iodine than surrounding gland (20 % risk of malignancy)
Used to screen malignancies when other imaging studies are negative
Positron Emission Tomogram (PET) scan
Single most important test in evaluation of thyroid nodules
Fine Needle Aspiration Biopsy (FNAB)
at least 6 follicles w/ at least 10-15 cells from at least 2 aspirates
Features suggesting MALIGNANCY in a THYROID NODULE
Ultrasound of the Thyroid
hypoechogenecity microcalcifications irregular or blurred nodule margins increased nodular blood flow evidence of tumor invasion or regional lymph node metastases
Features suggesting MALIGNANCY in a CERVICAL LYMPH NODE
Ultrasound of the Thyroid
complex echo pattern or irregular hyperechoic small intranodular structures irregular diffuse intranodular blood flow Solbiati index (ratio of largest to smallest diameteer of a node = 1 - lymph node is more round than long
MC thyroid cancer
Papillary carcinoma
prior history of EXTERNAL RADIATIONS Orphan Annie Nuclei Psammoma bodies cervical lymph nodes - site of metastasis
Treatment for Papillary Carcinoma
High risk tumors/ bilateral - TT or NTT
< 1 cm, low risk, no hx of irradiation, no evident metastases - thyroid lobectomy
advanced tumors (T3 or T4) - neck dissection
Usually solitary and encapsulated lesions
Follicular carcinoma
iodine deficient areas cervical lymphadenopathy - uncommon CANNOT be diagnosed by FNAB (+) vascular and capsular invasion
Treatment for follicular neoplasm
Adenoma - thyroid lobectomy
Carcinoma - total thyroidectomy
Subtype of follicular carcinoma
multifocal and bilateral
Hurtle Cell Carcinoma
from OXYPHIL cells neck - common metastatic area
Arises from PARAFOLLICULAR cells at the SUPEROLATERAL lobes of thyroid gland
Medullary Thyroid Carcinoma
>50% - bilateral cervical lymphadenopathy produces CALCITONIN, CEA, CGRP, HISTAMINIDASE, SEROTONIN associated w/: MEN 2A: MTC, pheochromocytoma, primary HPT MEN 2B: MTC, pheochromocytoma, Marfanoid habitus, mucocutaneous ganglioneuromatosis
Treatment for Medullary Carcinoma
Total Thyroidectomy w/ Bilateral Central Neck Node Dissection
1 % o all thyroid malignancies; HIGHLY AGGRESSIVE tumor
Anaplastic carcinoma
giant and multinucleated cell - FNAB lymph node metastases
Treatment for Anaplastic Carcinoma
mostly palliative
TT or NTT
En Bloc resection if w/ extrathyroidal extension
adjuvant radiotherapy w/ or w/o chemotherapy
Postoperative Complications w/n 24 hrs of Thyroid Surgery
Hypocalcemia
Dyspnea
Dystonia
MC malignancy that metastasize to thyroid
Renal Carcinoma
Salivary Gland Tumors Risk of Malignancy
Sublingual - 100%
Submandibular - 50%
Parotid - 20%
75% of all salivary gland tumors occur in
Parotid Gland
MC location of SUPERNUMERARY GLANDS
Thymus
OTHER LOCATIONS: w/n the parenchyma of thyroid glands tracheoesophageal groove mediastinum anywhere along the neck
MC location of ECTOPIC PARATHYROID
Paraesophageal
Increased PTH from abnormal parathyroid glands
Etiology:
parathyroid adenoma
parathyroid hyperplasia
parathyroid carcinoma
Primary Hyperparathyroidism
kidney stones painful bones abdominal groans psychic moans fatigue overtones
increase serum Ca increase intact PTH or 2 site PTH levels decrease serum phosphate elevated 24 hr urine Ca
Treatment for Primary Hyperparathyroidism
Parathyroidectomy
Increased PTH in response to hypocalcemic states (chronic renal failure, inadequate calcium intake, gut malabsorption)
Secondary Hyperparathyroidism
Calciphylaxis - painful violaceous lesions on the extremities that may necrose and become gangrenous leading sepsis and death
Treatment for Secondary Hyperparathyroidism
Phosphate binding antacids
Cinacalcet (calcimimetic)
Oral calcium and vitamin D
for uncontrolled symptoms - 3.5 parathyroidectomy or total parathyroidectomy
+ autotransplantation
Persistent hyperparathyroidism and hypercalcemia following successful renal transplant or resolution of underlying
Tertiary Hyperparathyroidism
d.t. irreversible parathyroid gland hyperplasia w/ autonomous PTH production
MCC is thyroid surgery
DiGeorge syndrome - congenital absence of parathyroid gland
Hypoparathyroidism
tingling sensation on fingertips and around lips Chvostek sign - tapping on the facial nerve anterior to ear causes contraction of ipsilateral facial muscles Trousseau sign -carpopedal spasm after occlusion of blood to the forearm Tetany (worst case)
Treatment for Hypoparathyroidism
Calcium (IV gluconate)
Vitamin D supplementation
