DISORDERS OF THE THYROID GLAND

Question 1

Persistence of the THYROGLOSSAL DUCT along its migratory path
1 % will have malignancy - PAPILLARY THYROID CA

Answer 1

thyroglossal duct cyst

SISTRUNK OPERATION - excision of the entire cyst and central hyoid bone

Question 2

Ectopic thyroid tissue located in the BASE OF TONGUE

FAILURE OF DESCENT of the THYROID ANLAGE

Answer 2

Lingual Thyroid

exogenous thyroid hormone - suppress TSH
RAI ablation then hormone replacement

Question 3

Normal thyroid tissue found in the other compartments of the neck

Answer 3

Ectopic Thyroid

Question 4

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

Answer 4

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

Question 5

Staging of the Neck

Answer 5

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

Question 6

removes levels I to V cervical lymphatics, spinal accessory nerve, IJV and SCM

Answer 6

Radical Neck Dissection

Question 7

Removes the SAME levels of cervical lymphatics as in RND BUT PRESERVES the spinal accessory nerve, IJV, SCM

Answer 7

Modified Radical Neck Dissection (Functional Neck Dissection)

Question 8

Preserves lymphatic structures normally removed in an RND or MRND

Answer 8

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

Question 9

MC benign salivary gland tumor

Answer 9

Pleomorphic adenoma

Question 10

MC malignant salivary gland tumor

Answer 10

Mucoepidermoid Ca

Adult - 2nd MC -adenoid cystic ca - w/ propensity for
distant mets

Children - 2nd MC - acinic cell ca

Question 11

Most important use if for monitoring of differentiated thyroid cancer recurrence after total thyroidectomy and RAI ablation

Answer 11

Serum Thyroglobulin

Question 12

Sensitive marker for medullary thyroid cancer

Answer 12

Serum Calcitonin

Question 13

LOW dose radiation (12-24 hrs half life)

for imaging thyroid tissues - lingual, ectopic metastatic

Answer 13

Iodine 123

Question 14

HIGHER radiation - 8-10 days half life)

screen and treat differentiated thyroid cancers - papillary and follicular ca

Answer 14

Iodine 131

Question 15

WHO Classification of Thyroid Size

Answer 15

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

Question 16

Some Indications for THYROIDECTOMY

Answer 16

confirmed cancer or suspicious thyroid nodules
severe reactions to antithyroid medications
large goiters w/ compressive symptoms
reluctant to undergo RAI

Question 17

Initial test that must be requested in the evaluation of thyroid nodules

Answer 17

Serum TSH

if euthyroid or hypothyroid — FNAB
if hyperthyroid — RAI scan

Question 18

For detecting NON PALPABLE thyroid nodules, differentiating SOLID vs CYSTIC and identifying CERVICAL LYMPHADENOPATHIES

Answer 18

Thyroid Ultrasound

Question 19

Most useful for LARGE, FIXED, SUBSTERNAL goiters and evaluation of LUNG METASTASES

Answer 19

CT Scan

Question 20

For evaluation of EXTRATHYROIDAL TUMOR EXTENSION - hoarsenss, dysphagia, stridor, cough

Answer 20

MRI

Question 21

Provides anatomic and physiologic information

Answer 21

Iodine Scan

hot or warm lesion - increased activity (< 5 % risk of malignancy)
cold lesion - traps less iodine than surrounding gland (20 % risk of malignancy)

Question 22

Used to screen malignancies when other imaging studies are negative

Answer 22

Positron Emission Tomogram (PET) scan

Question 23

Single most important test in evaluation of thyroid nodules

Answer 23

Fine Needle Aspiration Biopsy (FNAB)

at least 6 follicles w/ at least 10-15 cells from at least 2 aspirates

Question 24

Features suggesting MALIGNANCY in a THYROID NODULE

Answer 24

Ultrasound of the Thyroid

hypoechogenecity
microcalcifications
irregular or blurred nodule margins
increased nodular blood flow
evidence of tumor invasion or regional lymph node metastases

Question 25

Features suggesting MALIGNANCY in a CERVICAL LYMPH NODE

Answer 25

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 ```

Question 26

MC thyroid cancer

Answer 26

Papillary carcinoma prior history of EXTERNAL RADIATIONS Orphan Annie Nuclei Psammoma bodies cervical lymph nodes - site of metastasis

Question 27

Treatment for Papillary Carcinoma

Answer 27

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

Question 28

Usually solitary and encapsulated lesions

Answer 28

Follicular carcinoma iodine deficient areas cervical lymphadenopathy - uncommon CANNOT be diagnosed by FNAB (+) vascular and capsular invasion

Question 29

Treatment for follicular neoplasm

Answer 29

Adenoma - thyroid lobectomy | Carcinoma - total thyroidectomy

Question 30

Subtype of follicular carcinoma | multifocal and bilateral

Answer 30

Hurtle Cell Carcinoma from OXYPHIL cells neck - common metastatic area

Question 31

Arises from PARAFOLLICULAR cells at the SUPEROLATERAL lobes of thyroid gland

Answer 31

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

Question 32

Treatment for Medullary Carcinoma

Answer 32

Total Thyroidectomy w/ Bilateral Central Neck Node Dissection

Question 33

1 % o all thyroid malignancies; HIGHLY AGGRESSIVE tumor

Answer 33

Anaplastic carcinoma giant and multinucleated cell - FNAB lymph node metastases

Question 34

Treatment for Anaplastic Carcinoma

Answer 34

mostly palliative TT or NTT En Bloc resection if w/ extrathyroidal extension adjuvant radiotherapy w/ or w/o chemotherapy

Question 35

Postoperative Complications w/n 24 hrs of Thyroid Surgery

Answer 35

Hypocalcemia Dyspnea Dystonia

Question 36

MC malignancy that metastasize to thyroid

Answer 36

Renal Carcinoma

Question 37

Salivary Gland Tumors Risk of Malignancy

Answer 37

Sublingual - 100% Submandibular - 50% Parotid - 20%

Question 38

75% of all salivary gland tumors occur in

Answer 38

Parotid Gland

Question 39

MC location of SUPERNUMERARY GLANDS

Answer 39

Thymus ``` OTHER LOCATIONS: w/n the parenchyma of thyroid glands tracheoesophageal groove mediastinum anywhere along the neck ```

Question 40

MC location of ECTOPIC PARATHYROID

Answer 40

Paraesophageal

Question 41

Increased PTH from abnormal parathyroid glands Etiology: parathyroid adenoma parathyroid hyperplasia parathyroid carcinoma

Answer 41

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

Question 42

Treatment for Primary Hyperparathyroidism

Answer 42

Parathyroidectomy

Question 43

Increased PTH in response to hypocalcemic states (chronic renal failure, inadequate calcium intake, gut malabsorption)

Answer 43

Secondary Hyperparathyroidism Calciphylaxis - painful violaceous lesions on the extremities that may necrose and become gangrenous leading sepsis and death

Question 44

Treatment for Secondary Hyperparathyroidism

Answer 44

Phosphate binding antacids Cinacalcet (calcimimetic) Oral calcium and vitamin D for uncontrolled symptoms - 3.5 parathyroidectomy or total parathyroidectomy + autotransplantation

Question 45

Persistent hyperparathyroidism and hypercalcemia following successful renal transplant or resolution of underlying

Answer 45

Tertiary Hyperparathyroidism d.t. irreversible parathyroid gland hyperplasia w/ autonomous PTH production

Question 46

MCC is thyroid surgery | DiGeorge syndrome - congenital absence of parathyroid gland

Answer 46

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)

Question 47

Treatment for Hypoparathyroidism

Answer 47

Calcium (IV gluconate) | Vitamin D supplementation