Tumor of endocrine system

Question 1

What are pituitary adenomas and how are they classified?

Answer 1

Pituitary adenomas are benign tumors of the pituitary gland, making up 8-10% of intracranial tumors.
They are classified based on their size:
-microadenomas are less than 1 cm in diameter, -macroadenomas are more than 1 cm,
-giant adenomas, such as prolactinomas, are larger than 4 cm​

Question 2

What are the clinical features associated with pituitary adenomas?

Answer 2

mass effect symptoms such as non-specific headaches, visual disturbances (like bitemporal hemianopia), and cranial nerve palsies (involving nerves VI, V2, III, IV, VI) due to compression of the cavernous sinus​

Question 3

What investigations are used to diagnose pituitary adenomas?

Answer 3

-Blood tests for hormones potentially affected by the tumor, including serum prolactin, insulin-like growth factor, plasma ACTH, LH & FSH, and TSH.
-A 24-hour urine cortisol test.
-Imaging, such as high-resolution CT and MRI scans, with MRI being the gold standard for detecting microadenomas

Question 4

What clues can indicate the nature of a thyroid nodule?

Answer 4

-Solitary nodules are more likely neoplastic, while multiple nodules are less likely.
-Nodules in patients younger than 20 or older than 70 are more likely neoplastic.
-Incidence of thyroid cancers is higher in females, but nodules in males are more likely neoplastic.
-History of radiation exposure increases the risk.
Iodine uptake studies: “Hot” nodules (increased uptake) are typically benign, whereas “cold” nodules (decreased or no uptake) raise higher concerns for malignancy​

Question 5

What are the clinical features of follicular adenoma of the thyroid?

Answer 5

Follicular adenoma of the thyroid typically presents as a solitary nodule. It is usually non-functional and not associated with hyperthyroidism​

Question 6

What are the characteristics of papillary carcinoma of the thyroid?

Answer 6

-Papillary carcinoma is the most common thyroid malignancy and is often associated with exposure to ionizing radiation.

• It spreads primarily through lymphatic metastasis, commonly to cervical lymph nodes, and can also spread hematogenously to the lungs.
• It is slow-growing and has a good prognosis, with a 10-year survival rate of 95%.

-Clinically, it presents as a painless solitary thyroid mass and may cause cervical lymph node enlargement.

-Characteristic features include papillary structures, clear nuclei (orphan Annie eye), and psammoma bodies (small, round, calcified deposits)​

Question 7

What distinguishes follicular carcinoma of the thyroid?

Answer 7

-Follicular carcinoma accounts for 5-15% of thyroid cancers and is more common in females, often due to iodine deficiency.

• It typically presents as a solitary thyroid nodule, is mostly non-functional, but may rarely be hyperfunctional.

-It spreads hematogenously and may exhibit capsule breach with neoplastic cell invasion into vascular structures​

Question 8

What are the features of anaplastic carcinoma of the thyroid?

Answer 8

-Anaplastic carcinoma is an undifferentiated and aggressive thyroid tumor, comprising less than 5% of thyroid cancers.

-It generally occurs in patients older than 65 and often invades adjacent structures.

-It may arise from pre-existing follicular or papillary carcinomas

Question 9

What are the characteristics of medullary carcinoma of the thyroid?

Answer 9

-Medullary carcinoma arises from C cells and can secrete calcitonin, serotonin, VIP, and somatostatin.

-It may be associated with multiple endocrine neoplasia (MEN) syndromes.

-Clinical features include a neck mass with or without compression symptoms and symptoms related to hormone secretion, particularly calcitonin

Question 10

What is pheochromocytoma and what are its clinical features?

Answer 10

-Pheochromocytoma is a tumor of chromaffin cells in the adrenal medulla that synthesizes catecholamines.

-It follows the “Rule of 10s” (10% are bilateral, in children, metastasize, calcify, and extra-adrenal). It may be part of inherited syndromes like MEN 2A and 2B, Von-Hippel-Lindau, and Neurofibromatosis type 1.

-Symptoms include hypertension, sweating, anxiety, palpitations, tachycardia, headaches, and polycythemia​

Question 11

What are the diagnostic investigations and treatment options for pheochromocytoma?

Answer 11

Diagnostic investigations for pheochromocytoma include CT or MRI scans to confirm a suprarenal mass, and lab tests for urinary and serum catecholamine breakdown products (HMA, VMA) and CBC for polycythemia.

Treatment typically involves surgery and control of hypertension​