Disorders of the adrenal medulla

Question 1

Diseases linked to hypofunction

Answer 1

Orthostatic hypertension

Patients receiving glucocorticoid replacement therapy after adrenallectomy

Question 2

Diseases linked to hyperfunction

Answer 2

Pheochromocytoma
Neurocutaneous syndromes
Neuroblastoma

Question 3

Pheochromocytoma General information

Answer 3

A tumor arising from chromaffin cells. Usually benign (10% are malignant - 10% rule: 10% malignant and 10% bilateral). Removable by surgery. Can cause hyperglycemia, anxiety and chest tightness. Most of them occur sporadically but can also be associated with multiple endocrine neoplasia type II (MEN II both a and b). Also associated with von Hippel Lindau disease (which are hemangiomas in the cerebellum).

Question 4

Complications and testing for Pheochromocytoma

Answer 4

Complications: Heart failure, dilated cardiomyopathy arrhythmia

Tests: 3x24 hour urinary collection to check for catecholamines. MRI/CT with administered metaiodobenzylguanidine for detection of extra medullary tumors

Question 5

Neuroblastoma

Answer 5

Highly malignant catecholamine producing tumor (small blue cells) which occurs in childhood. Increases in urinary catecholamines and their metabolites. Leads to hypertension and large abdominal mass. Shows an increase in C-Myc expression.