Medicine>>>>>Endocrinology and Metabolic Disease
Question 2#

A 24-year-old white man presents with a persistent headache for the past few months. The headache has been gradually worsening and is unresponsive to over-thecounter medicines. He notices diminished peripheral vision while driving. He takes no medications. He denies illicit drug use but has smoked one pack of cigarettes per day since the age of 18. Past history is significant for passage of a kidney stone last year. At that time, he was told to increase his fluid intake. Family history is positive for diabetes in his mother. His brother (age 20) has had kidney stones from too much calcium and a “low-sugar problem.” His father died of some type of tumor at age 40. Physical examination reveals a deficit in temporal fields of vision and a few subcutaneous lipomas.

Laboratory results are as follows:

• Calcium: 11.8 mg/dL (normal 8.5-10.5)
• Cr: 1.1 mg/dL
• BUN: 17 mg/dL
• Glucose: 70 mg/dL
• Prolactin: 220 µg/L (normal 0-20)
• Intact parathormone: 90 pg/mL (normal 8-51)

You suspect a pituitary tumor and order an MRI which reveals a 0.7-cm pituitary mass. Based on this patient’s presentation, which of the following is the most probable diagnosis? 

A. Tension headache
B. Multiple endocrine neoplasia type 1 (MEN1)
C. Primary hyperparathyroidism
D. Multiple endocrine neoplasia type 2A (MEN2A)
E. Prolactinoma

Correct Answer is B

Comment:

 This young man presents with two obvious serum abnormalities—hypercalcemia and hyperprolactinemia (most likely secondary to the pituitary tumor). This, along with his positive family history of a younger sibling with high calcium and low blood sugar and a father who died from an unknown tumor, indicates this family has one of the multiple endocrine neoplasia syndromes. MEN1 is associated with hyperparathyroidism, pituitary tumors (usually prolactinomas), and islet cell tumors (most commonly gastrinomas, occasionally insulinomas). This patient’s personal and family history, therefore, suggests MEN1. The MEN2 syndromes include medullary carcinoma of the thyroid and pheochromocytoma. MEN2A is associated with hyperparathyroidism; MEN2B with mucosal and GI tract neuromas. There is no pituitary abnormality with the MEN2 syndromes. It would not be prudent to treat the patient’s issues as two separate abnormalities (primary hyperparathyroidism and prolactinoma). Tension headache is untenable in the face of a pituitary tumor and visual field deficit.