Endocrine Abstracts

A 44 year old man attended our endoscopy unit for gastroscopy to further investigate ongoing epigastric pain. He was incidentally found to be very hypertensive so gastroscopy was cancelled. Hypertension was treated. He had past medical history of hypertension and Gout. Routein blood tests showed renal impairment with significantly raised calcium 3.19 mmol/l. Hypercalcemia was treated with iv bisphosphonates. MEN 2a, was considered as a unifying diagnosis for high calcium and hypertension. Further work up showed normal PTH, vitamin D, alkaline phosphate and auto antibody screening. 24 hour urinary calcium excretion and urinary calcium to creatinine ratio was normal. PTHrP was undetectable. Thyroid functions and cortisol were in normal range. Urine and plasma catecholamines were normal. Provisional diagnosis of MEN2a was discarded due to negative endocrine work up. Serum and urine protein electrophoresis, bone turnover markers like P1NP and plasma CTX were also in normal range. Serum phosphate was intermittently raised. Although there were no symptoms but serum ACE level was done and were found to be high normal, 55 iu/l (15–55 iu/l). Repeat ACE level was normal and CT TAP did not show any abnormality. HRCT thorax was further performed which excluded any interstitial/granulomatous lung disease. FDG PET showed high intensity FDG activity within gastric pylorus. Gastroscopy showed reactive gastritis.Later on 1–25 dihydroxy vitamin D was checked and was found to be significantly high, 196 pmol/l (5–55 pmol/l). Patient was not on any sort of vit D preparation. Radiological work up was negative for any malignancy and granulomatous disorder which could produce 1–25 hydroxy vitamin D. Finally the reason for hypercalcemia was considered to be due to CYP24 A1 mutation. This rare disorder is due to inactivation mutation in CYP24 A1 gene. This leads to production of a defective 24 hydroxylase enzyme which is responsible for degradation of 1–25 hydroxy vitamin D. Patients with this mutation can present with any symptoms associated with hypercalcemia but additional feature of severe hypertension has been described. PTH and 25 hydroxy vitamin D are usually normal. 24–25 dihydroxy vitamin D level is usually low and finally diagnosis can be confirmed with genetic testing. Our patient is awaiting genetic testing. Longterm treatment of hypercalcemia with condition is considered with glucocorticoid or azole, antifungal medications. Our patient is currently on glucocorticoid and we plan to switch him to antifungals after confirmation of diagnosis with genetic testing.