WBR0446

Author	[[PageAuthor::Serge Korjian M.D. (Reviewed by Will Gibson) (Reviewed by Alison Leibowitz) (Reviewed by Serge Korjian)]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Pathology
Sub Category	SubCategory::Endocrine
Prompt	[[Prompt::A 45-year-old woman presents to the physician’s office with complaints of severe diarrhea of several days duration. The patient’s medical history is significant for recurrent kidney stones and a parathyroidectomy 8 years ago. Her fasting gastrin level is elevated and endoscopy reveals multiple ulcers in the stomach, duodenum, and jejunum. Which of the following findings is most frequently associated with this patient's condition?]]
Answer A	AnswerA::Oral ganglioneuroma
Answer A Explanation	AnswerAExp::Oral ganglioneuromatosis frequently occurs in patients with MEN2B syndrome.
Answer B	AnswerB::Pheochromocytoma
Answer B Explanation	AnswerBExp::Pheochromocytoma frequently occurs in MEN 2A and MEN 2B syndromes.
Answer C	AnswerC::Medullary thyroid cancer
Answer C Explanation	AnswerCExp::Medullary thyroid cancer frequently occurs in MEN 2A and MEN 2B syndromes.
Answer D	AnswerD::Prolactinoma
Answer D Explanation	[[AnswerDExp::Prolactinoma, a pituitary tumor, frequently occurs in MEN I syndrome. Prolactin causes an increase in dopamine release from the arcuate nucleus of the hypothalamus and thereby inhibits pituitary release of GnRH. A decrease in GnRH causes a decrease in LH and FSH, and consequently decreases sex hormone concentrations in the blood. Because of this cascade, decreased libido is one of the most prominent symptoms of a prolactinoma.]]
Answer E	AnswerE::Carcinoid tumor
Answer E Explanation	AnswerEExp::Carcinoid tumor is an endocrine tumor, but is not frequently associated with MEN syndrome.
Right Answer	RightAnswer::D
Explanation	[[Explanation::The patient in this vignette most likely has multiple endocrine neoplasia type I (MEN 1). We know from the patient's past medical history that she likely had a parathyroid adenoma. Parathyroid adenomas can secrete PTH and thereby increase serum calcium and decrease serum potassium. Increased serum calcium can be lead to elevated calcium passing into the urine, thereby increasing the risk of calcium oxalate kidney stones. The definitive treatment of these tumors is surgical removal (parathyroidectomy) as in this patient. The patient now presents with symptoms highly consistent with a gastrinoma. These are gastrin-secreting tumors that form in either the pancreas or the duodenum. Recall that gastrin is a peptide hormone that stimulated parietal cells to increase secretion of gastric acid. Patients with gastrinomas therefore frequently develop multiple ulcers due to excessive gastric acid production in the stomach. Nearly 25% of gastrinoma patients have MEN 1. A patient with who has developed both parathyroid adenoma and gastrinoma is certainly affected by MEN 1. MEN I syndrome is characterized by parathyroid tumors, pituitary tumors, and pancreatic endocrine tumors. Remember the three P's of MEN 1! Several subtypes of pancreatic endocrine tumors are associated with MEN1, including gastrinoma, insulinoma, VIPoma, or glucagonoma. All of the MEN syndromes are dominantly inherited genetic disorders. MEN1 syndrome is caused by mutations in the MEN1 gene that ecodes the tumor suppressor menin. A good way to remember which organ systems are affected by the different MEN syndromes is: MEN I (3 Ps) - Pituitary, Parathyroid, Pancreatic MEN IIa (1M,2Ps) - Medullary Thyroid Ca, Pheochromocytoma, Parathyroid MEN IIb (2Ms,1P) - Medullary Thyroid Ca, Marfanoid habitus/mucosal neuroma, Pheochromocytoma Educational Objective: MEN I syndrome often manifests with pituitary tumors, parathyroid tumors, or pancreatic endocrine tumors. References: Thakker, R. V., Newey, P. J., Walls, G. V., Bilezikian, J., Dralle, H., Ebeling, P. R., ... & Brandi, M. L. (2012). Clinical practice guidelines for multiple endocrine neoplasia type 1 (MEN1). The Journal of Clinical Endocrinology & Metabolism, 97(9), 2990-3011. Basuroy R, Srirajaskanthan R, Prachalias A, Quaglia A, Ramage JK. Review article: the investigation and management of gastric neuroendocrine tumours. Aliment Pharmacol Ther. May 2014;39(10):1071-84. First Aid 2014 page 329 First Aid 2015 page 337]]
Approved	Approved::Yes
Keyword	WBRKeyword::Prolactinoma, WBRKeyword::Pheochromocytoma, WBRKeyword::Gastrinoma, WBRKeyword::Neoplasia, WBRKeyword::MEN I, WBRKeyword::Cancer, WBRKeyword::Wermer syndrome, WBRKeyword::Diarrhea, WBRKeyword::Ulcers, WBRKeyword::Gastrinoma, WBRKeyword::Tumor, WBRKeyword::Pancreatic cancer, WBRKeyword::Multiple endocrine neoplasia
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