WBR0446
| Author | [[PageAuthor::Yazan Daaboul, 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. |
| 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). From the patient's past history of parathyroidectomy, it is highly likely that she had a parathyroid adenoma. Parathyroid adenomas classically secrete excessive PTH leading to elevated serum calcium and decreased serum phosphate levels. The increased serum calcium also leads to excess urinary excretion, increasing the risk of calcium oxalate kidney stones. The current presentation is highly consistent with a gastrinoma, a gastrin-secreting tumor that arises from tissues of either the pancreas or the duodenal wall. Gastrin is a peptide hormone that stimulates parietal cells to increase gastric acid secretion. 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 who has developed both parathyroid adenoma and gastrinoma is highly likely to be affected by MEN 1. MEN I syndrome is characterized by parathyroid tumors, pituitary tumors, and pancreatic endocrine tumors. Several subtypes of pancreatic endocrine tumors are associated with MEN 1, 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 |
| 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 |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |