Sarcoidosis-Induced Hypercalcemia in a Patient With Multiple Endocrine Neoplasia Type 2A (MEN2A) Syndrome Harboring the C609Y REarranged During Transfection (RET) Mutation

ABSTRACTBackground/Objective Hypercalcemia is a common clinical manifestation of Multiple Endocrine Neoplasia 2A (MEN 2A) through primary hyperparathyroidism. The objective of this report is to describe a rare and unique case of sarcoidosis-related hypercalcemia in a patient with a history of MEN2A. Case Presentation 59-year-old female with past medical history of MEN2A, RET mutation C609Y, diagnosed in 2007 status post total thyroidectomy presented to the hospital with an acute abdominal pain aggravated with eating. Review of systems was significant for a 40 lbs. weight loss, fatigue, dry mouth and polydipsia. CT abdomen showed liver and spleen nodules, and a few mildly enlarged retroperitoneal lymph nodes. CT chest noted enlarged left axillary lymph nodes but otherwise no enlarged mediastinal lymph nodes. Blood work showed a calcium level of 13.6 8.5-10.3 mg/dl, Intact PTH: 6.3 10-65 pg/mL, 25-OH Vitamin D Level: 21.5 18-50 ng/mL ,1,25-Vitamin D: 51 18-64 pg/mL. Liver biopsy showed non-caseating granuloma. PET-CT showed hypodense splenic nodules, heterogenous liver, diffuse pancreatic atrophy, and lack of abnormal neck/lung adenopathy. The patient was then referred to rheumatology for evaluation for sarcoidosis. Angiotensin-Converting Enzyme (ACE) level was 124. Patient was managed acutely with calcitonin and was stared on prednisone and hydroxychloroquine. Calcium level normalized. Discussion The co-occurrence of both MEN 2A and sarcoidosis is rare, adding an unexpected layer of complexity to the diagnosis. Conclusion The rarity of sarcoidosis co-occurring with MEN 2A highlights the importance of considering a broad differential diagnosis, even in patients with known genetic syndromes, to ensure accurate management.