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

## TL;DR

A rare case of sarcoidosis causing high blood calcium levels in a patient with a genetic disorder called MEN2A is reported.

## Contribution

This case highlights the rare co-occurrence of sarcoidosis and MEN2A, emphasizing the need for broad differential diagnosis in such patients.

## Key findings

- A patient with MEN2A and the RET C609Y mutation developed sarcoidosis-induced hypercalcemia.
- Liver biopsy confirmed noncaseating granulomas, supporting sarcoidosis diagnosis.
- Treatment with calcitonin, prednisone, and hydroxychloroquine normalized calcium levels.

## Abstract

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.

A 59-year-old female with past medical history of MEN2A, REarranged during Transfection 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. Computed tomography (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 parathyroid hormone: 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 noncaseating granuloma. Positron emission tomography-computed tomography 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 level was 124. Patient was managed acutely with calcitonin and was started on prednisone and hydroxychloroquine. Calcium level normalized.

The co-occurrence of both MEN 2A and sarcoidosis is rare, adding an unexpected layer of complexity to the diagnosis.

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.