# Beyond Hypertension: Hypoglycemia as an Atypical Presentation of Pheochromocytoma in Neurofibromatosis Type 1

## TL;DR

A rare case of pheochromocytoma in a patient with neurofibromatosis type 1 presented with hypoglycemia instead of the usual high blood pressure.

## Contribution

This case highlights hypoglycemia as an atypical initial presentation of pheochromocytoma in neurofibromatosis type 1.

## Key findings

- A 27-year-old woman with NF1 presented with hypoglycemia and was diagnosed with pheochromocytoma.
- Biochemical tests confirmed elevated metanephrines and normetanephrine levels.
- The case suggests hypoglycemia can be an initial sign of hereditary pheochromocytoma in NF1.

## Abstract

Pheochromocytoma is a rare adrenal tumor characterized by catecholamine hypersecretion. It can occur sporadically or as part of hereditary disorders, such as multiple endocrine neoplasia type 2 (MEN2) and, less commonly, neurofibromatosis type 1 (NF1). Pheochromocytoma can cause metabolic disturbances, including impaired glucose tolerance and hyperglycemia. However, hypoglycemia is typically a postoperative complication rather than an initial presentation. We reported an unusual presentation of pheochromocytoma with persistent hypoglycemia in a patient with NF1. A 27-year-old normotensive woman with a past medical history of NF1 experienced a sudden episode of dizziness and presyncope while she was driving, causing a motor vehicle accident. She was found with persistent hypoglycemia, and her imaging revealed a right adrenal mass. The diagnosis of pheochromocytoma was confirmed through biochemical testing, which revealed significantly elevated serum metanephrines and normetanephrine levels. Our case shows that hereditary pheochromocytoma associated with NF1 can present with persistent hypoglycemia.