# Case report: From metabolic instability to remission: a case of pheochromocytoma presenting as atypical diabetes

## TL;DR

A woman with atypical diabetes symptoms was found to have pheochromocytoma, a tumor causing severe metabolic instability, and her diabetes resolved after surgery.

## Contribution

This case highlights pheochromocytoma as a rare but treatable cause of atypical diabetes with metabolic instability.

## Key findings

- Pheochromocytoma can cause severe, reversible diabetes with glycemic instability and β-cell dysfunction.
- Surgical removal of the tumor led to diabetes remission and normalized blood pressure.
- Paroxysmal symptoms and labile diabetes should prompt consideration of pheochromocytoma in the differential diagnosis.

## Abstract

Pheochromocytoma is a well-established cause of secondary hypertension and can lead to dysglycemia. However, its initial presentation as atypical diabetes, characterized by severe glycemic instability, is uncommon and poses a significant diagnostic challenge.

A 49-year-old non-obese Chinese woman presented with a 15-month history of progressive polyuria and polydipsia. Initially diagnosed with type 2 diabetes, she developed significant glycemic variability with recurrent hypoglycemia and profound hyperglycemia, alongside a rapid decline in β-cell function. During hospitalization, paroxysmal hypertension was observed. Biochemical testing confirmed markedly elevated catecholamines and metabolites. Imaging identified a left adrenal mass, confirmed as pheochromocytoma following laparoscopic adrenalectomy. Postoperatively, all antidiabetic medications were discontinued. At 3-month follow-up, she achieved sustained normoglycemia with restored β-cell function and normalized blood pressure.

This case demonstrates that pheochromocytoma can induce a severe, reversible form of diabetes characterized by profound metabolic instability and marked glycemic variability. It highlights the necessity of including pheochromocytoma in the differential diagnosis of patients with atypical, labile diabetes, especially when paroxysmal symptoms are present. Early surgical intervention can reverse these metabolic derangements, often leading to diabetes remission.