Diabetes Mellitus and Cardiomyopathy as Presenting Features of Occult Malignant Pheochromocytoma

The concomitant occurrence of diabetes mellitus and cardiomyopathy secondary to occult malignant pheochromocytoma has rarely been reported. This case report describes the case of a 48-year-old female with a previous history of diabetes mellitus, hypertension, and cardiomyopathy who presented with fatigue and significant weight loss. Neither typical symptoms of pheochromocytoma nor metastatic symptoms were presented. Pheochromocytoma with extension to the liver was incidentally found from computed tomography of the abdomen and laboratory investigations during the work-up to identify the cause for the weight loss. Right adrenalectomy and a right hepatectomy were performed. Malignant pheochromocytoma was diagnosed based on pathology. All of her underlying conditions including diabetes mellitus, hypertension, and cardiomyopathy, were improved following the complete resection of the tumor. This case emphasizes the importance of early suspicion and diagnosis of malignant pheochromocytoma in individuals with atypical presentation of a chromaffin-secreting tumor.