Unusual Presentation of Pheochromocytoma with Ischemic Sigmoid Colitis and Stenosis:

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.

Is the excess cardiovascular morbidity in pheochromocytoma related to blood pressure or to catecholamines?

BACKGROUND

It is generally accepted that pheochromocytoma is associated with an increased cardiovascular risk. This is however not based on studies with an appropriate control group of patients with essential hypertension.

AIM OF THE STUDY

We examined whether patients with pheochromocytoma have an excess cardiovascular morbidity as compared to hypertensive patients.

METHODS

In a retrospective case-control study we reviewed the medical charts of 109 pheochromocytoma patients for cardiovascular events within 5 years prior to the diagnosis. These patients were matched to control patients with essential hypertension for gender and year of birth and diagnosis. Outcome variables were ischemic heart disease, cerebrovascular accidents, and transient ischemic attacks. Classical cardiovascular risk factors were also assessed.

RESULTS

A significantly higher rate of patients with pheochromocytoma suffered a cardiovascular event (13.8%; 95% confidence interval: 7.9%-21.6%) as compared to hypertensive patients (1.1%, 95% confidence interval: 0.1%-3.9%) (P < .001). Blood pressure level was lower in pheochromocytoma patients (153/91 ± 35/15 mm Hg) than in hypertensive patients (170/103 ± 18/8 mm Hg) (P < .001), even after correction for use of antihypertensive medication (P < .02). The difference in event rates could not be attributed to differences in other cardiovascular risk factors.

CONCLUSIONS

Pheochromocytoma patients have a clearly higher rate of cardiovascular events than patients with essential hypertension. This cannot be attributed to differences in blood pressure or other cardiovascular risk factors. The most likely explanation for the excess event rate is the prolonged exposure to the toxic effects of tumoral catecholamines. These data underpin the importance of a timely diagnosis and treatment of pheochromocytoma.