Unexpected metastatic pheochromocytoma - an unusual presentation.

The classic triad of pheochromocytoma consists of episodic headache, sweating, and tachycardia. General clinicians should be aware, however, that this rare entity might present with a wide spectrum of clinical symptoms. We recently observed a noteworthy case of malignant pheochromocytoma where there was a lack of specific symptoms despite an advanced tumor stage. Malignancy is an important cause of mortality. Reliable diagnosis of malignancy depends upon evidence of local invasion, distant metastases, or recurrence. As in our case, new scintigraphic methods, such as 111-In-pentetreotide scintigraphy (Octreoscan), may occasionally reveal 123-I-metaiodobenzylguanidine-negative distant metastases and help to establish an early diagnosis of malignancy. Tumor size, and perhaps even biochemical profile, may be factors increasing the likelihood of a malignant process and may contribute to early identification of patients at risk.