Lack of symptoms in patients with histologic evidence of pheochromocytoma: a diagnostic challenge.

Pheochromocytoma (Pheo) is a rare cause of hypertension (HTN). Classically, a triad of symptoms includes sweating, palpitations, and headache. HTN is often present and labile. Although a triad of symptoms is cited as the most frequent presenting complaints, our clinical experience leads us to question how often these are present. Thirty-two patients with histologically proven pheo or paraganglionoma were evaluated. Around 84.4% patients had adrenal pheos and 15.6% had extra-adrenal pheos. Two patients had bilateral adrenal tumors, two had a history of prior pheos, and four had a family history of pheo. There were 19 (59.4%) female and 13 (40.6%) male patients. Six (18.7%) patients were black and 26 (81.3%) were white. The mean age at presentation was 43.2+/-13.9 years. Two patients were known to have neurofibromatosis type 1, two had von Hippel-Lindau disease, one had multiple endocrine neoplasia 2A, and one PGL/SDHD genetic mutation. Twenty-six patients had sporadic tumors or had not had genetic testing. Biochemical diagnosis was confirmed with 24-h urine measurements. Urine catecholamine measurements were elevated at least 2 to 4 times above normal levels. Mean SBP readings at presentation were 128+/-19 mmHg. Mean DBP readings were 81+/-13 mmHg. Around 65.6% patients were hypertensive at presentation. Fifty percent of the patients had palpitations, 40.6% had tachycardia, 34.4% had sweating, and 31.3% had headaches. Initial presenting symptoms were diverse. Pheo is a rare clinical entity and remains a huge diagnostic challenge for all clinicians.