A pheochromocytoma presenting as generalized pigmentation

A 25-year-old man presented with pigmentation over the face and hands of 6 months' duration, which darkened on sun exposure. Four weeks after the onset of pigmentation, he experienced intermittent episodes of excessive sweating, tremors, fatiguability, and headache, which had gradually increased in frequency over the last 5 months. There was a history of anorexia and weight loss of 7 kg over the last 6 months. There was no history of previous drug ingestion, chemical exposure, or any major illness. The family history, including diabetes, tuberculosis, hypertension, endocrine tumors, and pigmentation, was negative. On dermatologic examination, slate-gray macular pigmentation was noticed on the forehead, cheeks, nose, lips (Fig. 1), helices of the ears, and dorsum of the hands, with prominence over the knuckles and the skin over the interphalangeal joints, elbows, and knees (Fig. 2). The scars of acne and previous injuries over the legs were also hyperpigmented. The mucosa of the hard palate showed streaky linear pigmentation in the midline. On general examination, tachycardia was a constant feature at all visits, and more marked on the last three visits (104, 100, and 120/min, respectively). Hypertension was noted in the right upper arm in the supine position at two of the last three consultations (140/100, 120/84, and 180/118 mmHg, respectively). A significant orthostatic hypotension was noted on standing during the last visit, i.e. 150/110 mmHg. The following laboratory investigations were performed: hemoglobin (Hb), 11.7 g%; erythrocyte sedimentation rate (ESR), 30 mm in the first hour; serum cortisol, 26.8 mg/dL (N < 14 mg/dL, PM sample); serum adrenocorticotrophic hormone (ACTH), 101 pg/mL (N < 60 pg/mL); urinary vanillylmandelic acid (VMA), 16.3 mg in 24 h (N < 9 mg/24 h). The following were all within normal limits: complete blood count (CBC), blood sugar, urinalysis, serum electrolytes, calcium, B-12 levels, thyroid and liver function tests, and stool (routine and occult blood) test. Chest X-ray, thyroid scan, and ultrasonography were normal. Human immunodeficiency virus (HIV) was nonreactive. Abdominal sonography revealed a hypoechoic and well-circumscribed mass in the left suprarenal area. Computed tomography of the abdomen confirmed a tumor location in the left adrenal gland with mild enhancement after contrast (Fig. 3). The patient was operated on to remove a mass measuring 5 cm x 3.5 cm x 3.2 cm. Histopathology of the tissue confirmed a diagnosis of pheochromocytoma. To our surprise, the pigmentation faded rapidly in the immediate postoperative period and the scar at the operation site did not pigment significantly (Fig. 4).