27. ADRENAL ONCOCYTIC PHEOCHROMOCYTOMA WITH PROBABLE MALIGNANT POTENTIAL: A UNIQUE CASE REPORT. (February 2015)

• Record Type: Journal Article
• Authors: Kasem, Kais; Lam, Alfred
• Is Part Of: Pathology. Volume 47(2015)Supplement 1
• Publication Date: 2015-02
• Subjects: Pathology -- Periodicals; 616.0705
• DOI: 10.1097/01.PAT.0000461636.12665.15
• Languages: English
• ISSNs: 0031-3025

Abstract

Abstract : Oncocytic pheochromocytomas are exceedingly rare tumours. To date, there are 3 reported cases in the literature. We present a case of a 68-year-old man with moderate hypertension and an incidental adrenal mass on radiological investigations. The patient had normal levels of 24-hour urine cortisol, metanephrines and non-metanephrines. The tumour was subsequently excised. Macroscopic examination revealed a light brown, 45 × 35 × 35 mm, 36 g tumour of the adrenal gland. Histologically, the tumour cells showed oncocytic appearance with high-grade nuclear abnormalities and foci of extension into the peri-adrenal fat. Immunohistochemical studies revealed that the tumour was positive for chromogranin, S-100 and p53 and negative for inhibin, HMB-45 and EMA. The malignant potential of pheochromocytoma is known to be difficult to predict. Two scoring systems were used; PASS (phaeochromocytoma of adrenal scaled score) by Thompson and a Japanese scoring system by Kimura and colleagues. Both scoring systems predicted the tumour had a malignant potential. However, no recurrence was detected after 5 years of follow-up. In summary, this is the first reported case of oncocytic pheochromocytoma with probable malignant potential.