Rare Cases of Hibernomas Associated With Bilateral Pheochromocytoma: A Report of Two Cases

Hibernoma is an infrequent benign lipomatous tumor that shows differentiation to brown fat. It is a slowly growing tumor of variable consistency but often firmer than a classic lipoma, mobile, and rarely infiltrating. To date, there are only a few cases of adrenal hibernoma in the literature. Herein, we report two cases. The first one is that of a 24-year-old female presenting with a bilateral adrenal incidentaloma discovered in the setting of abdominal pain whose histological study individualized a bilateral pheochromocytoma associated with a hibernoma. The second case is that of a young male of 23 years old. He was operated on in adolescence (age 14) for a left pheochromocytoma. The outcome was marked by the recurrence of the Menards triad ("headache, palpitations, and sweating") and hypertension at the age of 23 years. It was due to the appearance of a contralateral right pheochromocytoma, whose histological study showed an association with a hibernoma, and the genetic study revealed Von Hippel-Lindau (VHL) disease.