British Journal of Urology (1997), 80, 679–680

C A S E R E PO R T

Hibernoma in the scrotumH . SAY RAK, E. GON UL* and F. SAYRA K†Departments of Pathology and *Surgery, SSK Goztepe Training Hospital, and †Department of Dermatology, PTT Hospital,Istanbul, Turkey

fat cells; there were no atypical cells or lipoblasts. DuringCase reporta 5-year follow-up, no recurrence was detected; at thelast examination, a subcutaneous lipoma 3 cm in diam-In 1990, a 59-year-old man presented with swelling in

the right scrotum. He had noticed a swelling of about eter was detected above the xiphoid and excised. Thepatient is currently healthy with no further recurrence.0.5 cm in diameter 4 years earlier and had ignored it

because it caused no pain. The swelling had graduallydeveloped into a mass of 5×6 cm. Physical examin- Commentation revealed a subcutaneous tumorous lesion situatedinferiorly and posteriorly in the right scrotum; it was Hibernomas are extremely rare benign lipomatous

tumours of brown-fat origin, seen chiefly in adults.mobile, soft and painless. The right testis, the spermaticcord and the tunica appeared normal. Systemic, radio- Among the 105 cases reported [1], most were located

in areas that normally include brown-fat remnants, e.g.logical and biochemical investigations showed no abnor-malities. The tumorous lesion was considered to be a the scapular and interscapular regions, the chest wall

and the axilla [2]. Brown adipose tissue is prominent inlipoma and the scrotum explored under local anaes-thesia. The tumorous lesion was in the subcutaneous newborn infants, its amount decreasing throughout life,

leaving remnants in the white adipose tissue, especiallyfatty tissue, with no attachment to the tunicae, andwas removed completely. Macroscopically, the material in the neck, axilla and mediastinum [3]. Thus, albeit

very rare, it is likely that a hibernoma can develop inwas soft and circumscribed, light brown, 5×6 cm andenclosed by a thin translucent membrane. In section, it any part of the body, even in a site which is normally

devoid of brown adipose tissue. Two cases of hibernomawas homogeneous with a lobular appearance (Fig. 1).Histological examination showed lobulated aggregates in the spermatic cord and inguinal area, respectively,

have been reported [4,5]; both were deeply located, withof tumour cells with granular or multivacuolated eosino-philic cytoplasm and centrally placed nuclei (Fig. 2). attachment to the tunicae. The hibernoma in the present

case was superficial and is the only case reported inUnivacuolated fat cells were scattered among the brownthe scrotum.

Fig. 1. Gross view of the hibernoma in the scrotum, showing theFig. 2. Granular and multivacuolated eosinophilic brown-fat cellscharacteristic light-brown and lobulated appearance (formalin

fixed). and white-fat cells. Haematoxylin and eosin. ×200.

679© 1997 British Journal of Urology

680 CASE REPOR T

5 El Mezni F, Ammar A, Zermani R, Ben Hassine H, Ben JilaniReferencesS. Inguinal hibernoma. A case report. Ann Pathol 1991;1 Muszynski CA, Robertson D, Goodman JC. Scalp hibernoma:11: 203–4case report and literature review. Surg Neurol 1993;

42: 343–52 Enzinger RM, Weiss SW. Hibernoma. In Stamathis G ed.,

AuthorsSoft Tissue Tumors, 2nd edn. St. Louis: CV Mosby Co,1988: 337–9 H. Sayrak, MD, Pathologist.

E. Gonul, MD, Surgeon.3 Seemayer TA, Knaack J, Wang NS, Ahmet MN. On theultrastructure of hibernoma. Cancer 1975; 36: 1785–93 F. Sayrak, MD, Dermatologist.

Correspondence: Dr H. Sayrak, Ekin Ozel Egitim ve Yabanci4 Fletcher CD, Cole RS, Gower RL, Heyderman E. Hibernomaof the spermatic cord: the first reported case. Br J Urol 1986; Diller, Osmanaga Mah. Nuzhetefendi Sok. No: 36 Ekin Apt.

Kadikoy, Istanbul, Turkey.58: 99–100

© 1997 British Journal of Urology 80, 679–680