Hibernoma: a case report and discussion of a rare tumor

Intriduction. Hibernomas account for less than 2 % of all benign lipomatous tumors and 1 % of all lipomatous tumors. They are usually found in 20–40-year old adults (the average age of patients is 38 years). The clinical manifestations are painless soft tissue mass that are mostly slow growing; rapid growth is only found in a small number of patients. We present a case of successful surgical treatment of a pathologically confirmed rare lipomatous tumor of large size, which was located in the soft tissues of the thigh.

Clinical case. A 46-year-old woman was admitted to the hospital due to a tumor 20 × 10 × 10 cm in size, that had developed 10 years ago in the anteromedial aspect of the proximal thigh. Furthermore, she had a history of hypoesthesia one month prior to her admission. During surgery, the femoral nerve was found to be compressed by the large tumor. The resultant symptoms probably caused the patient to seek medical care. Resection was performed by careful dissection, femoral nerve and vessels were spared. Histopathological examination and cytogenetics showed findings suggestive of a hibernoma. At the 6-month follow-up local tumor recurrence or metastasis was not found.

Conclusions. Asymptomatic small-sized hibernoma does not require surgical resection or other treatment. When the tumor is too large and/or has the potential to compress the surrounding tissues, timely radical surgical intervention is reuired.

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