[Lipoma of the medulla oblongata--an autopsy case report].

An autopsy case of a 34-year-old female with an intracranial lipoma at the lowerst portion of the cerebellomedullary cistern is reported. Intracranial limpomas are rare and to date, only a few autopsy cases have been reported in Japan. A tumor portion, externally protruding from the medulla oblongata was mainly composed of adult adipose tissue; there were many onion-bulbs, consisting of Schwann-like cells, in the parenchyma of the medulla oblongata which was almost completely replaced with tumor tissue. The tumor appeared to be derived from primitive meninx which may have differentiated into adult fat cells. The intracranial lipoma was considered to be a hamartomatous tumor.