Lipomatous ganglioneuroma of the retroperitoneum.

Lipomatous ganglioneuroma (LG) is a rare variant of ganglioneuroma that is histologically characterized by a mature adipocytic component admixed with a conventional ganglioneuroma. We report the clinicopathological and immunohistochemical features of an LG in a 44-year-old Chinese male; additionally, we review the literature regarding this type of tumor. Magnetic resonance imaging revealed a left paravertebral soft-tissue mass at the T11-L3 levels. Grossly, the encapsulated neoplasm had a white to yellowish cut surface and rubbery consistency. Microscopic evaluation revealed an encapsulated lesion that consisted of areas of ganglioneuroma admixed with areas of mature fat. By immunohistochemistry, the ganglion cells were positive for chromogranin and synaptophysin, whereas the Schwann cells were positive for vimentin, S-100 protein, and glial fibrillary acidic protein (GFAP). This is the second known report of a retroperitoneal LG. The patient was well and without evidence of disease at 2 years' follow-up.