Abstract
A 48-year-old man was found to have a 6-cm mass in the right abdomen near the kidney on abdominal ultrasound during a routine medical examination. He was referred to our hospital for further evaluation. Abdominal contrast CT showed a 6-cm, well-defined, tumor-like lesion with uniform contrast adjacent to the transverse abdominis muscle (TAM). Abdominal MRI with T1-weighted fat-suppression imaging showed uniformly low signal intensity. A barium enema showed extrinsic compression of the hepatic flexure and transverse colon.
These findings suggested a lipoma of the TAM, but surgery was planned because a malignant tumor could not be ruled out. Imaging showed protrusion into the abdominal cavity, and laparoscopic surgery was performed. A mass protruding below the right costal arch without invasion into surrounding organs was seen. Resection of the mass with part of the peritoneum, preperitoneal fat, and the TAM was performed.
Histopathological examination showed proliferation of fatty tissue surrounded by a capsule, little atypia, and adherent TAM around the margins. The diagnosis was an intermuscular lipoma. Laparoscopic resection of an abdominal wall lipoma is rare. This case is reported along with a discussion of the relevant literature.
