Desmoid tumors are rare, benign tumors with locally aggressive behavior which originate from
fascial or musculoaponeurotic structure. They are more common in young women than young man. The
etiology of desmoid tumors are uncertain but may be related to operation, trauma or hormonal factors. The
authors report a 17-year old woman, gravida 1, para 1 with a mass at her lower abdominal wall during the
fifth month of gestation. She was biopsied during delivery in another hospital but was not given a definite
diagnosis. The mass had grown rapidly after biopsy and delivery. The tumor measured 28 x 21 x 18 centimeters
in size and 4,900 g in weight. Complete surgical excision was performed. The pathological report was desmoid
tumor (aggressive fibromatosis). She had no post-operative complication and no recurrent tumor in the 8
months after operation.

Keywords: Abdominal wall, Fibromatosis, abdominal, Fibromatosis, aggressive, Pregnancy complications,
neoplastic