Deeply seated aggressive fibromatosis also termed as desmoid tumors are rare tumors that invade surrounding structures. Although they never metastasize mortality rate may be as high as 10% due to their aggressive local behavior. Intraabdominal desmoid tumors are usually associated with familial poliposis coli and have a high recurrence rate regardless of the therapy instituted. Sporadic cases are very rare and generous surgical excision may be of benefit. We hereby report 2 siblings with sporadic pancreatic desmoid tumors who also harbor additional fibrotic masses in the pelvis. Although in previously reported cases there is usually a triggering event such as trauma, in the present cases there was no inciting event. Furthermore, the cases are without an associated FAP history, which provides the first clinical clue of a possible genetic determinant in this rare disorder.