Subsequent leiomyoma and intra-abdominal fibromatosis mimicking recurrent gastrointestinal stromal tumor: a case report

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumors of the gastrointestinal tract. In this report, we present a case of GIST patient who had been treated with imatinib, but developed leiomyoma and intra-abdominal fibromatosis (IAF) at the site of GIST resection beds mimicking recurrent GIST. To our knowledge, no patient with the 3 gastrointestinal tumor types we encountered, GISTs, leiomyomas and IAF has ever been reported. Leiomyoma and IAF might be confused with recurrent GIST for similar imaging findings and the overlap in immunophenotypic profiles such as c-Kit, SMA and desmin. The current case highlights the need for careful consideration of leiomyomas and IAF when a rapidly growing spindle cell tumor is encountered in a post-GIST patient.