[Gastrointestinal stromal tumor of the abdominal wall. An unusual localization of a rare tumor]

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract. We describe here for the first time a patient with a huge GIST of the abdominal wall without any relation to the gastrointestinal tract, omentum, or mesentery. With regard to the size of 24 cm and a low mitotic index, this GIST is considered an intermediate risk for metastasis. Radical surgical resection was performed with negative pathologic resection margins. The classic immunohistochemical phenotype of the tumor described facilitates the differential diagnosis to exclude abdominal desmoid tumor and solitary fibrous tumor (SFT). In the case of metastasis, therapeutic nihilism no longer seems justified with the availability of imatinib, a tyrosine kinase inhibitor, which shows encouraging results in the therapy of metastatic GIST.