Gastrointestinal (GI) stromal tumors are mesenchymal tumors that arise from the GI tract. In rare cases, these tumors are found in intra-abdominal sites unrelated to the GI tract and are immunohistochemically similar to their GI tract counterparts. Primary pancreatic GI stromal tumors are very rare, with only 4 previous cases reported.
Showalter SL, Lloyd JM, Glassman DT, Berger AC. Extra–Gastrointestinal Stromal Tumor of the PancreasCase Report and a Review of the Literature. Arch Surg. 2008;143(3):305-308. doi:10.1001/archsurg.2007.68