Imatinib

Abstract

Histiocytic sarcoma: case report A 68-year-old woman developed histiocytic sarcoma (HS) during treatment with imatinib for gastrointestinal stromal tumor (GIST). The woman, with suspected recurrent GIST of stomach, was admitted to the hospital for an exploratory laparotomy with gastric wedge resection of greater curvature. Six year prior to presentation, she developed GIST which treated with imatinib [Gleevec; routes and dosages not stated] and partial gastrectomy. Four months before the presentation, she developed abdominal stress and chronic constipation. Subsequent laboratory test showed mild anaemia. A CT scan of abdomen revealed gastric mass in the left upper quadrant. Based on the biopsy of the gastric mass and immunohistochemistry, recurrent GIST was diagnosed. Subsequently, she had received imatinib for 6 months. Following 6 months of imatinib therapy, a CT scan was performed which showed slight decreased of tumour size. Thereafter, she was admitted for selective partial gastrectomy (current presentation). The histopathological examination of partial gastrectomy showed features of histiocytic sarcoma (HS). At the same time, no residual GIST was observed in the entire gastrectomy specimen. It was concluded that, she had developed HS secondary to imatinib due to transdifferentiation of GIST to HS caused by interaction of interstitial cells of Cajal with the effects imatinib and other intrinsic host factors [duration of treatment to reaction onset and outcome not stated].