Bone Biopsy Confirmed Imatinib-Induced Bone Marrow Necrosis in Patient with Gastrointestinal Tumor: A Case Report

Imatinib mesylate is an effective, small-molecule, selective tyrosine kinase inhibitor, which inhibits BCR-ABL in patients with chronic myeloid leukemia, c-kit in patients with gastrointestinal tumor (GIST), and platelet-derived growth factors in hypereosinophilic syndrome. Above all, bone marrow necrosis is a rare complication of imatinib usage. If newly developed increased opacity bone lesions are seen in patients with metastatic GIST, it is usual to consider those lesions as bone metastasis. Also, it is true that making a differential diagnosis between bone marrow change (bone marrow necrosis) and disease progression (bone metastasis) is both clinically and radiologically difficult. Because it may alter treatment options according to early distinguish bone metastasis and imatinib related-bone necrosis, a bone biopsy is recommended. Here, we report a case that a biopsy confirmed bone marrow necrosis due to imatinib, even though investigations such as magnetic resonance imaging, and whole-body bone scan indicated more favor to the metastatic lesion.