A case of inflammatory myofibroblastic tumor harboring EML4-ALK fusion with a brain metastasis responding to alectinib.

Metastatic inflammatory myofibroblastic tumor (IMT) is very rare and detailed reports on diagnosis and treatment are limited. Here, we report a case of metastatic IMT with ALK rearrangement. A 73-year-old woman was diagnosed with IMT involving a brain metastasis. Next generation sequencing (NGS) panel testing with Oncomine dx target test revealed that her tumor was positive for EML4-ALK. Treatment with alectinib was initiated, resulting in remarkable shrinkage of both the primary tumor and the brain metastasis. This report is the first to identify ALK rearrangement in IMT using a commercially available NGS panel testing, followed by treatment with alectinib. This case suggests that NGS panel testing may be useful in the diagnosis and treatment of patients with metastatic IMT.