Epithelioid inflammatory myofibroblastic sarcoma: a case report.

Inflammatory myofibroblastic tumor (IMT) of the lung is a rare malignancy with few cases reported in the literature. Histologically, it is composed by spindle cells and an infiltrate of inflammatory cells. Children and young, non-smoking adults constitute the majority of cases, the clinical behavior ranges from a benign entity to a malignant process with rapid recurrence and metastatic progression. We present a case of epithelioid inflammatory myofibroblastic sarcoma (EIMS) of the pleura, a malignant variant of IMT, which was initially treated with debulking surgical resection followed by systemic chemotherapy. The tumor was found to have an anaplastic lymphoma kinase (ALK) gene rearrangement. An ALK directed tyrosine kinase inhibitor was used with an impressive response, the patient remains in remission nearly 1 year after presentation. The pathogenesis, pathologic findings, clinical behavior and imaging of pulmonary EIMS are discussed.