Abstract:

Epithelioid inflammatory myofibroblastic sarcoma (EIMS) is a specific subtype of inflammatory myofibroblastic tumor. It is a rare malignant mesenchymal tumor with clinical features such as anaplastic lymphoma kinase (ALK) positivity, high aggressiveness, and poor prognosis. ALK inhibitors (TKI) are targeted drugs for the treatment of these tumors. We report a case of pelvic-abdominal EIMS that was difficult to be resected by surgery. The patient was a young woman with clinical manifestations of left lower abdominal pain with fever, and was clearly diagnosed by pathology as EIMS with RANBP2-ALK fusion mutation of ALK gene, and the symptoms of abdominal pain and other symptoms were rapidly relieved after TKI-targeted therapy, and with the prolongation of the time of administration, the lesion in the pelvic-abdominal cavity progressively shrunken. The patient was treated with TKI for 3 years, and no signs of recurrence or metastasis of the tumor lesions were seen on any of the imaging examinations. A successful case of sustained response to targeted therapy is provide, and confirm the possibility of TKI targeted therapy for patients with unresectable, refractory ALK-positive EIMS.

Key words: Epithelioid cells, Sarcoma, Anaplastic lymphoma kinase, Mutation, Gene fusion, Crizotinib