Epithelioid inflammatory myofibroblastic uterine sarcoma

Epithelioid inflammatory myofibroblastic sarcoma is an extremely rare and aggressive variant of inflammatory myofibroblastic tumor, characterized by high mitotic activity, epithelioid cell morphology, and the expression of muscle markers and ALK protein resulting from ALK gene fusions. For many years, inflammatory myofibroblastic tumors of the uterus remained poorly studied and were often misdiagnosed as leiomyoma, leiomyosarcoma, or endometrial stromal sarcoma. In the latest WHO Classification of Tumors of the Female Reproductive System (2020), this entity has been assigned to a separate category based on its distinct morphological and molecular-genetic features. Epithelioid inflammatory myofibroblastic sarcoma represents an exceptionally rare variant of inflammatory myofibroblastic tumor in the female genital tract. ALK gene rearrangements are characteristic for inflammatory myofibroblastic tumors and provide opportunities for targeted therapy with ALK inhibitors. This article presents a rare clinical case of uterine inflammatory myofibroblastic sarcoma. The case highlights the importance of accurate morphological and molecular verification of the diagnosis and demonstrates the effectiveness of second-generation ALK inhibitors in managing aggressive forms of inflammatory myofibroblastic tumors of uterine localization.