Myofibroma with Atypical Features can Mimic Low-Grade Myofibroblastic Sarcoma: Two Paediatric Cases.

Myofibroma is a rare benign mesenchymal tumor that frequently affects the pediatric population with a predilection for the head and neck region. About 10% of myofibroma cases, presenting atypical features, can be misinterpreted as low-grade myofibroblastic sarcoma (LGMS), with therapeutic and prognostic impact. Here, we report two pediatric cases of benign myofibroblastic tumors, one of them showing typical characteristics of myofibroma, the other was an atypical myofibroma, which initially mimicked low-grade myofibroblastic sarcoma. Atypical myofibromas, despite its distinctive characteristics, follow a benign course, similar with typical myofibroma. It is necessary to distinguish atypical myofibroma from low-grade myofibroblastic sarcoma and avoid unnecessary invasive therapy.