2019 Volume 56 Issue 2 Pages 212-215
A 1-year-and-9-month-old boy was referred to us for swelling of the left forearm. Magnetic resonance imaging revealed a solid tumor in the forearm about 6 cm in size. There was no metastatic lesion, and he underwent biopsy. Clinically, he was suspected of having infantile fibrosarcoma on the basis of the results of histopathological analysis and his clinical course. However, a central pathological review disclosed a suspicious myofibroma. Chemotherapy consisting of vincristine, actinomycin, and ifosfamide was carried out but the tumor size remained unchanged. Chemotherapy was discontinued 2 months after initiation. However, the tumor size increased 3 months after the discontinuation of chemotherapy; hence, he underwent marginal resection 4 months after the discontinuation of chemotherapy. The pathological diagnosis was unclassified spindle cell sarcoma. Local irradiation and 3 cycles of chemotherapy with vincristine, ifosfamide, and doxorubicin were carried out, and the treatment was completed. We recommend collecting another biopsy sample for histopathological examination if the pathological diagnosis is incompatible with the clinical course.