Desmoid Fibromatosis in the Multifidus Muscle Misdiagnosed as Intramuscular Schwannoma by Incisional Biopsy: A Case Report.

Desmoid fibromatosis is a locally aggressive myofibroblastic neoplasm. In this study, we report a case of desmoid fibromatosis in the paraspinal muscle that was misdiagnosed as intramuscular schwannoma through incisional biopsy at another hospital. We performed total excision of the mass lesion with a clear margin. We found that for an accurate diagnosis, magnetic resonance imaging, incisional biopsy and excisional biopsy were required.