Abstract
Malignant peripheral nerve sheath tumor (MPNST) is a rare sarcoma with aggressive clinical zehavior. Epithelioid MPNSTs (EMPNSTs) are distinct and rare variant of MPNST. They are described by the World Health Organization and they account for <5% of these tumors and have unclear clinical behavior. Due to the rarity of the EMPNST and the overlapping features and similarity with other tumors exhibiting epithelioid cytomorphology, EMPNSTs impose a diagnostic challenge. Therefore, it is critical to be aware of this entity and other mimickers to reach the correct diagnosis. Hence, this is a case of a 45-year-old lady who presented with persistent left ankle swelling for 2 years. A biopsy was performed, which confirmed the diagnosis of EMPNST. The aim of reporting this case of this rare tumor with this presentation was to help both pathologists and orthopedic oncology surgeons to understand the behavior of this tumor and help differentiate it from mimickers, and enrich interested readers’ knowledge with the presented literature review.