Granulocytic Sarcoma of the Sciatic Nerve Manifested as Relapse of Acute Myeloid Leukemia: A Case Report

ABSTRACT

Granulocytic sarcoma is a form of extramedullary involvement of primitive myeloid cells. A 69-year-old male patient, with history of acute myeloid leukemia (AML) in remission state for 4 years, presented numbness, radiating pain and progressive motor weakness in left leg. MRI showed perineural thickening of the left sciatic nerve with increased signal intensity on fat-saturated T2-weighted image. The patient underwent surgical excision and the pathology was confirmed as granulocytic sarcoma. Its involvement of the peripheral nerve is extremely rare and also unusual to be the only evidence of AML relapse. In this case, we figured out the MRI feature of granulocytic sarcoma involving sciatic nerve, emerged as a sole manifestation of AML relapse.