A Case of Extranodal Metastasis of Primary Bone Lymphoma in the Lower Extremity.

Primary bone lymphoma is a rare disease, accounting for less than 5% of all extranodal lymphoma. Although the femur is cited as being the most common site, primary bone lymphoma is rare, accounting for less than 1% of all non-Hodgkin's lymphoma. Herein we present a case of diffuse B-cell-type malignant lymphoma manifested as a large soft-tissue mass of the leg, via metastasis of primary non-Hodgkin's lymphoma of the femur, which went untreated. We highlight the advantages of various imaging modalities used throughout the process of diagnosis and treatment because accurate and early diagnosis are essential. This case gives us a unique opportunity to witness the rapid progression of metastasis and an atypical location.