Primary Skeletal Muscle Lymphoma: A Case Report and Literature Review

Abstract

Background
Lymphomatous involvement of the muscle is a rarely seen disorder, constituting 0.1-1.4% of all extranodal lymphomas. It may
be seen as the intramuscular involvement of disseminated disease, as an extension from adjacent bone or lymph nodes, or as
primary extranodal lymphoma. Primary lymphoma of the skeletal muscle mainly consists of B-cell non-Hodgkin lymphoma
(NHL) (>95%).
Case Presentation
A 50-year-old male patient presented with progressive swelling and pain in his right flank area over a period of one year. Ultrasound
(US) was done, and it showed diffuse enlargement of pelvic and limb muscles with hypoechoic regions that irregularly
infiltrated normal muscle tissue. An incisional biopsy was done, and the histopathologic diagnosis was diffuse large B-cell lymphoma
(DLBCL).
Conclusion
Primary intramuscular lymphoma is extremely rare. Nevertheless, it should be considered a differential diagnosis in patients
presenting with intramuscular tumors.