Primary Skeletal Muscle Lymphoma Presenting as Acute Compartment Syndrome of the Forearm: A Case Report

Primary skeletal muscle lymphoma rarely causes compartment syndrome. We encountered a case of diffuse large B-cell lymphoma that presented as acute compartment syndrome. A 70-year-old woman developed subacute swelling and pain in the left forearm without an identifiable cause. Compartment pressures were markedly elevated at 110 mmHg in the dorsal and 125 mmHg in the deep volar compartments. Despite emergent fasciotomy, her symptoms continued to progress. Intraoperative muscle biopsy revealed diffuse large B-cell lymphoma with overexpression of <i>MYC</i> and <i>BCL2.</i> After the initiation of R-CHOP (Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone) chemotherapy, the forearm swelling and pain subsided, and the fasciotomy wound was managed conservatively until closure. Because of the high-risk double-expressor profile, the regimen was escalated to EPOCH-R (Etoposide, Prednisone, Oncovin (Vincristine), Cyclophosphamide, hydroxydaunorubicin (Doxorubicin), and Rituximab), and six courses achieved complete remission. The patient experienced no recurrence during four years of follow-up and developed no sequelae related to compartment syndrome. This case highlights the importance of rapid diagnosis through tissue sampling at the time of fasciotomy. Prompt initiation of chemotherapy is directly linked to both survival and preservation of limb function.