Imaging of lymphoma of the musculoskeletal system

A Rare Case of Aggressive Non-Hodgkin's Lymphoma of the Muscle in a Young Male Presenting as Necrotizing Myofasciitis

Non-Hodgkin's lymphoma (NHL) involving skeletal muscle is generally found to be a secondary metastasis and extremely rarely as a primary site of malignancy. Furthermore, in HIV patients, an increased incidence of lymphomas may be identified within the first six months of highly active antiretroviral therapy (HAART) initiation unmasked by immune reconstitution inflammatory syndrome (IRIS). We illustrate an extremely rare instance of NHL of the skeletal muscle in a young immunocompromised male with HIV/AIDS presenting as necrotizing myofasciitis complicated by compartment syndrome and hemodialysis-refractory type B lactic acidosis. A young Hispanic male with AIDS was admitted for acute left thigh pain and was soon found to have abscess formation with compartment syndrome requiring thigh fasciotomy. During the course of the ICU stay, the patient's clinical status acutely worsened with sepsis-induced multiorgan failure, including acute renal and acute liver failure requiring N-acetylcysteine and severe refractory metabolic acidosis requiring renal replacement therapy. Repeat imaging demonstrated diffuse myonecrosis. Left thigh muscle biopsy confirmed aggressive NHL of skeletal muscle. Despite months of arduous medical management in ICU, doxorubicin, vincristine, cyclophosphamide chemotherapy with concurrent high-dose prednisone for the vented patient, and intermittent curves of improvement, our patient succumbed to the nature of the disease and subsequently died from severe sepsis from the immunocompromised state. Interestingly, our patient's initial CD4 count was 1, which improved to 96 after five months of HAART, raising concerns for IRIS lymphoma. Given such rapid improvement with chemotherapy, the possibility of IRIS-related lymphoma, and the surprising dearth of data for chemotherapy use in critically ill patients on mechanical ventilation, more research is needed in these topics to better approach such complicated patients.

Lymphoma Presenting as a Soft Tissue Mass

Teaching Point: Lymphomatous involvement of the skeletal muscle is rare; however, because lymphoma can be treated with chemotherapy, it is crucial to consider it in the differential diagnosis of a soft tissue mass in the appropriate clinical and imaging setting.

Primary skeletal muscle diffuse large B cell lymphoma: A case report and review of the literature

The occurrence of primary extranodal non-Hodgkin's lymphoma (NHL) of soft tissue is rare, particularly in skeletal muscle. The present study describes a case of diffuse large B cell lymphoma of the right lower extremity and provides a detailed review of the literature associated with this disorder, with the aim of improving the future diagnosis and therapy of extranodal NHL. The present case report was of a 76-year-old woman who presented with a right thigh and calf mass. In view of the tumor's location and the patient's age, soft tissue tumors were considered to be soft tissue sarcoma. Imaging scans were performed to determine the location and size of the tumor, followed by a biopsy of the muscle. Histopathological examination then yielded a diagnosis of diffuse large B cell lymphoma. The patient then underwent 4 cycles of chemotherapy. There was evident relief of pain and swelling in the right extremity; however, positron emission tomography/computed tomography (PET/CT) determined insufficient treatment efficacy. Chemotherapy was adjusted for 2 cycles; however, the patient suffered an aggravation of edema, so a different chemotherapy regimen of bleomycin, cytarabine, vincristine, cyclosphamide and dexamethasone (BCOAD) was performed for a further 2 cycles. The edema was alleviated and magnetic resonance imaging revealed shrinkage of the lower limb mass and the right thigh mass was undetectable. In conclusion, the present case report demonstrated that PET/CT may help determine the efficacy of chemotherapy treatment and that the BCOAD chemotherapy regimen may be more effective than standard treatments in certain cases.

Non-Hodgkin's Lymphoma of the Knee: A Case Report

Primary musculoskeletal lymphoma presenting as monoarthritis is very rare. Less than 20 cases have been reported. The ultrasound appearances have not been reported to date. We present a young female of primary knee lymphoma with synovial involvement presenting as monoarthritis. The ultrasound and MRI features are discussed.