TCL-084 Subcutaneous Panniculitis-Like T-Cell Lymphoma With Co-Existing Lupus Panniculitis: A Case Report.

INTRODUCTION: Subcutaneous panniculitis-like T-cell lymphoma (SPTL) is an extraordinary form of peripheral T-cell lymphoma, accounting for much less than 1% of all non-Hodgkin lymphoma. It usually happens amongst women with a median age of onset of 36 years. It can arise with autoimmune disease ~20%. SPTL may also coexist with different autoimmune diseases (e.g., lupus erythematosus [LE]) despite normal workup.

CASE: A 44-year-old woman presented with a small, 2×2 cm mass on her right inner thigh that was erythematous, non-movable, and tender. She has had repeated admissions due to soft tissue infection and persistent pleural effusions. She experienced eruption of numerous, nonpruritic, erythematous maculopapular rashes on her body. Initial laboratory workup showed persistent cytopenia (anemia and leukopenia), >10x elevated ferritin and LDH, and elevated transaminases and procalcitonin. Other work-ups, such as bone marrow studies, pleural fluid flow cytometry (comprehensive lymphoma panel), CT-PET, and connective tissue disease (LE and antiphospholipid syndrome) panels, were unremarkable. SPTL with LE profundus overlap was diagnosed upon review of the nodule biopsy report. The patient was treated with prednisone and cyclosporine with a good response, as seen on follow-up.

DISCUSSION AND SUMMARY: SPTL can arise in patients with LE or vice versa. The illness itself may also present initially as benign panniculitis, eczema, dermatitis, psoriasis, cellulitis, or other skin and soft tissue infections. The culprit behind this disease is a HAVCR2 (Hepatitis A Virus Cellular Receptor 2) mutation, which occurs in 60% of SPTL cases and is more typically seen in Asian and Eastern patients. Its presence is related to HLH-refractory and severe disease course. For patients with indolent course, the suggested first-line remedies encompass immunosuppressive agents together with prednisone, cyclophosphamide, or methotrexate; extreme conditions with aggressive infiltrative lymphocytes may also require a combination of chemotherapy regimens. In patients resistant to chemotherapy, cyclosporine A alone or combined with steroids causes desirable effects, including in HPS patients.

CONCLUSIONS: SPTL is a diagnostic challenge. A high index of suspicion and correlation of clinical, imaging, and histopathologic reports will increase the probability of detecting this disorder, consequently lessening the probability of the delay in treatment. Indolent courses have desirable overall survival, except for patients presenting with HLH/HPS upon diagnosis.