Multifocal Primary Cutaneous Diffuse Large B-Cell Lymphoma, Leg Type, Presenting on Face and Chest: Complete Remission With R-CHOP

ABSTRACT: Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT), is an aggressive subtype of primary cutaneous B-cell lymphoma that predominantly affects the lower extremities of elderly individuals. We report a rare case of a 79-year-old woman presenting with rapidly enlarging, erythematous-to-violaceous tumors and plaques on the face, chest, left upper arm, and upper back, an uncommon non-leg manifestation of PCDLBCL-LT, confirmed by histopathology and immunohistochemistry. The patient was successfully treated with six cycles of the rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) therapy, achieving complete remission with no relapse during 1.5 years of follow-up. This case emphasizes that PCDLBCL-LT can present in locations outside the legs, highlighting the need for early recognition and systemic therapy in atypical locations.