A rare case of primary cutaneous diffuse large B-cell lymphoma, leg type, presenting as cellulitis: a case report.

Primary cutaneous diffuse large B-cell lymphoma, leg type, accounts for only 4% of all cutaneous lymphomas and bears a worse prognosis than other cutaneous B-cell lymphomas. Diagnosis at an early stage may be difficult due to its nonspecific manifestations. We report an 88-year-old female who was brought to our emergency department due to two rapidly growing painful skin lesions with local redness and swelling on her right lower leg. We performed incisional biopsy of the two right lower leg skin lesions and sent the specimens for histopathological examination. The pathological examination was compatible with diffuse large B-cell lymphoma. Primary cutaneous diffuse large B-cell lymphoma, leg type, is a rare condition that can present as skin cellulitis, thereby misleading clinicians and resulting in delayed treatment. This diagnosis should be considered when assessing skin lesions.