We report a case of a 58-year-old man who presented with a rapidly growing proliferative lesion on the left lower limb, clinically resembling a soft tissue sarcoma 3 years after renal allograft. There was no evidence of systemic involvement on bone marrow needle aspiration and computed tomography (CT) scans of the chest and abdomen. The lesion turned out to be primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL LT), as defined in the recent World Health Organization-European Organization for Research and Treatment of Cancer (WHO-EORTC) classification of cutaneous lymphomas by skin biopsy. Immunosuppression reduction, chemotherapy with CHOP regimen and local radiotherapy induced complete remission of the tumor.