A 66-year old male patient was known being HIV-positive for more than 10 years at CDC stage C3. At regularly presentation, a transient viremia with HIV PCR of 322 cps/ml and CD4=120/μl was detected under therapy with Tenofovirdisaproxil fumarate, Emtricitabine and Norvir-boosted Atazanavir. However, the general condition of the patient was stable for years. Additionally, he demonstrated a skin lesion on his left lower leg, which occurred few weeks prior to consultation without any further symptoms. Dermatological clinical examination showed a single 10 x 7 centimeters large erythematous-brownish infiltrated plaque on the left lower leg (Fig. 1). Under the clinical diagnosis of cutaneous lymphoma a punch biopsy was taken from the affected area.