Serum electrolytes

    Kevin Hohner, age 37, has shortness of breath and cough. He reports weight loss of 10 pounds in the last 2 months. He state that he has had pneumonia twice in the past year. He has a prior history of unprotected homosexual sex with multiple partners but has been in a stable relationship for the past six years. HIs partner is HIV negative, but Mr. Hohner has not been tested for HIV. His physical exam is as follows: • Vital signs normal except for elevated respiratory rate • Crackles in lower half of lung fields, with inspiratory and expiratory rhonchi • Reddish-brown, flat lesions on chest and arms. • Cardiac, abdominal and neurologic examinations normal • Perianal vesicular and ulcerative lesions Labs: • Serum electrolytes, BUN, and creatinine are normal • Chest x-ray shows diffuse infiltrates • CD4+ cells 180 cells/microliter (low); CD4+/CDB+ cells ratio below normal • Anti-HIV antibodies present: HIV viral particle load substantial Mr. Hohner's diagnoses are AIDS, pneumocystis pneumonia, Kaposi sarcoma and perianal herpes simplex virus. 1. Why did Mr. Hohner develop Kaposi sarcoma, an unusual type of cancer?