In the early 1980s, acquired immunodeficiency syndrome was recognized and described in men who had sex with previously healthy men and young people, who were affected by atypical pneumopathy caused by an opportunistic microorganism, identified as Pneumocystis carinii, and now known as Pneumocystis jiroveci, evidenced by purplish or brown nodular lesions revealed in the histopathological Kaposi's sarcoma. Kaposi's sarcoma is the most frequent neoplasm in patients with human immunodeficiency virus infection. Its pathophysiology has been associated with the presence of a herpes virus, whose etiologic agent is a member of the herpesvirus or herpes virus type 8 family(HHV-8), which can be transmitted through sexual contact, which would be implicated in the onset of the disease. This case report seeks to present the diagnosis and bring the light of knowledge to the Dentist the need to launch hands of complementary examinations and to effectively seek important therapeutic measures in the treatment of the pathology. In this case, with the start of HAART administration, the tumor regressed, leading the patient to well being, and with evident improvements in their quality of life.