Between December 1986 and December 1988, the Italian Cooperative Group on AIDS-Related Tumours documented 49 HIV-related tumours other than malignant lymphomas (ML) and Kaposi's sarcomas (KS), predominantly among HIV-infected intravenous drug abusers (IVDA). Of 12 germinal testicular tumours collected, six were seminomas, two of which were pure embryonal and the other four embryonal mixed. Cervical carcinoma was observed in nine IVDAs (intraepithelial in eight and advanced, with rapid progression, in one). Lung cancer associated with HIV infection was reported in eight patients, of whom four had an adenocarcinoma, two a small cell carcinoma, one an epidermoid carcinoma and one a mesothelioma. All patients with non-small-cell-lung cancer (SCLC) were at stage III, while those with SCLC and mesothelioma had limited disease. Five out of eight presented with limited disease at onset. The median age was low; lung cancer occurred predominantly in young adults, of whom all but one were smokers. Three patients could not be treated; four died while on treatment because of progression of the neoplasia and one died of an overdose. Acute lymphoblastic leukaemia (ALL) was diagnosed in five patients. The immunophenotype was always Burkitt-like (L3), and acute myeloblastic leukaemia (M2) was diagnosed in one. Of the central nervous system (CNS) tumours, two cases of glioblastoma and one of medulloblastoma were described. Two cases of young adults with multiple myeloma and two cases of colorectal carcinoma were also reported. One case of chronic lymphocytic leukaemia, one anorectal carcinoma, one oral carcinoma, one pancreatic carcinoma, one thymoma, one kidney carcinoma, one malignant melanoma and thyroid carcinoma were also found.(ABSTRACT TRUNCATED AT 250 WORDS)