ABSTRACT
Electron microscopic investigation of biopsy materials from Kaposi sarcoma (KS) skin lesions of 2 African AIDS patients occasionally revealed fungal cells within the tumor tissue. The spherical cells were surrounded by a triple-layered cell wall and were not encapsulated. The ultrastructural characteristics of the cells resemble those of Candida albicans organisms. Neither patient showed clinical signs of a generalized fungal infection. The presence of Candida albicans in the KS tissue specimens seems to represent an early and asymptomatic stage of cutaneous candidiasis in the 2 severely immunocompromised AIDS patients.
Subject(s)
AIDS-Related Opportunistic Infections/microbiology , Candida albicans/isolation & purification , Microscopy, Electron, Transmission/methods , Sarcoma, Kaposi/microbiology , Skin Neoplasms/microbiology , AIDS-Related Opportunistic Infections/immunology , AIDS-Related Opportunistic Infections/pathology , Adult , Candida albicans/ultrastructure , Humans , Immunocompromised Host , Male , Sarcoma, Kaposi/immunology , Sarcoma, Kaposi/pathology , Skin Neoplasms/immunology , Skin Neoplasms/pathologyABSTRACT
Biopsied tissue specimens from 40 cases of classic, atypical classic, endemic, and AIDS-associated Kaposi's sarcoma (KS) were investigated by electron microscopy. To search for ultrastructural differences between non-AIDS-associated KS and AIDS-associated KS, the occurrence of the following 2 ultrastructural abnormalities of the rough-surfaced endoplasmic reticulum in KS cells was evaluated semi-quantitatively: tubuloreticular structures (TRS) and intracisternal paracrystalline inclusions (IPI). These peculiar structures were found in 23 of the 40 KS cases. Two types of TRS could be distinguished: loose TRS (LTRS) and compact ones (CTRS). LTRS were observed in endothelial cells of tissue from all the different epidemiological types of KS. CTRS were confined to AIDS-associated KS. IPI were present in endothelial tumor cells of only 3 non-AIDS-associated KS cases. The study shows that in cells of KS tissue only CTRS, but not LTRS, are an ultrastructural marker for AIDS-associated KS.
Subject(s)
Endoplasmic Reticulum, Rough/ultrastructure , Endothelium, Vascular/ultrastructure , Inclusion Bodies/ultrastructure , Sarcoma, Kaposi/blood supply , Sarcoma, Kaposi/pathology , Acquired Immunodeficiency Syndrome/complications , Acquired Immunodeficiency Syndrome/pathology , Adult , Aged , Female , Humans , Male , Microscopy, Electron, Transmission , Middle Aged , Sarcoma, Kaposi/etiologyABSTRACT
Tissue from an extirpated cervical lymph node of an African AIDS patient with tuberculosis was investigated with the electron microscope. A peculiar cytoplasmic structure was found in histiocytic cells of the lymph node tissue. This structure consisted of a loose aggregation of convoluted, folded curvilinear membranes, demonstrating C-shaped, U-shaped, and S-shaped profiles according to the plane of section. These curvilinear membranous formations (CMF) were formed by 2 parallel-running unit membranes separated by a narrow electron-lucent space. Continuities of CMF with rough-surfaced endoplasmic reticulum were sometimes observed. Occasionally, an electron-dense, blurred cytoplasmic area was seen between 2 neighboring CMF. Several CMF also formed a seastar-like configuration by mergence in such an area. It is unknown whether the HIV infection of the patient was the primary cause of the CMF.
