A. Langford

Oral hyperpigmentation in HIV-infected patients

Six cases of oral hyperpigmentation in HIV-infected patients are reported. While in two patients the lesions could be related to systemic clofazimine or ketoconazole therapy, in the other patients the cause remained unknown. Clinically, the pigmentations were characterized by a sudden onset and the appearance of well-defined, brown-black macules in the buccal mucosa, the gingiva, the hard palate, or the lateral borders of the tongue. In one patient, longitudinal hyperpigmented striae were observed on all fingernails and toenails. Histologically, hyperpigmentations associated with systemic medication revealed accumulation of melanin in phagocytes and extracellularly within the connective tissue. In those lesions with unknown cause, melanin was restricted to keratinocytes of the basal cell layer or to extracellular foci in the lamina propria. The clinical and histologic findings, as well as differential diagnosis, are discussed.

Immunohistochemical detection of HIV structural proteins and distribution of T-lymphocytes and Langerhans cells in the oral mucosa of HIV infected patients

Seventeen biopsies taken from oral mucosa of HIV infected patients were analysed for the distribution of CD4+/CD8+ T-lymphocytes and Langerhans cells. The results were evaluated statistically. An increase in the absolute number of CD4+ and CD8+ cells in HIV infected patients without clinical symptoms, ARC or AIDS was seen in the connective tissue stroma when compared with normal oral mucosa from sero-negative patients. However, the ratio between CD4+/CD8+ cells was decreased due to the disproportionate increase of CD8+ cells. These findings did not show statistical correlation with the clinical status of the infection. In contrast to the increase in absolute number of CD4+/CD8+ cells the number of Langerhans cells was unchanged when compared with the control group. Using four different monoclonal antibodies against virus structural proteins (2xanti p24, gp41, gp120) two of 26 patients showed labelled cells in consecutive sections in the same connective tissue areas. It was assumed that latently infected mononuclear cells invaded the oral mucosa together with uninfected cells of the cellular immune system.

Oral manifestations of AIDS-associated non-Hodgkin's lymphomas

While B-cell lymphomas are frequently found in AIDS patients, reports on oral manifestations are rare. Among a group of 465 HIV-infected patients 5 presented with primary oral manifestations of a malignant B-cell lymphoma. The primary site of manifestation was the maxilla in 3 cases and the mandible in 2 cases. Based on the histological and immunohistochemical examination the tumors were differentiated as Burkitts lymphoma (n = 1), as anaplastic large cell (ALC) lymphoma of the B-cell type (n = 1), as high-grade non-Hodgkins lymphoma not classifiable according to the Kiel classification (n = 1), as immunoblastic-plasmoblastic lymphoma (n = 1), and as centroblastic lymphoma (n = 1). Serum samples were negative for HTLV-I antibodies in 5/5 cases.

Regression of oral Kaposi's sarcoma in a case of AIDS on zidovudine (AZT).

A case with oral Kaposis sarcom (KS) is reported that regressed during therapy with Zidovudine (AZT) which was started 5 months after the first dermal and oral tumours were noted. After 6 months of treatment the absolute number of T‐helper cells had increased from 54/μl to 232/μl and the ratio of T‐helper to T‐suppressor cells from 0.15 to 0.3. During the same time the lesions of KS on the gingiva, uvula and the body as well as the face disappeared. The lesion of KS on the hard palate regressed.

Ultrastructural and immunohistochemical findings in oral hairy leukoplakia

Three cases of HL from the lateral border of the tongue of male homosexual AIDS patients were investigated by thin section electron microscopy. Keratinocytes contained condensed chromatin in their pyknotic nuclei and a few organelles in the oedematous cytoplasm. Chromatin was in close association to the nuclear membrane and showed a punched-out appearance. Particles typical of the herpes virus group were abundant in the upper two thirds of the epithelium in all three cases. Virus particles were seen frequently in the nuclei of the ballooned keratinocytes, but rarely in cells containing Candida albicans. Viral nucleocapsids were observed budding at the inner nuclear membrane, thereby acquiring the prospective viral envelope. Complete, enveloped virions were found in the endoplasmic reticulum and in the extracellular space. These virions were identified immunohistochemically as Epstein-Barr virus (EBV) using two monoclonal antibodies directed against EBV capsid and membrane antigen, respectively. Candida albicans was observed in the stratum corneum and in the upper layer of the stratum spinosum. Special cytoplasmic tubular structures arranged in parallel bundles were found in koilocytotic cells in addition to characteristic membrane structures composed of undulating convoluted membranes. Epithelial basement membranes were always intact.

Primary intraosseous AIDS-associated Kaposi's sarcoma. Report of two cases with initial jaw involvement

AIDS-associated Kaposis sarcoma (KS), which in 80% of cases occurs in the oral cavity, usually presents with characteristic clinical features such as brown-bluish pigmented macules or tumorous lesions. In later stages the tumor, most probably originating from the vascular endothelium, may secondarily induce erosion of the underlying bone. The primary, intraosseous occurrence of KS has prompted the present 2 case reports. The tumor presented as extensive, diffuse osteolysis within the mandible without causing clinical symptoms. Although rare, intraosseous KS must be included in the differential diagnosis of isolated bone defects in HIV-infected patients.

Osteosarcoma of the maxilla. Case report and ultrastructural study.

An osteosarcoma, occurring in the maxillary alveolar ridge of a 17-year-old girl is presented. The tumor consisted predominantly of pleomorphic, mainly osteoblast-like and anaplastic cells. At the ultrastructural level the osteoblast-like cells were characterised by excentrically situated lobed nuclei, extensively swollen, dilated and rough endoplasmic reticulum (RER), polymorphism of mitochondria and sparse Golgi-systems. The undifferentiated cells were characterized by large, electron-lucent nuclei and paucity of non-dilated RER and mitochondria. The intercellular matrix contained collagen fibers with areas of focal collections of calcification.