Biomedical subjects
Carl Allen
Publications and source records attributed to Carl Allen.
Oral plasmablastic lymphomas in AIDS patients are associated with human herpesvirus 8.
Human herpes virus type 8 (HHV8) has been strongly associated with Kaposi sarcoma, primary effusion lymphoma (PEL), and Castleman's disease. To our knowledge, infection by this virus has not been strongly associated with other hematopathologic malignancies. We examined five oral cavity lymphomas from men with AIDS for HHV8 and HIV-1 by reverse transcriptase in situ polymerase chain reaction, as well as for Epstein-Barr virus (EBV) (EBER-1, -2) using in situ hybridization and HHV8 protein with immunohistochemistry. Four of these tumors were plasmablastic lymphomas; the final case was diffuse large B-cell lymphoma. Most of the neoplastic cells in these five lymphomas contained HHV8 RNA and protein. Further, the four plasmablastic lymphoma cases had tumor cells that contained EBV. HIV-1 RNA was not detected in the tumor cells but was noted in surrounding benign T cells. In comparison, HHV8 RNA was not detected in any of the five oral cavity lymphomas from people who did not have acquired immunosuppression nor in five lymphomas from AIDS patients that were located at a site other than the oral cavity. It is concluded that oral cavity lymphomas from people with AIDS are strongly associated with infection by HHV8 and EBV. Given the poor prognosis of oral cavity lymphomas in immunocompromised patients, therapy directed against the HHV8 and EBV infection may be of therapeutic value.
Juvenile xanthogranuloma of the oral cavity in children: a clinicopathologic study.
PURPOSE: This clinicopathologic study describes the histopathologic, immunocytochemical, and electron microscopic features of oral juvenile xanthogranuloma (JXG) in children. DESIGN: The study population consisted of 5 children (5 months to 10 years of age) with biopsy-proven JXGs obtained for consultation. RESULTS: Lesion sites were gingiva, buccal mucosa, and tongue and were described by the clinicians as (1). irritation fibroma; (2). granulation tissue; (3). pedunculated granular nodule; (4). papilloma-like lesion; and (5). brown-red umbilicated papule. Tissue was available for histopathologic (n = 5), immunocytochemical (n = 5), and ultrastructural (n = 3) studies. Three cases showed early JXG lesions possessing abundant histiocytes, but lacking Touton giant cells. The other 2 cases had classic JXG lesions with vacuolated histiocytes and Touton giant cells. Immunocytochemical findings were (1). CD68 (KP1, PGM1), moderate to diffuse; (2). fascin, moderate to diffuse; (3). factor XIIIa, focal to diffuse; (4). alpha-1-antitrypsin, moderate to diffuse; (5). S-100 protein, focal to diffuse; and (6). CD1a, negative in all cases. Ultrastructural examination displayed histiocytic and dendritic cells lacking pentalaminar structures (Birbeck granules). CONCLUSION: JXGs of the oral cavity vary in their clinical and histopathologic appearances and necessitate that Langerhans' cell disease (LCD) be excluded. JXG and Langerhans' cell disease may occur concurrently, before or after each other, in some children.