Clinicopathological and EBV analysis of respiratory epithelial adenomatoid hamartoma.

BACKGROUND: To investigate the clinicopathological characteristics of respiratory epithelial adenomatoid hamartoma (REAH) in residents of Southern China and to study the correlation between REAH and Epstein-Barr virus (EBV). METHODS: Clinicopathological data of 53 cases of REAH were retrospectively analyzed. The immunoreactivity for CK 7, CK20, CEA, p53, and Ki-67, Alcian blue-periodic acid-Schiff (AB-PAS) staining and in situ hybridization for EBV-encoded RNA (EBER) were carried out. RESULTS: REAH lesions were covered with ciliated columnar epithelium and proliferation of subepithelial glands, which were positive for CK7, and negative for CK20, CEA, and p53. Goblet cell metaplasia was stained blue by AB-PAS. The frequency of EBER positive cases in REAH located in nasopharynx was 27.78%, compared with that in the nasal cavity (15.79%) and paranasal sinuses (12.50%), there were no statistical differences. CONCLUSIONS: REAH is an uncommon entity with distinctive morphologic features and EBV may have nothing to do with REAH. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here:http://www.diagnosticpathology.diagnomx.eu/vs/5875687401178748.

Splenic vascular tumors: a histologic, immunophenotypic, and virologic study.

Vascular tumors of the spleen include several different entities, some of which are unique to that organ. Twenty-two such proliferations were studied, including 10 hemangiomas, six littoral cell angiomas, four angiosarcomas, and two hamartomas. The hemangiomas included seven with localized tumors and three with diffuse angiomatosis of the spleen. All cases were studied by paraffin section immunohistochemistry with a large panel of antibodies. In addition, all cases were studied for the presence of the Kaposi's sarcoma-associated herpesvirus (KSHV) using the polymerase chain reaction. The morphologic findings were similar to those previously reported. All proliferations were vimentin positive, and one angiosarcoma was focally keratin positive. All cases reacted for CD31, whereas 20 of 22 were positive for von Willebrand's factor and 19 of 22 were positive for Ulex europeaus. CD34 expression in lining cells was identified in 10 of 10 hemangiomas, two of four angiosarcomas, and one of two hamartomas, whereas all six cases of littoral cell angioma were negative. CD68 was expressed in all cases of littoral cell angioma but was also positive in all three diffuse hemangiomas, two of seven localized hemangiomas, and two of four angiosarcomas. CD21 expression was restricted to the lining cells of littoral cell angioma, and CD8 expression was only identified in two of two hamartomas and two of four angiosarcomas. KSHV was not detected in any of the cases. These findings suggest that there are distinct immunophenotypic as well as morphologic features of splenic vascular tumors. Littoral cell angiomas have a characteristic CD34-/CD68+/CD21+/CD8- immunophenotype and hamartomas have a characteristic CD68-/CD21-/CD8+ phenotype. The frequent CD68 expression in diffuse hemangioma suggests an immunophenotypic difference from localized hemangioma of the spleen.

Role of cytology in the intraoperative diagnosis of HIV-positive patients undergoing stereotactic brain biopsy.

OBJECTIVE: To determine the accuracy of cytology in the intraoperative diagnosis of central nervous system (CNS) lesions in human immunodeficiency (HIV)-positive patients. STUDY DESIGN: We prospectively studied 75 cases of computed tomography- or magnetic resonance imaging-guided brain biopsies performed with stereotactic instrumentation and a Nashold biopsy cannula over the course of five years. Biopsy samples were sent for both frozen section and immediate cytologic evaluation. Crush preparations (Papanicolaou and Diff-Quik stained) were used for cytologic assessment. There were 23 cases of progressive multifocal leukoencephalopathy (PML), 8 of toxoplasmosis (toxo), 3 of herpes simplex virus, 26 of lymphoma, 3 of HIV encephalitis, 1 of melanoma, 1 of hamartoma and 10 of nonspecific changes (paraffin section). RESULTS: Using permanent hematoxylin and eosin-stained histologic sections as the "gold standard," frozen section had a sensitivity of 78% and a specificity of 90%, while cytology had a sensitivity of 88% and specificity of 90%. Most of the false negative cases in cytology and frozen section were due to the predominance of necrosis and/or gliosis, present in six cases of toxo. Two of the false positive cases in frozen section (diagnosed as lymphoma) showed toxo, while two false positive cases in cytology (diagnosed as PML) showed only gliosis with negative immunoperoxidase staining for PML in the permanent sections. CONCLUSION: First, cytology had higher sensitivity that frozen section. Second, cytology provided faster results in most instances, primarily due to the nature of specimen preparation. Third, most misdiagnoses occurred in infectious diseases, especially toxo; this should therefore be kept in mind when nonspecific changes with an atypical lymphocytic infiltrate are seen. Fourth, cytology can be an alternative to frozen section for the intraoperative diagnosis of CNS lesions in HIV-positive patients. Another advantage of cytology is elimination of the need for cutting potentially infectious fresh tissue.