Vascular alterations in schwannoma.

Schwannomas or neurilemmoma are benign peripheral nerve sheath tumors, which most frequently occur at the cerebellopontine angle. This morphologic study examines vascular alterations in these tumors, comparing them to other benign spindle cell neoplasms of the nervous system, while correlating these findings with evidence of vascular permeability. Thirty-four nervous system spindle cell neoplasms, sixteen schwannomas, nine fibroblastic/transitional meningiomas and nine peripheral neurofibromas were stained with H&E, Prussian-blue stain, and immunoreacted for factor VIII-related antigen and interstitial albumin.

Identification of unsuspected PNH-type cells in flow cytometric immunophenotypic analysis of peripheral blood and bone marrow.

In this report, the flow cytometric expression patterns for CD14 on monocytic cells and CD16 on granulocytic cells in peripheral blood or bone marrow specimens are illustratedfor 15 patients proven to have a paroxysmal nocturnal hemoglobinuria (PNH) phenotype by flow cytometric analysis for CD55 and CD59. The varied clinical manifestations of PNH and its rarity may make it difficult to recognize clinically. As a result, blood or bone marrow samples may be submitted for flow cytometric analysis to exclude bone marrow neoplasia or dysplasia in patients with cytopenias rather than to exclude PNH.

Natural killer-like T-cell lymphoma of the parotid in a patient infected with human immunodeficiency virus.

A 42-year-old man with acquired immunodeficiency syndrome developed a mass of the right parotid gland and multiple hepatic masses. Hematoxylin-eosin-stained sections of the parotid lesion showed a diffuse infiltrate of large mononuclear cells with vesicular nuclei and prominent nucleoli, consistent with a non-Hodgkin lymphoma. Immunohistochemical stains demonstrated expression of the T-cell markers CD3 and UCHL-1, as well as latent membrane protein 1 and T-cell intracellular antigen 1.