Cytopathology in the diagnostic appraisal of uncommon malignant neoplastic lesions.

Cytology and fine needle aspiration (FNA) cytology are accepted means of diagnosing and typing of common forms of malignant tumors. However, their usefulness for diagnosing less common neoplasms is not clearly established and this study was designed to examine this. We report four unusual cases of patients with malignant neoplasms in which cytology and fine needle aspiration cytology or aspiration biopsy (FNAC, FNAB) contributed significantly in establishing the diagnosis. These cases facilitate the diagnostic capabilities of cytology over a wide spectrum of neoplasms including rare lymphoproliferative disorders and carcinomas.

HHV-8-positive and EBV-positive intravascular lymphoma: an unusual presentation of extracavitary primary effusion lymphoma.

Intravascular lymphomas are rare and aggressive hematolymphoid tumors. Here, we describe a human herpesvirus type-8 (HHV-8)/Kaposi sarcoma-associated herpesvirus-positive and Epstein-Barr virus (EBV)-positive intravascular lymphoma. The patient was a 59-year-old human immunodeficiency virus-positive man who presented with diarrhea, abdominal pain, fevers, night sweats, and weight loss. Radiographic studies of the abdomen and pelvis revealed numerous subcentimeter nodules within the subcutaneous fat that lacked connection to the skin. An excisional biopsy demonstrated large atypical cells within vessels in the deep subcutaneous fat, and many of the vessels contained extensive organizing thrombi. The atypical cells lacked strong expression of most B-cell markers but were positive for MUM-1 and showed partial expression of several T-cell markers. An immunohistochemical stain for HHV-8 and an in situ hybridization for EBV were both positive in the neoplastic cells. The disease had a rapidly progressive and fatal course. This lymphoma appears to represent an entirely intravascular form of primary effusion lymphoma and highlights the propensity for HHV-8 and EBV-positive lymphoid neoplasms to show aberrant expression of T-cell markers, illustrates the utility of skin biopsies for the diagnosis of intravascular lymphoma, and suggests that biopsies to evaluate for intravascular lymphoma should be relatively deep and include subcutaneous fat.

Primary effusion lymphoma-like lymphoma in a patient with inflammatory bowel disease.

A 77-year-old man with inflammatory bowel disease (IBD) and who was treated with anti-tumor necrosis factor (TNF), 6-mercaptopurine and corticosteroids, presented with primary effusion lymphoma-like lymphoma (PEL-like lymphoma) with massive ascites. The patient's clinical course was complicated by acute renal insufficiency and hypotension, which led to death within 2 wk. In general, patients with IBD may have an increased risk for development of lymphoma, which is frequently associated with immunosuppressive and/or anti-TNF antibody therapies. PEL is a rare subset of lymphoma localized to serous body cavities, lacks tumor mass or nodal involvement, and is associated with infection by human herpes virus 8 (HHV-8). Primary neoplastic effusion may also be present in patients with large B-cell lymphoma without evidence of human immunodeficiency virus or HHV-8 infections. This type of lymphoma is classified as PEL-like lymphoma. Both PEL and PEL-like lymphoma types have been reported in patients undergoing immunosuppressive therapy, but to the best of our knowledge, the case described herein represents the first PEL-like lymphoma occurring in a patient with IBD.

Notch1 in primary effusion lymphoma: a clinicopathological study.

Primary effusion lymphoma is a human herpes virus 8 (HHV-8)-associated large cell lymphoma of body cavities. Detailed large-scale clinicopathological studies are rarely reported, and the underlying mechanism of lymphomagenesis remains elusive. In the present report, we studied the clinicodemographic, immunophenotypic, and cytomorphological features on a cohort of 12 cases of primary effusion lymphoma. In contrast to HHV-8, which was positive in all nine cases tested (100%), HIV was found in 75% (9/12) of cases, whereas the three HIV-negative cases were either in elderly patients (one with hepatitis C virus infection and one with asbestoses exposure) or in a heart transplantation recipient. By flow cytometry, the antigens expressed in descending order were CD38, CD71, HLA-DR, CD30, and CD45RO. B-cell markers were largely negative. Cytomorphologically, all cases showed atypical to anaplastic morphology. Notch1, a member of transmembrane signal transduction family, was found in six of seven HHV-8-positive cases (86%). In agreement with in vitro studies using human primary effusion lymphoma cell lines, we have found that Notch1 was expressed in the majority of HHV-8-positive primary effusion lymphoma cases, corroborating the notion that Notch1 may have an important role in HHV-8-mediated lymphomagenesis of primary effusion lymphoma.