The spectrum of the cytopathological features of primary effusion lymphoma and human herpes virus 8‐related lymphoproliferative disorders

Abstract

Introduction: Human herpes virus 8-related lymphoproliferative disorders are a complex and heterogeneous group of entities and some of them are eminently diagnosed by cytopathology. In a routine laboratory, these lesions account for less than 1% of the effusion fluids samples. However, they represent up to 30% of all the lymphoma diagnosis from effusion cytological samples and their consideration in the diagnostic flow chart is mandatory, especially in human immunodeficiency virus-positive patients. Methods: A retrospective series of cytological specimens from cavity effusions (n = 605) were analysed. Five human herpes virus 8-related lymphoproliferative processes were recruited. A combination of morphological criteria (enhanced with May-Grünwald Giemsa staining), cell block-based immunocytochemistry and flow cytometry were undertaken for final characterisation. Results: The identification of malignant cells may be difficult. Some specimens are particularly rich, easily leading to suspect a lymphoproliferative process, whereas in other cases, the presence of abundant reactive mesothelial cells, histiocytes, neutrophils, small reactive T and B lymphocytes may obscure the neoplastic process. The biological behaviour may be very heterogeneous and a standardised therapy for these cases is still lacking, although some patients may benefit from antiretroviral therapy in a human immunodeficiency virus setting. Conclusions: The present case series highlights some characteristic findings of these entities to reaffirm useful cytopathological diagnostic criteria, stressing the crucial role of the appropriate technical processing of effusion fluids to obtain the best performances.

Cytopathology of bronchoalveolar lavages in COVID‐19 pneumonia: A pilot study

“…The obtained cytocentrifugates were then stained with both May‐Grünwald‐Giemsa and Papanicolaou stains. From the formalin‐fixed aliquot, cell blocks were prepared as previously described 12 . Diagnostic cytocentrifugation (cytospin) and hematoxylin‐eosin–stained sections were examined by a joint panel of lung pathologists (F.P., F.B., and F.F.).…”

“…From the formalin-fixed aliquot, cell blocks were prepared as previously described. 12 Diagnostic cytocentrifugation (cytospin) and hematoxylin-eosin-stained sections were examined by a joint panel of lung pathologists (F.P., F.B., and F.F.). The differential cell count (lymphocytes, neutrophils, eosinophils, mast cells, plasma cells, macrophages, and multinucleated giant cells [MGCs]) was determined with the May-Grünwald-Giemsa-stained cytospin after the assessment of 200 cells at ×400 magnification in random fields; pure numbers were recorded and then turned into percentages based on the total number of cells counted.…”

Primary Effusion Lymphoma: A Timely Review on the Association with HIV, HHV8, and EBV

“…The spectrum of HHV8-positive lymphoproliferative disorders is broad, ranging from reactive lymphoproliferation, multicentric Castleman disease, classic PEL, HHV8-positive large B-cell lymphoma, to HHV8-positive germinotropic lymphoproliferative disorder, often with overlapping features among different HHV8-positive diseases [41][42][43]. Classical PEL as currently defined in the WHO classification scheme occurs usually in HIV-positive patients with lymphomatous effusion cells positive for HHV8, indicating that HHV8 infection plays a key role in lymphomagenesis [44].…”