[450] Perivascular Mesenchymal Cell Clusters on Imprint Cytology of Lymph Nodes.

Tomoko Wakasa, Miyuki Noda, Masayuki Shintaku, Masahiko Ohsawa, Kenichi Wakasa. Osaka Red Cross Hospital, Japan; Osaka City University, Graduate School of Medicine, Japan

Background: In stump cytology specimens of lymph nodes, other than lymphocytes, there are many mesenchymal cells, for example, tingible body macrophages, eosinophils, follicular dendritic cells, interdigitating cells, or fragments of capillary vessels, in the background. Furthermore, sometimes, large mesenchymal cell clusters are observed in the cytological specimen. The clusters are composed of smooth muscle actin-positive spindle cells and CD34-positive endothelial cells. We have termed these spindle cells Perivascular Mesenchymal Cell Clusters (PVMCCs). In this study, we investigated the clinical significance of PVMCCs in the imprint cytology of lymph nodes.
Design: Cases involved 144 imprint specimens of lymph nodes, 67 cases of B-cell lymphoma, 17 cases of T-cell lymphoma, 17 cases of Hodgkin lymphoma, 38 cases of reactive lymphoid hyperplasia, and 5 cases of Castleman disease.Two consecutive slides were prepared from each biopsy specimen. The slides were immediately fixed in 95% ethanol and stained using the standard Papanicolaou method. After cytomorphological evaluation, immunocytochemical staining was performed for SMA or CD34 on the destained Papanicolaou slides.
Results: In the core of the PVMCCs, CD34-positive spindle cells with ovoid nuclei and pale chromatin were seen. In some cases, the CD34-positive spindle cells were shaped like small, elongated vessels. Around the CD34-positive cells, there were many SMA-positive cells with poorly defined cytoplasmic boundaries, spindle-shaped nuclei, and dense chromatin. PVMCCs were found in 11 of the 67 cases of B-cell lymphoma, in 13 of the 17 cases of T-cell lymphoma, and 8 of the 17 cases of Hodgkin lymphoma. In particular, PVMCCs were found in 5 of the 6 cases of Angioimmunoblastic T-cell lymphoma. However, for non-tumorous lesions, capillary vessels are found in some cases, but PVMCCs were seen in only 3 of the 38 cases of reactive lymphoid hyperplasia. No PVMCCs was observed in the cases of Castleman disease.
Conclusions: PVMCCs were observed in 76% of T-cell lymphoma and 47% of Hodgkin lymphoma, but rarely observed in reactive lymphoid hyperplasia. (7%) It may be useful to differentiate between malignant T-cell lymphoma and reactive lymphoid hyperplasia.
Category: Cytopathology

Wednesday, March 2, 2011 1:00 PM

Poster Session VI # 84, Wednesday Afternoon

 

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