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CD56 expression of neuroendocrine neoplasms on immunophenotyping by flow cytometry
Author(s) -
Farinola Maryam A.,
Weir Edward G.,
Ali Syed Z.
Publication year - 2003
Publication title -
cancer cytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.052
H-Index - 304
eISSN - 1097-0142
pISSN - 0008-543X
DOI - 10.1002/cncr.11458
Subject(s) - pathology , medicine , immunophenotyping , cytopathology , fine needle aspiration , merkel cell carcinoma , population , immunoperoxidase , biopsy , carcinoma , antigen , cytology , antibody , immunology , environmental health , monoclonal antibody
BACKGROUND CD56 antigen or NCAM (neural cell adhesion molecule) has an established role in the diagnosis of non‐Hodgkin lymphoma (NHL)‐natural killer cell type and other hematologic malignancies. Therefore, it is included routinely in the panel of antibodies for flow cytometric (FC) analysis of suspected lymphomatous tissue specimens obtained from fine‐needle aspiration biopsy (FNAB). The authors evaluated the role of CD56 expression on FC of neuroendocrine (NE) tumors. An initial diagnosis of NHL was suspected based on an on‐site FNAB evaluation. METHODS Ten FNABs were identified from the cytopathology files at The Johns Hopkins Hospital, Baltimore, MD (2000–2001). Flow cytometric analysis was negative for NHL but revealed a CD56‐positive nonlymphoid cell population. An FNAB evaluation was performed on air‐dried Diff‐Quik–stained smears and FC analysis used a fixed panel of 12 antibodies (B‐cell markers, T‐cell markers, CD33, CD56, and CD71). Immunoperoxidase staining (IPOX) was performed on the cell block sections from four of the tissue specimens using epithelial and NE markers, CD56, desmin, and O13 antibodies. Sites of FNAB included the lung (five cases), liver (one case), lymph node (three cases), and peritoneum (one case). Only one patient had a history of cancer at the time of FNAB. RESULTS All cytologic diagnoses were confirmed by histopathologic follow‐up on resection or biopsy or both. Diagnoses included small cell carcinoma (eight cases), Merkel cell carcinoma (one case), and primitive neuroectodermal tumor/Ewing sarcoma (one case). All tissue specimens that underwent IPOX stained strongly with NE markers, with one tissue section staining only with O13. CONCLUSIONS CD56 expression by FC in the presence of negative immunostaining with lymphoid markers represented a unique yet highly specific method for the diagnosis of NE tumors by FNAB. This procedure eliminated the need for further IPOX studies on the already limited cytologic sample and provided a timely and accurate diagnosis. Cancer (Cancer Cytopathol) 2003;99:240–6. © 2003 American Cancer Society.