CD56 expression of neuroendocrine neoplasms on immunophenotyping by flow cytometry

Abstract

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.

Amelanotic Malignant Melanoma of Unknown Primary Origin Metastasizing to the Bone Marrow: A Case Report and Review of the Literature

“…CD56 is a cell adhesion protein called NCAM1 (neural cell adhesion molecule 1) that is known to be expressed in hematological malignancies, such as NK/T cell neoplasms, malignant myeloma and some cases of acute leukemia. However, CD56 is also expressed in some nonhematological malignancies, such as melanoma (17), small cell carcinoma (18), rhabdomyosarcoma (19), Merkel cell carcinoma (20), neuroblastoma (21) and neuroendocrine tumors/carcinoma (22).…”

“…Farionla et al evaluated the CD56 expression in neuroendocrine tumors obtained from fine-needle aspiration biopsy specimens and reported the utility of the CD56 expression in the absence of lymphoid antigens for specifically diag-nosing neuroendocrine tumors (22). On the other hand, few reports regarding the usefulness of FCM in diagnosing malignant melanoma have been published.…”

Is the Tumor Infiltrating Natural Killer Cell (NK-TILs) Count in Infiltrating Ductal Carcinoma of Breast Prognostically Significant?

“…Its over expression in malignant cells is linked with an aggressive tumor type, insufficient therapeutic response, and a reduced survival time in different malignancies including lymphoblastic and myeloid leukemias (ALLs/AML), malignant melanoma (Johnson, 1999;Abbott et al, 2004), and different cancers (Pujol et al, 1993;Zoltowska et al, 2001;Daniel et al, 2003Choi et al, 2004Cho et al, 2006;Evans et al, 2006;). It has been reported in different types of epithelial malignancies and sarcomas like Ewings /PNET (McKenzie et al, 1981;Lipinski et al, 1987;Gardner et al, 1998;Farinola et al, 2003).…”

Excellent Prognosis in a Subset of Patients with Ewing Sarcoma Identified at Diagnosis by CD56 Using Flow Cytometry

“…CD56 is expressed in a wide spectrum of neoplasms including epithelial neoplasms, some cases of ES and PNET (23)(24)(25)(26). FC using CD99, CD56, and CD45 has been used to evaluate ES tumor samples by applying the profile CD99þ/ CD45À and CD99þ/CD56þ/CD45À (24,27).…”