Role of immunohistochemistry in the diagnosis of malignant small round cell tumors

Abstract

Background: Immunohistochemistry is a key tool for the analysis of localization of target molecules within tissues. It has a significant role in the identification of tumors lacking evidence of lineage differentiation on the basis of routine light microscopic morphology alone. Approximately 90% of tumors posing diagnostic difficulties by morphology could be accurately classified by exploiting immunohistochemistry. The aim of this study is to identify the true identity of malignant small round cell tumors by immunohistochemical analysis. Materials and Methods:This was a retrospective study done in Department of Histopathology of B.P.Koirala Memorial Cancer Hospital from January 2010 to April 2011.A total of 40 cases small round cell tumors were selected for immunostaining. The immunohistochemistry technique used is the Polymer detection-EnvisionTM System, a two step staining technique based on Horse Radish Peroxidase labeled dextran polymer technology (DAKO Company). Results: Out of 40 cases of malignant small round cell tumors, there were 21 cases (52.5%) of Non- Hodgkin Lymphoma , 11 cases (27.5%) of Ewing’s Sarcoma/Primitive Neuroectodermal Tumor, 1 case (2.5%) of Lymphoblastic Lymphoma , 1 case (2.5%) of Rhabdomyosarcoma, 2 cases (5%) of Low grade neuroendocrine tumor, 1 case (2.5%) of Neuroblastoma, 2 cases (5%) of Poorly differentiated Synovial Sarcoma (small cell variant), 1case (2.5%) of Malignant Melanoma (small cell variant). Conclusion: Immunohistochemistry is a valuable adjunct to routine hematoxylin and eosin staining for adequate and accurate categorization of malignant small round cell tumors. Keywords: Immunohistochemistry; Malignant Small Round Cell Tumor; Non Hodgkin’s Lymphoma; Ewing’s Sarcoma; Rhabdomyosarcoma DOI: http://dx.doi.org/10.3126/jpn.v1i2.5398 JPN 2011; 1(2): 87-91

Evaluation of a Panel of Ihc Markers in Differentiation of Extranodal Malignant Small Round Cell Tumors.

“…Neuroblastoma shows immunoreactivity with NSE, synaptophysin and chromogranin. 2 Our findings are consistent with the study conducted by Patel MM et al 11 .…”

“…It is therefore, imperative to determine whether the small round cell tumor is epithelial, mesenchymal, neuroendocrine, melanocytic or hematopoietic in nature for treatment purposes as well as for the prognostic evaluation of the tumor. 2 Several monoclonal antibodies have been developed, that detect different epitopes of the antigens which are present in the tumor cells. However, there is no antibody which is specific for a single tumor type and the pathologist has to judiciously correlate the clinical, radiological and the morphological findings with a panel of immumohistochemical (IHC) markers.…”

Role of immunohistochemistry in the differential diagnosis of malignant small round cell tumor: a study of 38 cases

“…In more than 90% cases accurate diagnosis is made with the help of IHC along with routine H & E stain, but remaining cases require help of other ancillary technique like molecular or genetic study. [1][2][3][4] For treatment purposes, it is crucial to determine whether an undifferentiated neoplasm is epithelial, mesenchymal, or hematopoietic. Treatment may include surgery, radiotherapy, chemotherapy, hormone therapy or a combination.…”

The role of immunohistochemistry for diagnosing undifferentiated malignancy in the head and neck region

“…Histopathological differentiation of undifferentiated carcinoma from neuroendocrine carcinoma is challenging and is significantly aided by immunohistochemistry. 14,15 Our results showed diagnostic guidance in over 90% patients. It was not possible in 2 patients (5.7%) of cases.…”