Epithelial marker expression does not rule out a diagnosis of Ewing’s sarcoma family of tumours

Abstract

Epithelial marker expression has been reported in Ewing's sarcoma family of tumors (ESFT). However, cytokeratin (CK), epithelial membrane antigen (EMA), and carcino embryonic antigen (CEA) prevalence has not been assessed thoroughly in a large series of genetically confirmed ESFT. The aim of the present study is to confirm the presence of epithelial markers in a large group of ESFT tested genetically for any of their specific gene fusions and the differential diagnosis with other small round cell tumors. To establish the prevalence of epithelial markers, we then performed immunohistochemical studies with antibodies CK (AE1/AE3), CK8/18, CK34β12, EMA, E-cadherin, and CEA on 415 genetically confirmed ESFT. Immunoreactivity to cytokeratin, EMA, and CEA was present in 19.2%, 6.6%, and 20.8% of cases, respectively. There was no significant association between epithelial markers and histological subtypes, but the atypical variant of ESFT expressed these markers in a high proportion compared with the peripheral neuroectodermal tumors and the conventional variant. The present findings confirm that epithelial marker expression in ESFT, including EMA and CEA, does not rule out a diagnosis of ESFT, and the integration of clinical, radiological, histopathological, immunohistochemical, and molecular genetic findings should form the basis for the diagnosis of bone and soft tissue sarcomas, especially in tumors with atypical or unusual phenotype.

Carcinoma of the Thyroid With Ewing Family Tumor Elements and Favorable Prognosis

“…During the study of the present case, we realized that the small cell carcinoma of the thyroid reported by Cruz et al, 12 which had a favorable clinical course (38 months of followup), was morphologically and immunohistochemically We admit that the distinction between CEFTE and PEEFT with prominent epithelial differentiation [13][14][15] is not clear cut. Nevertheless, the particular favorable evolution 5 The thyroid PEEFT of the thyroid reported by Adapa et al 6 was diagnosed in a 9-yearold child who remained free of disease for at least 6 years after chemotherapy with standard arm of COG-AEWS0031 Ewing sarcoma treatment protocol and right lobectomy plus isthmectomy.…”

“…12 This unique epithelial tumor, which showed neither C-cell nor follicular cell differentiation, coexisted with papillary thyroid carcinoma (PTC) foci and diffusely expressed cytokeratins and p63, in the absence of vimentin. 12 Since the identification of the expression of cytokeratins in up to 46% of PEEFTs, 13,14 the occurrence of epithelial differentiation in a small cell malignant tumor is no longer a synonym of small cell carcinoma. 14,15 In thyroid, only 3 cases of primary PEEFT 5-7 and 1 case of secondary PEEFT mimicking a thyroid nodule 16 have been described to date.…”

Ewing sarcoma family of tumours: unusual histological variants and immunophenotypic characteristics

“…25 CK19 and EMA expression is uncommon (14.8% and 6.6% respectively). 27,39 Variable expression of tight junction markers such as claudin-1 (63%), zonula-occludens-1 (51%) and occludin (11%) has been reported in ESFT. 42 E-cadherin is negative with the 36B5 clone which targets the extracellular domain.…”

Biomarkers of Osteosarcoma, Chondrosarcoma, and Ewing Sarcoma

“…Machado et al (2011) assessed, by genetic analysis, the role of epithelial markers in Ewing’s tumor; the author to show the presence of epithelial markers used antibiotics and an immunohistochemical study in tumor cells. The authors say a statistically significant relationship between the expression of the markers and epithelial cell variants of the tumor is not present, even if they claim that an increased expression is present in these tumors and therefore can be regarded in the diagnosis of the disease (Machado et al, 2011).…”

“…The authors say a statistically significant relationship between the expression of the markers and epithelial cell variants of the tumor is not present, even if they claim that an increased expression is present in these tumors and therefore can be regarded in the diagnosis of the disease (Machado et al, 2011). …”