Ewing Sarcoma With Extensive Neural Differentiation
Ewing Sarcoma With Extensive Neural Differentiation
Objectives: Three patients with Ewing sarcomas showing extensive neural differentiation are presented.
Methods: The patients were two women and one man between the ages of 15 and 35 years. Anatomically, one tumor was in the lung, one in the testis, and one in the cervix uteri. The symptoms were determined by the location of the neoplasm and included respiratory symptoms, testicular pain, and pelvic manifestations, respectively. Complete surgical resection of the tumors was performed.
Results: Histologically, all neoplasms showed similar characteristics—namely, a neoplastic cellular proliferation arranged in sheets and composed of small blue cells with round to oval nuclei and inconspicuous nucleoli typical for Ewing sarcoma. In addition, in two cases, there were areas characterized by the presence of neuropil, ganglion cells, and small cells most compatible with ganglioneuroblastoma, while in one tumor, the neural component was characterized by the presence of small cells with prominent perivascular pseudorosettes more closely resembling ependymoma. Immunohistochemical studies in all cases and molecular analysis in two tumors were in keeping with a diagnosis of Ewing sarcoma.
Conclusions: The recognition of such histologic variants is important in the diagnostic assessment of these tumors to avoid misinterpretation, especially in small biopsy specimens.
Ewing sarcoma is the current acceptable nomenclature for a group of tumors that, over the years, have received different designations, including primitive neuroectodermal tumors, neuroepithelioma, small round cell tumors of the thoracopulmonary region, and Askin tumor. Most of these tumors occur in the bone or soft tissue; Ewing sarcoma occurring outside of those areas can be considered real rarities in tumor pathology. Nevertheless, the latter have been well documented in the literature, and Ewing sarcomas have been described in unusual areas such as the testis, cervix uteri, and lung, among others. Therefore, the cases presented in this study do not represent a novelty in terms of anatomic location, but the fact that these three neoplasms contained an additional tumor component characterized by extensive areas of neural differentiation in keeping with the histologic features of ganglioneuroblastoma or ependymoma. In this context, it is important to point out that none of our patients had received any medical treatment prior to surgical resection of their tumors. This report highlights the occurrence of prominent neural differentiation in Ewing sarcoma and discusses the possible implications with regard to diagnostic accuracy in small biopsy samples as well as the potential role of such a phenomenon for the clinical outcome.
Abstract and Introduction
Abstract
Objectives: Three patients with Ewing sarcomas showing extensive neural differentiation are presented.
Methods: The patients were two women and one man between the ages of 15 and 35 years. Anatomically, one tumor was in the lung, one in the testis, and one in the cervix uteri. The symptoms were determined by the location of the neoplasm and included respiratory symptoms, testicular pain, and pelvic manifestations, respectively. Complete surgical resection of the tumors was performed.
Results: Histologically, all neoplasms showed similar characteristics—namely, a neoplastic cellular proliferation arranged in sheets and composed of small blue cells with round to oval nuclei and inconspicuous nucleoli typical for Ewing sarcoma. In addition, in two cases, there were areas characterized by the presence of neuropil, ganglion cells, and small cells most compatible with ganglioneuroblastoma, while in one tumor, the neural component was characterized by the presence of small cells with prominent perivascular pseudorosettes more closely resembling ependymoma. Immunohistochemical studies in all cases and molecular analysis in two tumors were in keeping with a diagnosis of Ewing sarcoma.
Conclusions: The recognition of such histologic variants is important in the diagnostic assessment of these tumors to avoid misinterpretation, especially in small biopsy specimens.
Introduction
Ewing sarcoma is the current acceptable nomenclature for a group of tumors that, over the years, have received different designations, including primitive neuroectodermal tumors, neuroepithelioma, small round cell tumors of the thoracopulmonary region, and Askin tumor. Most of these tumors occur in the bone or soft tissue; Ewing sarcoma occurring outside of those areas can be considered real rarities in tumor pathology. Nevertheless, the latter have been well documented in the literature, and Ewing sarcomas have been described in unusual areas such as the testis, cervix uteri, and lung, among others. Therefore, the cases presented in this study do not represent a novelty in terms of anatomic location, but the fact that these three neoplasms contained an additional tumor component characterized by extensive areas of neural differentiation in keeping with the histologic features of ganglioneuroblastoma or ependymoma. In this context, it is important to point out that none of our patients had received any medical treatment prior to surgical resection of their tumors. This report highlights the occurrence of prominent neural differentiation in Ewing sarcoma and discusses the possible implications with regard to diagnostic accuracy in small biopsy samples as well as the potential role of such a phenomenon for the clinical outcome.
