![[PDF]](/pb-assets/Icons/adobe-pdf-icon-1498649896243.png){kind=icon}
Abstract
Ewing’s sarcoma/primitive neuroectodermal tumor (PNET) has been the subject of recent reports describing morphologic variants (adamantinoma-like, large cell, spindle cell, sclerosing, clear cell, and vascular-like) of the most classic form, as well as cases displaying unusual morphologic differentiation and atypical immunohistochemical features. We report a case of an uncommon lung tumor in a 20-year-old female, morphologically and molecularly consistent with an Ewing’s sarcoma/PNET tumor with foci of squamous differentiation, and peculiar expression of vimentin, high-molecular-weight keratins, p63, synaptophysin, and chromogranin. This case raises a challenging differential diagnostic problem with therapeutic implications: Should the patient be treated following the protocols for Ewing’s sarcoma/PNET tumors or as for lung carcinoma with neuroendocrine features? The patient we report here was treated with neoadjuvant chemotherapy for Ewing’s sarcoma/PNET according to Euro Ewing 99 study protocol followed by surgery and has no evidence of disease 15 months after the initial diagnosis. This highlights the importance of achieving the correct diagnosis of these atypical tumors using all clinical, morphological, and ancillary methods available to allow for their correct and timely treatment.
References
| 1. |
Steiner, GG, Jundt, G., Martignetti, JA. Pathology and genetics of tumours of soft tissue and bone. In: Fletcher, C, Unni, KK, Mertens, F, eds. World Health Organization Classification of Tumours. Lyon, France: IARC Press; 2002:297-300. Google Scholar |
| 2. |
Delattre, O, Zucman, J, Plougastel, B. Gene fusion with an ETS DNA-binding domain caused by chromosome translocation in human tumors. Nature. 1992;359:162-165. Google Scholar | Crossref | Medline | ISI |
| 3. |
Zucman, J, Delattre, O, Desmaze, C. Cloning and characterization of the Ewing’s sarcoma and peripheral neuroepithelioma t(11;22) translocation breakpoints. Genes Chromosomes Cancer. 1992;5:271-277. Google Scholar | Crossref | Medline | ISI |
| 4. |
Lombart-Bosch, A, Machado, I, Navarro, S. Histological heterogeneity of Ewing’s sarcoma /PNET: an immunohistochemical analysis of 415 genetically confirmed cases with clinical support. Virchows Arch. 2009;455:397-411. Google Scholar | Crossref | Medline | ISI |
| 5. |
Wu, H-T, Govender, D. Ewing sarcoma family of tumours: unusual histological variants and immunophenotipyc characteristics. Diagn Histopathol. 2012;18:348-355. Google Scholar | Crossref |
| 6. |
Machado, I, Navarro, S, López-Guerrero, Alberghini, M, Picci, P, Lombart-Bosch-A. Epithelial marker expression does not rule out a diagnosis of Ewing’s sarcoma family tumours. Virchows Arch. 2011;459:409-414. Google Scholar | Crossref | Medline | ISI |
| 7. |
Folpe, AL, Goldblum, JR, Rubin, BP. Morphologic and immunophenotipyc diversity in Ewing family tumours: a study of 66 genetically confirmed cases. Am J Surg Pathol. 2005;29:1025-1033. Google Scholar | Medline | ISI |
| 8. |
Weinreb, I, Goldstein, D, Perez-Ordoñez, B. Primary extraskeletal Ewing family tumor with complex epithelial differentiation: a unique case arising in the lateral neck presenting with Horner syndrome. Am J Surg Pathol. 2008;32:1742-1748. Google Scholar | Crossref | Medline | ISI |
| 9. |
Gu, M, Antonescu, CR, Guiter, G, Huvos, AG, Ladanyi, M, Zakowski, MF. Cytokeratin immunoreactivity in Ewing sarcoma: prevalence in 50 cases confirmed by molecular diagnostic studies. Am J Surg Pathol. 2000;24:410-416. Google Scholar | Crossref | Medline | ISI |
| 10. |
Vakar-Lopez, F, Ayala, AG, Raymond, AK, Czerniak, B. Epithelial phenotype in Ewing’s sarcoma/primitive neuroectodermal tumor. Int J Surg Pathol. 2000;8:59-65. Google Scholar | SAGE Journals | ISI |
| 11. |
Wick, MR . Immunohistology of neuroendocrine and neuroectodermal tumors. Semin Diagn Pathol. 2000;17:194-203. Google Scholar | Medline | ISI |
| 12. |
Pagani, A, Macrí, L, Rosolen, A, Toffolatti, L, Stella, A, Bussolati, G. Neuroendocrine differentiation in Ewing’s sarcomas and primitive neuroectodermal tumors revealed by reverse transcriptase-polymerase chain reaction of chromogranin mRNA. Diagn Mol Pathol. 1998;7:36-43. Google Scholar | Crossref | Medline |
| 13. |
Chan, JM, Bilodeau, E, Celin, S, Nikiforov, Y, Johnson, JT. Ewing sarcoma of the thyroid: report of 2 cases and review of the literature [published online March 18, 2013]. Head Neck. doi:10.1002/hed.23240. Google Scholar | Crossref | ISI |
| 14. |
Machado, I, Noguera, R, Mateos, EA. The many faces of atypical Ewing’s sarcoma. A true entity mimicking sarcomas, carcinomas and lymphomas. Virchows Arch. 2011;458:281-290. Google Scholar | Crossref | Medline | ISI |
| 15. |
Jacobson, SA . Polyhistioma: a malignant tumor of the bone and extraskeletal tissues. Cancer. 1977;40:2116-2130. Google Scholar | Crossref | Medline | ISI |
| 16. |
Hutter, RV, Foote, FW, Francis, KC, Sherman, RS. Primitive multipotential primary sarcoma of the bone. Cancer. 1966;19:1-25. Google Scholar | Crossref | Medline | ISI |
| 17. |
Ordonez, NG . Desmoplastic small round cell tumor: a histopathological study of 39 cases with emphasis on unusual histopathological patterns. Am J Surg Pathol. 1998;22:1303-1313. Google Scholar | Crossref | Medline | ISI |
| 18. |
Malone, VS, Dobin, SM, Jones, KA, Donner, LR. CD99 positive large cell neuroendocrine carcinoma with rearranged EWSR1 gene in an infant: cases of prognostically favorable tumor. Virchows Arch. 2010;457:389-395. Google Scholar | Crossref | Medline | ISI |
| 19. |
Brandal, P, Panagopoulos, I, Bjerkehagen, B. Detection of a t(1;22)(q23;q12) translocation leading to a EWSR1-PBX1fusion gene in a myoepithelioma. Genes Chromosomes Cancer. 2008;47:558-564. Google Scholar | Crossref | Medline | ISI |
| 20. |
Romeo, S, Dei-Tos, AP. Soft tissue tumors associated with EWSR1 translocation. Virchows Arch. 2010;456:219-234. Google Scholar | Crossref | Medline | ISI |
| 21. |
Koodiyedath, B, Owen, A, Walker, J, Suvarna, K, Fisher, P, Yeomanson, D. Non small-cell lung cancer in a 15-year-old non-smoker. J Thorac Oncol. 2012;7:e12-e13. Google Scholar | Crossref | Medline | ISI |
| 22. |
Suárez Antelo, J, Rodríguez García, C, Montero Martínez, C, Verea Hernando, H. Pulmonary Ewing sarcoma/primitive neuroectodermal tumor: a case report and a review of literature. Arch Bronconeumol. 2010;46:44-46. Google Scholar | Crossref | Medline | ISI |
| 23. |
Ichiki, Y, Nagashima, A, Chikaishi, Y, Yasuda, M, Yamamoto, I, Toyoshima, S. Primary pulmonary Ewing’s sarcoma: report of a case. Surg Today. 2012;42:812-815. Google Scholar | Crossref | Medline | ISI |
