# Primary Ewing′s Sarcoma of the Sinonasal Region: A Rare Clinical Encounter **Authors:** Ujjwal Sangroula, Prajeeta Bhandari, Ratan Shah, Prajjwol Luitel, Sadmarg Thakur, Monica Shah, Manoj Tamang PMC · DOI: 10.1155/crip/4920419 · 2026-03-06 ## TL;DR This paper reports a rare case of Ewing's sarcoma in the nasal area of an adult, highlighting the challenges in diagnosing such tumors. ## Contribution The novelty lies in presenting a rare adult case of sinonasal Ewing's sarcoma with detailed diagnostic insights. ## Key findings - Ewing's sarcoma in the sinonasal region is rare, especially in adults. - Accurate diagnosis requires comprehensive histopathological and immunohistochemical analysis. ## Abstract Ewing′s sarcoma (EWS) is a highly aggressive tumor of neuroectodermal origin, rarely occurring in the sinonasal tract, particularly in adults. We report a 27‐year‐old male with long‐standing nasal obstruction, initially misdiagnosed as nasal chondromesenchymal hamartoma. Surgical excision revealed a destructive, vascular sinonasal mass. Histology showed sheets of small round cells within a sclerotic stroma, and immunohistochemistry positivity for CD99, vimentin, cyclin D1, BCL2, and NKX2.2 confirmed EWS. This case underscores the diagnostic difficulty of sinonasal small round cell tumors and the necessity of thorough histopathological and immunohistochemical analysis. ## Linked entities - **Proteins:** CD99 (CD99 molecule (Xg blood group)), PRELID1 (PRELI domain containing 1), ccnd1.S (cyclin D1 S homeolog), BCL2 (BCL2 apoptosis regulator), NKX2-2 (NK2 homeobox 2) - **Diseases:** Ewing's sarcoma (MONDO:0012817) ## Full-text entities - **Genes:** Ewsr1 (Ewing sarcoma breakpoint region 1) [NCBI Gene 14030] {aka Ews, Ewsh}, Des (desmin) [NCBI Gene 13346], CCND1 (cyclin D1) [NCBI Gene 595] {aka BCL1, D11S287E, PRAD1, U21B31}, NKX2-2 (NK2 homeobox 2) [NCBI Gene 4821] {aka NKX2.2, NKX2B}, BCOR (BCL6 corepressor) [NCBI Gene 54880] {aka ANOP2, MAA2, MCOPS2}, CHGA (chromogranin A) [NCBI Gene 1113] {aka CGA, PHE5, PHES}, EWSR1 (EWS RNA binding protein 1) [NCBI Gene 2130] {aka EWS, EWS-FLI1}, Ptprc (protein tyrosine phosphatase receptor type C) [NCBI Gene 19264] {aka B220, CD45R, Cd45, L-CA, Ly-5, Lyt-4}, Erg (ETS transcription factor) [NCBI Gene 13876] {aka D030036I24Rik}, Tle1 (transducin-like enhancer of split 1) [NCBI Gene 21885] {aka C230057C06Rik, Estm14, Grg-1, Grg1, Tle4l}, Cd34 (CD34 antigen) [NCBI Gene 12490], Vim (vimentin) [NCBI Gene 22352], S100a1 (S100 calcium binding protein A1) [NCBI Gene 20193] {aka S100, S100a}, FLI1 (Fli-1 proto-oncogene, ETS transcription factor) [NCBI Gene 2313] {aka BDPLT21, EWSR2, FLI-1, SIC-1}, KIT (KIT proto-oncogene, receptor tyrosine kinase) [NCBI Gene 3815] {aka C-Kit, CD117, MASTC, PBT, SCFR}, Nkx2-2 (NK2 homeobox 2) [NCBI Gene 18088] {aka Nkx-2.2, Nkx2.2, tinman}, CLDN1 (claudin 1) [NCBI Gene 9076] {aka CLD1, ILVASC, SEMP1}, NCAM1 (neural cell adhesion molecule 1) [NCBI Gene 4684] {aka CD56, MSK39, NCAM}, PAX7 (paired box 7) [NCBI Gene 5081] {aka CMYO19, CMYP19, HUP1, MYOSCO, PAX7B, RMS2}, MYOG (myogenin) [NCBI Gene 4656] {aka MYF4, bHLHc3, myf-4}, Trp63 (transformation related protein 63) [NCBI Gene 22061] {aka Ket, P51/P63, P63, P73l, Tp63, Trp53rp1}, Ccnd1 (cyclin D1) [NCBI Gene 12443] {aka CycD1, Cyl-1, PRAD1, bcl-1, cD1}, Bcl2 (B cell leukemia/lymphoma 2) [NCBI Gene 12043] {aka Bcl-2, C430015F12Rik, D630044D05Rik, D830018M01Rik}, Bcl6 (B cell leukemia/lymphoma 6) [NCBI Gene 12053] {aka Bcl5}, VIM (vimentin) [NCBI Gene 7431], Cd99 (CD99 antigen) [NCBI Gene 673094] {aka 1110061M03Rik, 2410026K10Rik, D4, Pilr-l, pilr-1}, MYOD1 (myogenic differentiation 1) [NCBI Gene 4654] {aka CMYO17, CMYP17, MYF3, MYOD, MYODRIF, PUM}, Mki67 (antigen identified by monoclonal antibody Ki 67) [NCBI Gene 17345] {aka D630048A14Rik, Ki-67, Ki67}, CD99 (CD99 molecule (Xg blood group)) [NCBI Gene 4267] {aka HBA71, MIC2, MIC2X, MIC2Y, MSK5X}, BCL2 (BCL2 apoptosis regulator) [NCBI Gene 596] {aka Bcl-2, PPP1R50}, S100A1 (S100 calcium binding protein A1) [NCBI Gene 6271] {aka S100, S100-alpha, S100A}, Satb2 (special AT-rich sequence binding protein 2) [NCBI Gene 212712] {aka BAP002, mKIAA1034}, Syp (synaptophysin) [NCBI Gene 20977] {aka A230093K24Rik, Syn, p38}, Wt1 (WT1 transcription factor) [NCBI Gene 22431] {aka D630046I19Rik, Wt-1} - **Diseases:** nasal blockage (MESH:D015508), neuroblastoma (MESH:D009447), Necrosis (MESH:D009336), neuroendocrine tumors (MESH:D018358), sarcomas (MESH:D012509), undifferentiated small round cell sarcomas (MESH:D018228), proptosis (MESH:D005094), acute leukemia (MESH:D015470), diffuse endothelioma of bone (MESH:D006390), mesenchymal chondrosarcoma (MESH:D018211), sinonasal mass (MESH:C536030), hemorrhage (MESH:D006470), rhabdomyosarcoma (MESH:D012208), embryonal rhabdomyosarcoma (MESH:D018233), lymphoma (MESH:D008223), PNET (MESH:D018242), olfactory neuroblastoma (MESH:D018304), epistaxis (MESH:D004844), ossifying fibroma (MESH:D018214), extranodal NK/T cell lymphoma (MESH:D054391), Ethmoidal sinus tumors (MESH:D009369), calcification (MESH:D002114), round (MESH:D018208), undifferentiated carcinoma (MESH:D002277), EES (MESH:D012512), soft tissue tumors (MESH:D012983), facial swelling (MESH:D004487), Head and Neck Tumors (MESH:D006258), sinonasal (MESH:C535701), NCMH (MESH:D006222), small-cell carcinoma (MESH:D018288), sinonasal melanoma (MESH:D008545), osteosarcoma (MESH:D012516), round cell tumors (MESH:D058405), synovial sarcoma (MESH:D013584), bone malignancies (MESH:D001859) - **Chemicals:** cyclophosphamide (MESH:D003520), ifosfamide (MESH:D007069), glycogen (MESH:D006003), Vincristine (MESH:D014750), etoposide (MESH:D005047), VDC-IE (-), doxorubicin (MESH:D004317) - **Species:** Homo sapiens (human, species) [taxon 9606] ## Figures 3 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12966617/full.md --- Source: https://tomesphere.com/paper/PMC12966617