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Case Reports
. 2023 Jun;17(2):571-575.
doi: 10.1007/s12105-023-01527-z. Epub 2023 Jan 16.

A Low-grade Sinonasal Sarcoma Harboring EWSR1::BEND2: Expanding the Differential Diagnosis of Sinonasal Spindle Cell Neoplasms

Doreen N Palsgrove  1 , Varsha Manucha  2 , Jason Y Park  1 , Justin A Bishop  3   4
Affiliations
Case Reports

A Low-grade Sinonasal Sarcoma Harboring EWSR1::BEND2: Expanding the Differential Diagnosis of Sinonasal Spindle Cell Neoplasms

Doreen N Palsgrove et al. Head Neck Pathol. 2023 Jun.

Abstract

Background: Molecular diagnostics has greatly refined sinonasal tumor pathology over the past decade. While much of the attention has focused on carcinomas, it is becoming clear that there are emerging mesenchymal neoplasms which have previously defied classification.

Methods: Here, we present a 33-year-old woman with a multiply recurrent sinonasal spindle cell tumor exhibiting distinctive features, and not easily classifiable into a specific category.

Results: The hypercellular tumor was composed of plump spindled cells, with uniform vesicular chromatin arranged as vague fascicles around a prominent hemangiopericytoma-like vasculature. The mitotic rate was brisk at 10 per 10 high power fields. By immunohistochemistry, it was only positive for EMA (focal) and SATB2 (diffuse, weak). Fusion analysis uncovered EWSR1::BEND2, a fusion which is best known for being seen in astroblastoma, but which has not yet been reported in sarcomas.

Conclusion: This case underscores the utility of fusion analysis when confronted with a sinonasal spindle cell neoplasm which does not neatly fit into any specific category. It remains to be seen if EWSR1::BEND2 sinonasal sarcoma represents a distinct entity.

Keywords: EWSR1:BEND2; Molecular diagnostics; Sarcoma; Sinonasal tract.

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Conflict of interest statement

All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or non-financial interest in the subject matter or materials discussed in this manuscript.

Figures

Fig. 1
Fig. 1
A The tumor grew as an expansive mass in the sinonasal submucosa beneath a partially ulcerated surface epithelium. B Dilated, hemangiopericytoma-like vessels were conspicuous. C While some areas were more modestly cellular with myxohyaline stroma, D most of the tumor was hypercellular, growing as vague fascicles
Fig. 2
Fig. 2
The tumor cells were epithelioid to spindled, with ample eosinophilic cytoplasm and mostly uniform oval, hypochromatic nuclei. Scattered lymphocytes were seen, and the mitotic rate was brisk at 10 per 10 high power fields
Fig. 3
Fig. 3
Most immunohistochemical assays were negative, with the exception of A SATB2 which was diffuse but weak, and B EMA which was focal
See this image and copyright information in PMC

References

    1. Thompson LDR, Bishop JA. Update from the 5th Edition of the World Health Organization classification of head and neck tumors: nasal cavity, paranasal sinuses and skull base. Head Neck Pathol. 2022;16(1):1–18. doi: 10.1007/s12105-021-01406-5. - DOI - PMC - PubMed
    1. Lewis JT, Oliveira AM, Nascimento AG, Schembri-Wismayer D, Moore EA, Olsen KD, et al. Low-grade sinonasal sarcoma with neural and myogenic features: a clinicopathologic analysis of 28 cases. Am J Surg Pathol. 2012;36(4):517–525. doi: 10.1097/PAS.0b013e3182426886. - DOI - PubMed
    1. Le Loarer F, Laffont S, Lesluyes T, Tirode F, Antonescu C, Baglin AC, et al. Clinicopathologic and molecular features of a series of 41 biphenotypic sinonasal sarcomas expanding their molecular spectrum. Am J Surg Pathol. 2019;43(6):747–754. doi: 10.1097/PAS.0000000000001238. - DOI - PMC - PubMed
    1. Stevens TM, Rooper LM, Bacchi CE, Fernandes IL, Antonescu CR, Gagan J, et al. Teratocarcinosarcoma-like and adamantinoma-like head and neck neoplasms harboring NAB2::STAT6: unusual variants of solitary fibrous tumor or novel tumor entities? Head Neck Pathol. 2022;16(3):746–754. doi: 10.1007/s12105-022-01444-7. - DOI - PMC - PubMed
    1. Mechtersheimer G, Andrulis M, Delank KW, Volckmar AL, Zhang L, von Winterfeld M, et al. RREB1-MKL2 fusion in a spindle cell sinonasal sarcoma: biphenotypic sinonasal sarcoma or ectomesenchymal chondromyxoid tumor in an unusual site? Genes Chromosom Cancer. 2021;60(8):565–570. doi: 10.1002/gcc.22948. - DOI - PMC - PubMed

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