Primary Ewing sarcoma of the squamous temporal bone with intracranial and extracranial extension: A rare cause of sudden sensorineural hearing loss

Abstract

Background Primary Ewing sarcoma of the cranial bone is rare, accounting for only 1% of all Ewing sarcomas. Primary Ewing sarcoma arising in the squamous temporal bone is particularly rare. Methods A 16‐year‐old male was seen with signs of sudden sensorineural hearing loss (SSNHL). After 1 week of SSNHL and new‐onset headache, imaging studies showed a mass that originated in the left squamous temporal bone with intracranial and extracranial extension. Histopathological study revealed that the mass was a Ewing sarcoma. Results The patient manifested the diagnostic EWSR1 mutation and was treated with adjuvant multidrug chemotherapy and focal radiotherapy after surgery according to the Children's Oncology Group interval compression arm of AEWS0031 with a regimen of vincristine, doxorubicin, and cyclophosphamide alternating with ifosfamide/etoposide. Conclusions This case showed an extremely uncommon location, as well as unusual symptoms of primary Ewing sarcoma.

Primary Intracranial Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor Mimicking Meningioma: A Case Report and Literature Review

“…Moreover, the tumor cells are markedly fibrotic, highly mitotic, and separated by groups of cells containing collagen bands ( 1 , 3 , 4 , 14 , 18 ). Membranous expression of CD99 is a highly reliable and sensitive diagnostic biomarker for primary intracranial ES/pPNETs ( 3 , 4 , 13 – 15 , 18 ), and was detected in nearly all patients. However, CD99 is not recommended as a specific immunohistochemical marker for diagnosing ES/pPNETs, because CD99 can also be detected in other small, blue round cell tumors, including lymphoblastic lymphomas, ependymomas, and rhabdomyosarcomas ( 2 , 4 , 14 , 21 , 23 ).…”

“…Chromosomal translocation t ( 11 , 22 )(q24;q12) is the most common genetic aberration in ES/pPNETs. This translocation results in formation of a chimeric transcription factor EWS-FLI-1 (friend leukemia integration 1 transcription factor) in 85–90% of ES/pPNETs, being the in-frame fusion of the 5' end of EWSR1 gene with the 3' portion of the FLI-1 gene with abnormal transcription regulator properties ( 1 , 4 , 13 – 15 , 18 ). The downstream effects of the EWS-FLI-1 fusion gene include dysregulation of cell proliferation, differentiation, apoptosis, angiogenesis, invasion, and metastasis ( 25 ).…”

“…The pseudoautosomal gene, MIC2 gene, is another important gene, which has been demonstrated to be present in ES/pPNETs ( 17 , 18 ). The cell surface glycoprotein CD99 is the product of the MIC2 gene, which is observed in essentially all cases of ES/pPNETs ( 15 , 17 ).…”

“…To date, surgical resection, with the aim of total tumor resection, is the main therapy cornerstone ( 3 , 4 ). Wide surgical resection margins at the time of primary surgery have markedly reduced local recurrences ( 13 , 15 ). Chen et al found the lifetime of gross total resection (GTR) to be significantly longer when compared to partial resection (38 months vs. 20 months, respectively) ( 4 ).…”

“…For patients over 30 years of age, only 9 cases have been reported ( 4 – 12 ). Fusion of the EWSR1 gene with a member of the ETS gene family is thought to be the primary cause of the ES/pPNETs ( 3 , 4 , 13 – 15 ). Herein, we present a case of ES/pPNET located in the left frontal lobe of a 55-year-old female, who was tested through histological examination, immunohistochemical analysis and fluorescence in situ hybridization (FISH).…”