Parotid Ewing's sarcoma: Extra-skeletal uncommon condition

Ewing's sarcoma of the parotid gland: A rare entity with review of the literature

Background

Ewing's sarcoma is a rare malignant entity. Extraosseous Ewing's sarcoma (EES) of the head and neck region is a rare occurrence, and Ewing's sarcoma of the parotid gland is even rarer. To the best of our knowledge, we reported the first case of extraskeletal ES originating from the parotid gland in the Tunisian literature.

Case report

We report a rare case of EES of the parotid gland in a 35-year-old female. She presented with left parotid tumefaction. Physical examination revealed solid and fixed mass associated with facial paralysis. Magnetic resonance imaging illustrated a left intra-parotid process occupying the entire gland measuring 42 mm infiltrating the masseter and pterygoid muscles. The patient had a total left parotidectomy with ipsilateral triangular lymph node dissection. The definitive pathological examination and the immunohistochemical staining confirmed a primary peripheral neuroectodermal tumor or PNET with the presence of a specific EWING/PNET-type translocation in 60% of the tumor cells. She had an adjuvant chemotherapy (four cycles of vincristine, doxorubicin, cyclophosphamide alternating with ifosfamide and etoposide) followed by external radiotherapy.

Conclusion

A clinical and radiological follow-up by cervical MRI was done every 3 months and The 10-month follow-up showed no locoregional and distant recurrence.

Adamantinoma-like Ewing sarcoma of the salivary glands: a case report and systematic literature review

Adamantinoma-like Ewing sarcoma (ALES) of the salivary glands is an exceedingly rare malignancy defined by the t(11,22) EWSR1::FLI1 fusion, with complex epithelial differentiation. To identify features that can allow for better recognition of this disease entity, we reviewed all published reports of molecularly confirmed ALES of the salivary glands and explored epidemiological, clinical, radiological, pathological, and therapeutic characteristics of a population of 21 patients including a single newly reported patient from our group. We searched the English-language literature indexed in PubMed, Medline, Scopus, and Web of Science using the keyword 'Adamantinoma-like Ewing sarcoma' published up to June 2022. The median age at diagnosis was 46 years, and a slight female sex predilection was observed. Most tumors originated in the parotid gland (86%) and presented as a painless palpable mass with a median diameter of 3.6 cm. Metastatic dissemination was reported only in one patient (5%), and after a median follow-up of 13 months the 1-year overall survival rate was 92%. Salivary gland ALES were frequently misdiagnosed at presentation (62% of cases) and were pathologically characterized by the presence of highly monomorphic small round blue cells with infiltrative pattern and positive immunostaining for CD99 and high- and low-molecular weight cytokeratins. Epidemiological and clinical features of salivary gland ALES raise questions on the incorporation of this malignancy in the Ewing sarcoma family tumor group.

Parotid swelling revealing an unusual pathological state: HIV and ewing sarcoma

Swelling of the parotid region is a frequent reason for consultation and the first clinical sign of both benign and malignant parotid tumors.

These parotid tumors represent 80 % of tumors of the main salivary glands. They present a highly variable clinical and radiological picture and are known to have a wide histological diversity. Some histological types are rare entities found in the parotid gland, such as Ewing's sarcoma and lymphoepithelial cyst, the latter of which is often associated with HIV co-morbidity, and therefore requires careful and adequate therapeutic attitudes and strategies.

We report two cases of parotid swelling revealing unusual pathologies: HIV and Ewing's sarcoma.

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Swelling of the parotid region is a frequent reason for consultation.

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Some histological types are rare entities found in the parotid gland.

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The pathological examination of the surgical specimen provides a definitive diagnosis.

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Age can be a concealing element, therefore a careful medical attitude is the key.