Primary Extra-Osseous Ewing Sarcoma of the Thyroid: A Case Report and Review of the Literature

Abstract

Extra-osseous Ewing sarcoma (ES) is a rare and aggressive malignant tumor found in a variety of organs. Primary ES of the thyroid is exceedingly rare and few cases have been documented to date. We describe the case of a 54-year old woman with a history of breast carcinoma in whom a unique hypermetabolic left thyroid nodule was identified during a follow-up PET-CT scan. An ultrasound examination showed a hypoechogenic nodule of 3.7 cm. A cytological diagnosis of poorly differentiated thyroid carcinoma was made, and a total thyroidectomy was performed. The surgical specimen revealed a poorly differentiated neoplasm composed of medium-sized cells with scant cytoplasm, expressing pancytokeratin, CD99 and NKX2.2 but lacking p63 and p40 expression. Molecular analysis revealed a EWSR1-FLI1 fusion transcript supporting the diagnosis of a primary extra-osseous ES of the thyroid. The patient received adjuvant chemotherapy and has no evidence of recurrent disease.

Laryngeal extra-skeletal Ewing sarcoma treated with DC-CTL immunotherapy: A case report and review of the literature

“…Traditionally, surgical excision remains the mainstay of EES treatment, with radiotherapy and chemotherapy used as adjuvant empirical therapies ( 19 ). To gain a better understanding of laryngeal and cervical EES, previous studies were reviewed and listed in Table 1 ( 27 – 53 ). The studies are limited to English language literature published between 1982–2021.…”

Massive swelling of the thyroid in a young patient

“…The thyroid gland is an extremely uncommon location for primary Ewing sarcoma/primitive neuroectodermal tumours (ES/PNET). 1,2 On FNAC, till now only four cases of extraskeletal Ewing sarcoma were reported. Most of the cases were initially diagnosed as non-Hodgkin lymphoma (NHL).…”

“…Carcinoma of the thyroid with Ewing family tumour elements constitutes another set of small blue round cell tumours, and in the literature there is a focus on papillary thyroid carcinoma. 1 An accurate diagnosis of this rare malignancy is crucial, as the treatment modality differs for primary thyroid NET and metastatic disease. 3 Extraskeletal ES is usually an aggressive disease, and local recurrence and distant metastases often occur.…”

“…This entity displays classic ES morphology with epithelial differentiation marked by keratin, p63 or p40 positivity in tumour cells along with identification of EWSR1 rearrangement. Carcinoma of the thyroid with Ewing family tumour elements constitutes another set of small blue round cell tumours, and in the literature there is a focus on papillary thyroid carcinoma 1 . An accurate diagnosis of this rare malignancy is crucial, as the treatment modality differs for primary thyroid NET and metastatic disease 3 .…”

Features of Metastatic Ewing Sarcoma

“…These are expressed in bone, muscle, and soft tissues. Wnt-3a induces morphological changes characterized by the formation of long cytoplasmic extensions in EFT cells (44)(45)(46).…”