Extra-osseous Ewing sarcoma of the thyroid gland mimicking lymphoma recurrence: A case report

Extraosseous Ewing's Sarcoma Masquerading as Adolescent Neck Mass-a Case Report and Review of Literature

Ewing sarcoma (ES) is a rare type of malignant bone tumor that arises from mesenchymal stem cells. It commonly occurs in the diaphysis and diaphyseal-metaphyseal portions of long bones, pelvis, and ribs, although any bone can be affected. A minority of the Ewing sarcoma also arise in soft tissues, and a primary tumor in the neck with metastasis is extremely uncommon. We are reporting the case of a 12-year-old female with a history of fever for 4 months and a neck mass for 3 months. Given the broad range of inflammatory and neoplastic etiologies, an extensive laboratory and imaging workup was conducted. Cervical lymph node biopsy for histopathology showed sheets of round blue cells consistent with the diagnosis of Ewing sarcoma in the neck, while a positive immunohistochemical assays for NKX2.2, and negative assay for PAX-5, TdT markers neurofilament, neuron-specific enolase, and S100 protein ruled out the alternative etiologies such as rhabdomyosarcoma and lymphoma. After surgical excision of tumor, chemoradiotherapy was initiated. Despite the typically benign nature of extraosseous Ewing tumors, they can rarely metastasize in less than 20% of cases, as exemplified by this rare case. Accurate diagnosis requires a combined clinic-radio-immunohistochemical approach, and general practitioners should be aware of this clinical entity in neck masses considering its variable clinical presentation and poor prognosis in certain patient's population.

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

Extra-skeletal Ewing sarcoma (EES) is a rare sarcoma composed primarily of small round cells, capable of metastasizing and relapsing. Few cases of EES originating from the larynx have been reported, and no publications regarding laryngeal EES treated with dendritic cells-cytotoxic T lymphocytes (DC-CTL) immunotherapy have been found. We described a 29-year-old woman with a mass found in the larynx. Diffuse small round cells with scanty cytoplasm shown by histology test and extremely positive staining of CD99 revealed by immunohistochemistry helped determine the diagnosis of laryngeal EES. The patient survived for seven years with no signs of recurrence or metastasis after six cycles of DC-CTL immunotherapy based on traditional treatments. This case indicates that DC-CTL immunotherapy could be considered a new option for treating EES.

Outcome for Neoadjuvant Treatment of Parotid Gland Adamantinoma-Like Ewing Sarcoma: Case Report and Review of Literatures

Background. Adamantinoma-like Ewing sarcoma typically shows t(11;22) EWSR1::FLI1 translocation and complex epithelial differentiation. It poses a diagnostic challenge, especially in the head and neck region, due to its under-recognition and significant histologic overlap with other malignancies. Neoadjuvant and adjuvant treatment information on head and neck Adamantinoma-like Ewing sarcoma is limited. Case Presentation. Herein, we report a case of a 78-year-old female with Adamantinoma-like Ewing sarcoma of the parotid gland, including the imaging findings and clinical response to neoadjuvant therapy followed by surgery. The efficacy of neoadjuvant therapy in the treatment of Adamantinoma-like Ewing sarcoma is discussed in the context of a review of pertinent literature. Conclusion. Adamantinoma-like Ewing sarcoma in the head and neck is frequently misdiagnosed as poorly differentiated squamous cell carcinoma or a basaloid salivary gland carcinoma. Adamantinoma-like Ewing sarcoma is a EWS1::FLI1 translocation driven tumor; frequently misdiagnosed on head and neck biopsies as poorly differentiated carcinoma, or squamous cell carcinoma. Ewing sarcoma-specific chemoregimen appears effective for this entity. If diagnosed early, patient may be amenable to neoadjuvant therapy, which may improve surgical and cosmetic outcomes. This is especially important in head and neck regions.

Small-Cell Malignancies of Thyroid: Challenge Solved?

"Small-cell malignancies of thyroid" is an unsolved dilemma. This term represents an umbrella terminology in thyroid, encompassing for a small group of tumors in which some of them are well-recognized tumors like medullary thyroid carcinoma, poorly differentiated thyroid carcinoma, and primary thyroid lymphomas and teratoma, whereas the remaining are less known as primary neuroendocrine carcinoma of thyroid, primary extraskeletal Ewing family tumors, and adamantinoma-like Ewing sarcoma. When the issue comes to evaluate a cytological sample predominantly composed of small-cell morphology, metastatic small-cell carcinomas to thyroid also should be excluded. In this review, our group focused on the main cytomorphological and clinical clues of each entity that help to set up a correct differential diagnosis. The literature discussions were also included for the entities that are not yet recognized by the mother publication WHO. A key point of the issue's simple algorithm based on FNAC with small-cell morphology of thyroid was suggested by the authors.

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

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.

Ultrastructure of CIC-DUX4 sarcoma: the first pathological report

CIC-DUX4 sarcoma (CDS) is a recently identified subtype of small round cell sarcoma. Morphologically, CDS partially resembles Ewing sarcoma (ES) and has been classified as "ES-like sarcoma"; however, detailed clinicopathologic and molecular genetic analyses have indicated that CDS is a new independent disease. Many studies have provided light microscopic, immunohistochemical, and genetic information about CDS. However, ultrastructural findings associated with this sarcoma are lacking. The aim of this study was to investigate the ultrastructure of CDS tumors and to compare their features with those of ES. We examined two cytogenetically confirmed CDS cases. We found that, compared to typical ES, CDS presented heterogeneity: in cell density, from tightly packed to loosely unconnected areas; in cell shape, from polygonal to pleomorphic with small processes; and in nuclear shape including round, oval, polygonal, elongated, invaginated, or wrinkled formations. However, abundant glycogen in the cytoplasm and rare cell adhesion apparatus between cells are major similarities between CDS and typical ES. Neuroendocrine granules, which are seen in rare ES cases, could not be identified in these two CDS cases. Although cytogenetic differences can validate a definite diagnosis, ultrastructural features could also provide important information about the differences between CDS and ES.

Fifty years of thyroid pathology: concepts and developments

The past half century has seen a number of advances in pathology of thyroid diseases, especially neoplastic lesions. These include the description of new entities, the definition of prognostically important lesions, the incorporation of fine needle aspiration biopsy and its functional risk stratification of diagnoses into the clinical evaluation and therapeutic recommendations of the patient with thyroid nodules and the understanding of thyroid neoplastic development, diagnostic and prognostic parameters by use of molecular analysis so that such techniques are becoming standard of care for patients with thyroid tumors. The histopathologist and cytopathologist have been and continue to be at the forefront in the definition and understanding of these areas of thyroid disease. This review describes many of the most important advances in this area in an attempt bring the practicing pathologist up to date in these developments.

Metastasis of Ewing's sarcoma to the thyroid gland: A case report

Ewing's sarcoma (ES) is an aggressive pediatric malignancy. We present a case of ES with thyroid metastasis. The patient was diagnosed with ES at age 8. Despite aggressive treatment, she suffered disease progression. Surveillance demonstrated a left thyroid lesion. This grew rapidly within 2 months, causing tracheal compression. She underwent hemi-thyroidectomy to prevent airway compromise. Due to her refractory ES, she was enrolled in the Vigil immunotherapy vaccine trial; thus, the specimen was used for vaccine development. This is the first reported case of skeletal ES with metastasis to the thyroid, requiring hemithyroidectomy to prevent airway compromise.

EWSR1 rearrangement is a frequent event in papillary thyroid carcinoma and in carcinoma of the thyroid with Ewing family tumor elements (CEFTE)

Carcinomas of the thyroid with Ewing family tumor element (CEFTEs) are small-cell thyroid tumors with epithelial differentiation that disclose p63 expression and EWSR1-FLI1 rearrangement, carry a favorable prognosis and may co-exist with papillary thyroid carcinoma (PTC) foci. Two histogenetic hypotheses have been advanced regarding the origin of CEFTEs: arising in PTCs or in solid cell nests (SCN). A total of 3 CEFTEs, 54 PTCs, and 10 SCNs were reviewed, and fluorescence in situ hybridization (FISH) technique was performed in all cases to search for the presence of EWSR1 rearrangements. The three CEFTEs disclosed the EWSR1-FLI1 rearrangement both in the small cell and in the PTC component. Out of the 54 PTC cases, 28 (51.9%) were positive, 20 (37.0%) were negative, and 6 (11.1%) were inconclusive for EWSR1 rearrangement; in two of the positive PTC cases, the EWSR1-FLI1 rearrangement was detected. Classic PTC disclosed more often the EWSR1 rearrangement than other PTC variants (p = 0.031). PTCs with EWSR1 rearrangement disclosed a lower percentage of nuclei with EWSR1 polysomy than those without EWSR1 rearrangement (p = 0.001). Out of the 10 SCNs, 7 (70.0%) were negative and 3 (30.0%) were inconclusive for the EWSR1 rearrangement. Monosomic nuclei were more frequent (mean of 44.3%) in SCNs than in PTCs (p < 0.001). The presence of the EWSR1-FLI1 rearrangement in PTC component of all studied CEFTEs and the existence of the EWSR1 rearrangement in some PTCs favor the origin of CEFTE from PTC. The high frequency of EWSR1 rearrangements in PTC may represent a new diagnostic marker of these tumors.

Primary Ewing Sarcoma of the Thyroid-Eight Cases in a Decade: A Case Report and Literature Review

Sarcomas represent less than 1% of all malignant tumors found in the thyroid. Of these, primary extraosseoussarcoma has been reported only a few times in the past decade. We present the case of a 34-year-old male who had a fast-growing hard mass in the lower left neck. FNA was inconclusive. Core needle biopsy revealed the diagnosis of an Ewing sarcoma/primitive neuroectodermal tumor. Mutation of EWSR1 was confirmed using the FISH method. Following treatment by neoadjuvant chemotherapy, we observed clinical, radiological, and finally histopathological remission. This was followed by a left-sided isthmolobectomy with unilateral cervical lymph node dissection by lateral lymphadenectomy, which revealed no residual disease. Posttreatment radiotherapy was administered but discontinued upon the patient's request. After 18 months of observation, the patient had no recurrence or metastasis and required l-thyroxine supplementation. We discuss our case using a comparative literature review to the few other known case reports.

Extraosseous Ewing sarcoma and peripheral primitive neuroectodermal tumor of the thyroid gland: Case report and review

The Ewing family of tumors and peripheral primitive neuroectodermal tumor (pPNET) represent different manifestations of the same entity. Immunohistochemical and cytogenetic studies suggest that these tumors have a common origin. Ewing sarcoma is more common in bone, while pPNET is more common in soft tissues. Extraosseous Ewing sarcoma (EoES) is rare. We present the case of a 48-year-old man who presented with acute obstructive respiratory failure secondary to a large thyroid swelling. The patient was initially diagnosed with giant B-cell non-Hodgkin lymphoma and treated with chemotherapy. However, subsequent immunohistochemical staining of biopsy specimens revealed that the patient actually had EoES/pPNET of the thyroid gland. We performed a nearly complete surgical resection of the tumor plus a total laryngectomy and resection of five tracheal rings. However, the patient died of a cerebral metastasis 1 month later after he had completed one cycle of postoperative chemotherapy.

Small cell tumors of the thyroid gland: a review

The small cell group of thyroid tumors that includes lymphoma, poorly differentiated carcinoma, medullary carcinoma, secondary neoplasms, as well as tumors with uncertain histogenesis, remains as a valid diagnostic cul-de-sac due to its heterogeneous constitution. The existence of small cell thyroid tumors with EWSR1-FLI1 rearrangement together with neuroendocrine and/or carcinomatous differentiation raises not only differential diagnostic problems but also a very interesting therapeutic dilemma. This review explores the classification of small cell tumors of the thyroid taking into account the immunophenotype and molecular profile of such tumors.

Carcinoma of the thyroid with ewing family tumor elements and favorable prognosis: report of a second case

The rare reports of primary, nonneuroendocrine small cell carcinomas of the thyroid have not provided enough evidence to support the recognition of these tumors as an entity or to understand their etiopathogenesis. We report the second case of a primary, nonneuroendocrine small cell carcinoma of the thyroid displaying diffuse expression of cytokeratins, CD99, and p63, in the absence of vimentin expression, in a 24-year-old male who is alive without any signs of disease 13 years after total thyroidectomy and radioactive iodine. The tumor disclosed the EWSR1-FLI1 rearrangement, and we propose to designate it as a carcinoma of the thyroid with Ewing family tumor elements.