A unique case of adamantinoma-like Ewing sarcoma in the calcaneus, exhibiting prominent squamous differentiation and displaying EWSR1 gene rearrangement

Rekhi, Bharat; Kothari, Rushabh; Shah, Sudeep R.; Shetty, Omshree; Shah, Mandip C

doi:10.1007/s00256-021-03831-7

Cited by 4 publications

(3 citation statements)

References 22 publications

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“…ALES is a rare subtype of Ewing sarcoma with 56 cases 1–3,6,8,9,14–41 reported to date, including the ones reported in this study and 1 case of Ewing sarcoma with strong nuclear expression of p40 and FUS :: FEV fusion described by Tsuda et al 37 Although they mention the possibility of ALES, Tsuda and colleagues do not clearly separate it out as a unique finding in their cohort of Ewing sarcomas with FEV gene rearrangements. Nevertheless, when included as ALES, the proportion of ALES with FUS rearrangement is around 13% (7/56) of reported cases which is slightly higher than the proportion of FUS rearrangement reported in classic Ewing sarcoma (<10%) 10,13 .…”

Section: Discussionmentioning

confidence: 51%

Adamantinoma-like Ewing Sarcoma (ALES) May Harbor FUS Rearrangements

Nguyen

Foss²,

et al. 2023

American Journal of Surgical Pathology

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Adamantinoma-like Ewing sarcoma (ALES) is a rare malignancy currently considered a variant of Ewing sarcoma with most known cases harboring EWSR1 rearrangements. Herein we present a series of 6 cases of EWSR1-negative ALES. The tumors arose in the sinonasal tract (n=3), major salivary glands (submandibular gland=1; parotid=1), and anterior mediastinum (n=1) in patients ranging from 25 to 79 years of age. Most tumors were basaloid in appearance, growing in large nests separated by interlobular fibrosis without overt squamous pearls. However, 1 case closely resembled a well-differentiated neuroendocrine tumor with uniformly round nuclei, eosinophilic cytoplasm, and trabecular architecture. All cases were diffusely positive for pan-cytokeratin, p40 or p63, and CD99. A subset of cases showed diffuse reactivity for synaptophysin, including 1 sinonasal tumor which also demonstrated sustentacular S100 protein expression. Molecular testing showed FUS rearrangements in all cases. Gene partners included known ETS family members FEV (n=2) and FLI1 (n=1). Our results expand the molecular diagnostic considerations for ALES to include FUS rearrangements. We also show that ALES may harbor FUS::FLI1 fusion, which has not been previously reported in the Ewing family of tumors. Furthermore, ALES may show unusual histologic and immunophenotypic features that can overlap with olfactory carcinoma including S100-positive sustentacular cells. ALES should be considered in the diagnostic differential of small round cell tumors and tumors with neuroendocrine differentiation with immunohistochemical workup to include p40 and CD99/NKX2.2.

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Section: Discussionmentioning

confidence: 51%

Adamantinoma-like Ewing Sarcoma (ALES) May Harbor FUS Rearrangements

Nguyen

Foss²,

et al. 2023

American Journal of Surgical Pathology

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“…While lack of any other lesion elsewhere in the body, clinical examination, and radiological imaging, ruled out a metastatic sarcomatoid carcinoma in those two tumors, the presence of spindle-shaped nuclei and lack of NKX2.2 immunostaining (tested in two tumors) made the possibility of Ewing sarcoma, including adamantinoma-like Ewing sarcoma, as less likely. 19,20 Apart from the third case, NKX2.2 was negative in the first case, that seemed to lessen the possibility of Ewing sarcoma, although rarely, Ewing sarcomas lacking NKX2.2 have been reported. [21][22][23] The other differentials on histopathologic examination that might be considered include fibroblastic osteosarcoma, leiomyosarcoma, and rhabdomyosarcoma with a spindle cell component, the latter considered in the fifth case.…”

Section: Adamantinomas Characterized By Predominant Spindle Cells Hav...mentioning

confidence: 90%

“…3,24 Similarly Ewing sarcoma, including adamantinoma-like Ewing sarcoma, which occurs in the extremities is currently treated with a specific neoadjuvant chemotherapy regimen, followed by complete resection. 19,20 A metastatic carcinoma would also be managed with adjuvant therapies and would be associated with a relatively poor prognosis. 25,26 All six patients were treated with surgical resection in the present study.…”

Section: Adamantinomas Characterized By Predominant Spindle Cells Hav...mentioning

confidence: 99%

Adamantinoma with a Prominent Spindle Cell Component Mimicking Intraosseous Synovial Sarcoma: Clinicopathological Features of Six Tumors

et al. 2022

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Introduction. Adamantinoma is sub-classified into classic/biphasic, osteofibrous dysplasia-like, and de-differentiated type. We present six adamantinomas with a prominent spindle cell component mimicking intraosseous synovial sarcomas. Methods. Six patients were either referred with a diagnosis of intraosseous synovial sarcoma or wherein synovial sarcoma was a differential diagnosis. Three tumors were tested for SS18 gene rearrangement by FISH and two for SS18::SSX fusion by RT-PCR technique. Results. There were three males and three females with an average age of 20.6 years. Radiologically, the lesions were expansile and showed lytic and/or sclerotic components, involving the cortex and/or medulla. Five lesions occurred in the tibia and two in the fibula. Two tumors displayed soft tissue extension and two occurred as multifocal lesions. Two patients were diagnosed with synovial sarcoma and a single patient with sarcomatoid carcinoma, elsewhere. Two “in-house” patients were initially diagnosed with synovial sarcomas. On review, all tumors were cellular comprising monomorphic spindle-shaped cells arranged in sheets and fascicles (n = 6), including a “herringbone-like” pattern (n = 3), focal tubules (n = 1), cohesive nests (n = 5), cords (n = 2), including pseudocystic component (n = 2). Immunohistochemically, tumor cells were positive for p63 (6/6), p40 (4/4), EMA (2/3), AE1/AE3 (5/6), various keratins (2/2), and TLE1 (2/4). Three tumors tested for SS18 rearrangement were negative, while two tumors tested for SS18::SSX fusion were negative. Conclusions. Adamantinomas with spindle cell morphology display overlapping features with synovial sarcoma. A clinico-radiological index of suspicion immunostains (p63 and p40) and molecular test for t(X; 18) translocation are useful in an exact diagnosis, which has treatment-related implications.

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