EWSR1-CREB1 fusion

High-throughput sequencing identified EWSR1::CREM fusion in case 1, whereas fluorescence in situ hybridization detected EWSR1::CREB1 fusion in case 2. These cases expand the morphological and immunophenotypic characteristics of malignant epithelioid tumors with EWSR1::CREB fusion, highlighting the diagnostic challenges of immunohistochemistry and value of molecular testing for accurate diagnosis.

Its clinical manifestation is unspecific and only molecular genetic method can proof this diagnosis. This paper describes an unusual clinical presentation of primary pulmonary myxoid sarcoma in a 68-year-old patient with involvement of both lungs.

For instance, clinical trials are available for patients with NUT carcinoma, SMARCA4-DUT, and SMACRB1-deficient neoplasms. Herein, our current knowledge of clinical, morphologic, immunophenotypic, and molecular features of NUT carcinomas, SMARCA4-DUT, primary pulmonary myxoid sarcomas, hyalinizing clear cell carcinoma, and SMARCB1-deficient neoplasms will be reviewed.

EWSR1 rearrangement and EWSR1::CREB1 fusion are crucial genetic features of PPMS and serve as important diagnostic markers. Immunohistochemically, PPMS tests positive for EMA. In terms of treatment, surgery has been the primary approach in recent years. Therefore, the efficacy of other treatments still requires further investigation.

While rare, the differential should also include IMT. Biopsy or resection with histologic, immunohistochemical, and molecular characterization is necessary for definitive diagnosis.

The patient lives with recurrent lesions for 8 months. This case was associated with several unusual features and contributes to the evolving GNET concept.

Pathological findings and gene rearrangements are important for the diagnosis of primary pulmonary myxoid sarcoma. Complete resection and careful observation are required.

The striking pseudopapillary architecture and the intracranial location of case 2 rendered differential diagnoses including meningioma and ependymoma. With the peculiar locations and morphology, these cases posed great diagnostic challenge.

Together, these findings confirm that intracranial AFH-like neoplasms and IMMT represent histologic variants of a single tumor type ('intracranial mesenchymal tumor, FET-CREB fusion-positive') that is distinct from meningioma and extracranial sarcomas. Additionally, epigenomic evaluation may provide important prognostic subtyping for this unique tumor entity.

Here, we describe a case of clear cell sarcoma-like tumour of jejunum encountered by us in a young man. The immunohistochemical and genetic profiling of these tumours are also discussed.