Rhabdomyosarcoma

Here, we describe two patients with EWSR1::PATZ1 sarcoma, of which one patient was initially misdiagnosed as synovial sarcoma and RMS on two occasions. These patients underscore the diagnostic challenges and therapeutic uncertainties surrounding EWSR1::PATZ1 fusion sarcomas, emphasizing the need for further large collaborative studies to establish optimal prognostic implications and management strategies for this rare entity.

P2/3, N=140, Completed, National Cancer Institute (NCI) | Active, not recruiting --> Completed | Trial completion date: Dec 2026 --> Mar 2026

A complete blood count obtained locally after return home showed severe cytopenias, prompting growth-factor support and close hematology-oncology follow-up. This case highlights that PPB should be prioritized in the differential diagnosis of aggressive pediatric intrathoracic masses with pneumothorax and mass effect, and demonstrates the value of adequate tissue sampling, expert pathology review, and early integration of molecular testing to prevent protocol misdirection and to trigger DICER1-directed genetic counseling and surveillance.

Histologic subtyping of unclassified sarcomas predicted prognosis and therapeutic response. We propose universal MMR IHC screening of (1) PRMS, (2) uterine LMS, (3) unclassified/UPS, and (4) any sarcoma in a patient with a personal or family history of Lynch syndrome.

In addition, we demonstrate that the first bromodomain of the bromodomain and extraterminal domain-containing protein BRD4 binds to the acetylated region of interest and that this interaction is inhibited through the bromodomain and extraterminal domain inhibitor JQ1. These findings confer molecular mechanistic detail to previous observations that BRD4 and PAX3-FOXO1 colocalize at superenhancers in ARMS, adding to the growing body of literature exploring how BRD4 contacts cancer-relevant transcription factors in ways potentially relevant to the use of bromodomain and extraterminal domain inhibitors in cancer treatment.

In conclusion, PATZ1 IHC is moderately sensitive and specific for PATZ1-rearranged sarcomas, and it may be a helpful diagnostic marker for this challenging tumor. While most tumors with morphologic overlap with PATZ1-rearranged sarcomas are negative for PATZ1 by IHC, expression in a subset of myoepithelial tumors and rhabdomyosarcomas represents a potential diagnostic pitfall.

PRAME is an antigen that has been described in primary cutaneous and metastatic melanomas and has become a useful ancillary immunohistochemical marker, particularly when all others are negative. We present a patient with metastatic melanoma to the left atrium with loss of melanocytic differentiation, gain of a rhabdomyosarcomatous differentiation, and a diffuse and strong positivity for PRAME.

This phenomenon was evidenced by the following indicators: reduced clone formation, increased cell apoptosis, cell cycle arrest, as well as the inhibition of tumor cell proliferation. Taken together, our study revealed that shepherdin not only modulates the biological behavior of RMS cells but also enhances their sensitivity to X-ray irradiation, demonstrating its potential as an effective therapeutic strategy for RMS.

This updated review synthesizes current knowledge of DICER1 biology, the historical evolution of the syndrome, the distinctive clinicopathologic features of associated tumors, provides a practical diagnostic algorithm to guide pathologists in recognizing sentinel lesions and initiating germline testing, and recent advances in the study of this syndrome and the DICER1 gene. By integrating molecular mechanisms with evolving clinical practice, this article aims to equip diagnostic pathologists and multidisciplinary teams with diagnostic tools and correlations for the detection and management of DICER1 syndrome.

CART-Vac effectively mediated transient expression, significantly enhancing CAR T expansion and antitumor activity in both models. These findings suggest that CART-Vac can modulate the TME, offering a promising strategy to improve the therapeutic efficacy of CAR T cells in solid tumors.

In conclusion, our multi-omics analysis identifies HMGA2 fusion as a promising diagnostic and prognostic biomarker for DDLPS with rhabdomyosarcomatous differentiation. The comprehensive molecular and immune landscape of this tumor subtype not only deepens our understanding of its pathophysiology but also provides critical insights for future precision medicine strategies.

P1, N=25, Recruiting, University of California, Irvine