RB1 deletion

Survivors of hereditary retinoblastoma, caused by germline mutations in the RB1 gene, have a substantially increased risk of developing benign and malignant lipomatous tumors including atypical spindle cell/pleomorphic lipomatous tumor and dysplastic lipoma. This report describes the MRI findings of several such lesions in a survivor of bilateral retinoblastoma including features such as enhancement that might otherwise be concerning for higher-grade malignancy.

Most patients followed an aggressive clinical course, including metastases and disease-related mortality. These findings expand the spectrum of sarcomas driven by FGFR gene fusions, underscoring the importance of molecular testing for accurate diagnosis and potential targeted therapy in high-grade sarcomas with myogenic features.

Our review did not uncover features to improve grading of oligodendroglioma, IDH-mutant and 1p/19q-codeleted, although CNS WHO grade 3 tumors with elevated mitotic rates, yet lacking necrosis, microvascular proliferation, CDKN2A/B homozygous deletion and MRI contrast enhancement, may be associated with extended survival. Implementing evidence-based criteria for risk stratification and grading will improve guidance for clinical decision-making.

Differentially methylated region analysis suggested that resistance to regorafenib may involve disruptions in WNT signaling, cadherin-mediated adhesion, and presenilin pathways. These findings highlight the potential of DNA methylation profiling in guiding therapeutic strategies and warrant further validation in clinical settings.

This case highlights the diagnostic challenge posed by the coexistence of marked eosinophilia and NSMM, which obscured the underlying plasma-cell malignancy despite repeatedly negative monoclonal protein studies. We also reviewed the limited literature on MM-associated eosinophilia to underscore the importance of integrating bone marrow findings, imaging, and cytogenetic evaluation in atypical cases.

This study provides an overview of the spectrum of germline cytogenetic alterations and clinical features in Mexican patients with RB. Our results expand the understanding of RB in this population and underscore the need for multimodal approaches for the detection and functional characterization of RB1 alterations. This study reports the largest Mexican retinoblastoma cohort with comprehensive germline RB1 characterization and high detection rates, particularly in bilateral disease.

Flow cytometric immunophenotyping demonstrated bright CD45 expression with low side scatter and positivity for CD19, CD20, CD38, CD5, CD79b, and FMC7 with negativity for CD34, CD23, CD200, and CD10, suggesting blastoid transformation of MCL rather than de novo ALL. This case highlights the critical role of flow cytometry in distinguishing blastoid MCL from acute leukemia, thereby preventing misdiagnosis and ensuring appropriate therapeutic decision-making.

Among patients receiving bortezomib, lenalidomide, and dexamethasone (VRd) induction therapy, those with cytogenetic abnormalities showed significantly lower deep response rates (complete response + very good partial response). Furthermore, RB1 deletion or D13S319 deletion combined with other high-risk indicators further shortened PFS. These findings indicate that integrating expanded cytogenetic markers optimises MM risk stratification and provides a basis for individualised treatment strategies.

Conversely, in prostate adenocarcinoma models, DNMT1 deletion leads to de-repression of neuroendocrine lineage genes with a loss of H3K27me3 marks. Our findings reveal a functional interplay between two repressive epigenetic machineries that mediates lineage plasticity in prostate cancer.

The B-ALL patients with concurrent RB1 and IKZF1 deletions had worse outcomes compared to cases without any of these deletions. The RB1 deletion increased the risk of early events in patients with the IKZF1plus profile.

This is similar to well-differentiated NETs of other organs, in particular the small intestine and lung. Overall, our findings support the grouped classification of MeNET within the larger NET scheme.