DUSP22 (Dual Specificity Phosphatase 22)

Our findings unveil a novel phosphorylation-dependent DUSP22-LGALS1 axis that reprograms the immunosuppressive TME. This work thus proposes a promising therapeutic strategy to overcome immune checkpoint blockade resistance in breast cancer.

We introduce an integrated molecular classification that preserves currently diagnosed ALCL entities but identifies four molecularly distinct ALK- ALCL subtypes (DUSP22-rearranged, TP63-rearranged, TN-I, and TN-II). This classification can be easily implemented on paraffin tissue in routine practice or clinical trials and stratifies ALCL into diagnostically, prognostically, biologically, and potentially therapeutically relevant subtypes.

This is a unique presentation of LyP with concurrent DUSP22-IRF4 gene rearrangement and TCR gamma-delta phenotype along with an indolent clinical course. Diagnosing LyP can be particularly challenging due to its histologic similarities with other cutaneous lymphomas, underscoring the importance of distinguishing this relatively benign condition from more aggressive malignancies.

Histological and immunophenotypic features were consistent across skin and lymph node biopsies and supported the diagnosis of primary cutaneous origin and were managed with brentuximab vedotin-based chemotherapy, with favorable clinical responses. We emphasize the importance of thorough clinical staging and histopathological correlation to establish the correct diagnosis and the optimal treatment for cases like ours.

In patients with suspected BIA-ALCL, it is critical to properly handle the periprosthetic fluid when the disease first presents and the capsule at the time of initial capsulectomy to make a correct diagnosis and pathologic staging because a missed diagnosis may lead to disease progression. Comprehensive immunohistochemical analysis; fluorescence in situ hybridization for DUSP22, TP63, or JAK2 rearrangement; assessment of clonality of the T-cell receptor and immunoglobulin genes; and sequencing for mutations were performed as part of the workup of the submitted cases, particularly on ALK-negative ALCL cases, emphasizing the importance of ancillary testing in establishing the diagnosis.

PI3K-AKT-mTOR pathway alterations due to PIK3R1 mutations (5/28, 17.8%) were also frequent and mutually exclusive with JAK-STAT pathway activation. In summary, most T-cell neoplasms with CD30/CD15 coexpression share clinical, morphologic, immunophenotypic, and molecular features with ALK-negative ALCL but do not segregate as a homogeneous entity as defined by histologic or genetic features.

In conclusion, phosphatase DUSP22 is a novel target for preventing skeletal muscle wasting and BML-260 treatment is therapeutically effective. The DUSP22-JNK-FOXO3a axis could be exploited to treat sarcopenia or related aging disorders.

An IGH::DUX4 fusion previously found by RNA-seq in Case 3 was not confirmed because DUX4, which has multiple pseudogenes, was refractory to OGM and WGS analyses. OGM is a fundamental tool that complements G-banding analysis in identifying complex SVs in leukemia samples, and WGS effectively closes the gaps in OGM mapping.

Most ALK-negative TCR-γδ-positive pcALCL were CD4-/CD8-, followed by CD4+/CD8-. DUSP22 rearrangement occurred in 40% of cases, similar to reports in typical pcALCL. Its prognosis and the role of DUSP22 are yet to be clarified.

Patient T and NK cells show systemic hypo-responsiveness to interferon, which improves with interferon administration and may represent a therapeutic vulnerability. MYD88-mutant tumors show transcriptional heterogeneity, which can be distilled in a molecular classification, including a DUSP22/CD9-positive subtype, and progression signatures which differentiate IgM MGUS from overt WM and can help advance WM research and clinical practice.

To our best knowledge, this is the first pediatric case of LyP type D with exclusive intraoral involvement.