ALK1 (Activin A Receptor Like Type 1)

Although PCNSTL is exceptionally rare, we identified distinct neuroimaging patterns showing highly aggressive features on MRI but hypometabolic PET imaging, which may assist in identifying future PCNSTL cases. Despite the limited cohort size, our findings suggest that MTX-based chemotherapy with ASCT may translate into favorable outcome. We report on an ALK1-positive PCNSTL case with sustained complete remission after targeted therapy with lorlatinib.

MD from a single-slice ROI is optimal for the identification of p53 abnormality, combining diagnostic performance with operational simplicity and high reproducibility. For MSI prediction, ADC from a whole-tumor ROI is preferred due to its superior sensitivity and excellent reproducibility.

While the classic hepatosplenic and hematopoietic manifestation have been well described, APH manifesting in the head and neck is a distinct phenomenon that has only been reported on rare occasions. We provide a review of the literature of all cases of ALK positive histiocytosis affecting the head and neck to provide an overview of the clinicopathologic features as well as the molecular findings of this rare entity.

Immunohistochemistry for ALK and HHV8 should be included in the diagnostic panel. Importantly, CD30 and EBER positivity do not exclude ALK + LBCL.

Here, we report a lung IMT in a 45-year-old female demonstrating a unique meningothelial-like pattern, equivocal ALK expression (negative for clone 5A4 and positive for clone ALK1), negative ALK rearrangement by FISH, and the presence of the TPM3::ALK fusion. To our knowledge, this is the first reported case of lung IMT displaying meningothelial-like whorls, with a particular focus on differential diagnosis.

It also underscores the critical role of immunohistochemistry, particularly STAT6 staining, in distinguishing SFT from histologic mimics. Vigilant follow-up remains essential, especially in atypical or CD34-negative cases, given their potential for aggressive behavior.

Molecular docking revealed that the core targets were stably bound to the corresponding compounds. This study provides a scientific basis for analyzing the bioactive compounds in Co-DZZY Capsules and their pharmacological mechanisms of action.

Given his age, the patient started on treatment with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone at reduced doses (R-miniCHOP) and had a complete response. To our knowledge, there are no other reported cases of complete remission following an attenuated R-miniCHOP protocol in this clinical scenario.

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.

P1/2, N=121, Recruiting, Precision Biologics, Inc | Trial completion date: Oct 2026 --> Jan 2029 | Trial primary completion date: Oct 2025 --> Jan 2028

P2, N=13, Completed, Unity Health Toronto | Active, not recruiting --> Completed | N=30 --> 13

Solid masses in extracavitary PEL have been shown to involve lymph nodes and/or solid organs such as the gastrointestinal tract, lung, liver, spleen, and skin, with a similar phenotype as classic PEL except that they may express B-cell markers with lower expression of CD45 and/or aberrant coexpression of T-cell antigens. This case illustrates the unusual manifestation of PEL as a mediastinal mass with associated HLH.