The histomorphologic and immunohistochemical features of the histiocytic sarcoma in this Lemur catta were characteristic of this condition in other species. This report documents the first case of histiocytic sarcoma in Lemur catta, providing novel histopathological and immunohistochemical insights of this condition in prosimians.
Their diagnosis requires careful consideration to accurately distinguish rare indolent entities, recently defined large B‑cell lymphomas, and reactive mimics. Recent classifications, including the newly introduced WHO Classification of Pediatric Tumors, increasingly reflect these unique aspects.
This case represents a rare pcTFH-PTCL with a persistent T-cell clone coexisting with divergent clonal B- and plasma cell populations. The findings emphasize the role of TFH-derived neoplasms in fostering B-cell expansions and highlight the diagnostic and therapeutic complexity posed by dual-lineage clonality in cutaneous lymphomas.
5 days ago
Journal • PD(L)-1 Biomarker • IO biomarker
|
DNMT3A (DNA methyltransferase 1) • PD-1 (Programmed cell death 1) • BCL6 (B-cell CLL/lymphoma 6) • IGH (Immunoglobulin Heavy Locus) • CD4 (CD4 Molecule) • ICOS (Inducible T Cell Costimulator)