GEOapplication/xmlftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE326nnn/GSE326046/primary200OKTranscriptomicsHomo sapiensExpression profiling by high throughput sequencinghttps://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE326046GEOGSEfalseBreast implant associated anaplastic large cell lymphoma is a heterogeneous T cell disease with active pro-tumour cross-talk and immune suppressionBreast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a rare T cell lymphoma in women with textured implants. Little is known about the cell of origin (COO) and whether the tumour immune microenvironment (TIME) is critical for BIA-ALCL survival. Single-cell RNA sequencing revealed BIA-ALCL cells were heterogeneous with unique gene profiles per patient and signature genes BATF3, SERPINS, TNFSFR8, and IL2RA. The COO is a CD4+ or CD8+ memory T cell identified through rearranged TCR and gene expression. The BIA-ALCL TIME included distinct myeloid clusters, dendritic cells (DCs), and monocytes, which may support lymphoma cells. Cytokines IL-13, IL-10, TNF and secretory PDL1 were increased in BIA-ALCL seroma, indicating an immunosuppressive TIME. Interactome analysis revealed a complex network among lymphoma cells, dominated by IL-13, IL-10, and TNF members. Endogenous CD8+ T cells exhibit higher checkpoint expression than benign seromas. No clonal relationship exists between BIA-ALCL and endogenous T cells. Tissue-archetype and gene-expression analysis revealed T-cell exclusion and immunosuppressive TIME in invasive disease. In summary, BIA-ALCL cells are diverse and differ from other CD4+ T cell lymphomas. The TIME provides immunosuppressive signals to activated/exhausted T cells and homeostatic signals that promote BIA-ALCL proliferation. These new findings may offer novel therapeutic targets for advanced disease patients.2026/09/03GSE326046GSM9619758GSM9619759GSM9619778GSM9619756GSM9619757GSM9619779GSM9619776GSM9619754GSM9619777GSM9619755GSM9619774GSM9619775GSM9619753GSM9619772GSM9619773GSM9619770GSM9619771GSM9619769GSM9619767GSM9619768GSM9619765GSM9619766GSM9619763GSM9619764GSM9619761GSM9619762GSM9619760GSM96197802030130173326046Homo sapiens[42533032]