We report the first known cases of iTCL-GI presenting with cutaneous manifestations, which proved critical for identifying secondary disease involvement.
Case 1: A 29-year-old woman with limited cutaneous systemic sclerosis presented with chronic diarrhea, rapidly progressive oral ulcerations, and subtle papules on the back and arm. Colon, oral, and skin biopsies revealed a CD8+-cytotoxic clonal T-cell infiltrate with aberrant loss of CD5 and CD7, identical to the clone observed in an ileal biopsy from 2018. The palate biopsy was distinct, showing large, atypical lymphocytes with Ki-67 >90%, reflecting localized transformation to PTCL-NOS. Laboratory studies demonstrated identical TCR rearrangements across all sites. Imaging showed FDG-avid mucosal disease without nodal involvement. She received multiple systemic therapies followed by haploidentical hematopoietic stem cell transplantation and remains in remission two years later.
Case 2: A 62-year-old woman with intermittent gastrointestinal symptoms developed erythematous patches and annular plaques on the trunk. Duodenal and ileal biopsies showed a CD4−/CD8− infiltrate with low Ki-67 and clonal TCRγ/β rearrangements, findings later confirmed in a skin biopsy. ImagingFDG PET/CT showed low-grade mild FDG bowel uptake with small mesenteric nodes. Peripheral blood flow cytometry initially showed a minor abnormal T-cell population, which was undetectable on repeat testing as skin lesions largely resolved, reinforcing the indolent nature of the disease.
Cutaneous manifestations of iTCL-GI may precede or parallel gastrointestinal involvement,, reflecting a continuum from indolent lymphoproliferative disease to transformation. Emerging data implicate JAK–STAT pathway alterations as potential drivers and therapeutic targets. These cases underscore the importance of multidisciplinary recognition of subtle extraintestinal disease.
