Which feature is associated with the pagetoid reticulosis in epitheliotrophic T-cell lymphoma?

The feature associated with pagetoid reticulosis in epitheliotrophic T-cell lymphoma is the presence of neoplastic T-cells confined to the epidermis. This condition is characterized by the proliferation of atypical T-cells that primarily reside in the epidermal layer of the skin rather than infiltrating deeper tissues or other organs. The term "pagetoid" refers to the resemblance of the neoplastic cells to Paget's disease of the breast, indicating that these cells exhibit an epidermotropic pattern.

In the context of epitheliotrophic T-cell lymphoma, the neoplastic T-cells manifest in the epidermis, leading to clinical signs like erythematous plaques or patches on the skin, which can become crusted or scaly. This confined presence is significant because it influences both the clinical presentation and the approach to diagnosis and treatment of this type of lymphoma. The effective localization of neoplastic cells within the epidermis distinguishes this condition from other form of lymphomas that typically exhibit more widespread infiltration into lymph nodes or other tissues.