Figure 6.

Histological aspect of primary cutaneous diffuse large B-cell lymphoma, leg type. (a) Diffuse and dense infiltrate throughout the dermis ad subcutis separated from the epidermis by a Grenz zone. (b) The infiltrate is mainly consisting of confluent sheets of large B-cells with roundish nuclei, prominent nucleoli, and open chromatin resembling centroblasts and immunoblasts. (c and d) Primary cutaneous diffuse large B-cell lymphoma, leg type is usually characterized by strong CD20 positivity and a high proliferation rate (Ki-67 > 70%) and BCL-6, CD5, CD10, CD30, CD138, and cyclin D1 negativity