Histology of primary cutaneous marginal zone lymphoma (PCMZL)

Low-power (A) and high-power (B) photomicrographs of diffuse non-epidermotropic dermal infiltrate of primary cutaneous marginal zone lymphoma. (C) Malignant cells stain as CD79a+ B cells (D) with infiltrating non-neoplastic CD3+ T cells. (E) The subepidermal infiltrate reveals clusters of plasma cells with monotypic expression of kappa light chains, while (F) staining for lambda light chains is negative.