Table 2: Summary of the common histologic findings for the main subtypes of primary cutaneous B-cell lymphoma.

 

PCDLBCL-LT

PCFCL

PCMZL

Histology

Diffuse non-epidermotropic infiltrates; commonly sheets of monotonous large rounded cells; many mitotic figures are common

Nodular or diffuse non-epidermotropic infiltrates

consisting of monotonous follicular cells

Nodular or diffuse non-epidermotropic infiltrates

Cyto-pathology

Centroblasts and immunoblasts; small B-cells and reactive T-cells are rare

Centrocytes with centroblasts and immunoblasts; admixed with follicular dentritic cells and numerous reactive T-cells; follicular architecture often ill-defined

Lymphocytes, marginal zone B-cells, centrocyte-like cells, plasma cells, centroblasts, immunoblasts, and lymphoplasmacytic cells; reactive T-cells and germinal centers

PCDLBCL-LT: primary cutaneous diffuse large B cell lymphoma- leg type; PCFCL: primary cutaneous follicle center lymphoma; PCMZL: primary cutaneous marginal zone lymphoma [3, 4].