Overview of previously and currently used classification systems for cutaneous lymphomas and clinicopathologic features of the different CBCL entities
| . | Previous and current classifications . | ||
|---|---|---|---|
| EORTC 1997 | PCI/ PCMZL | PCFCCL | PCLBCL of the leg |
| WHO 2001 | EMZL | cFCL | DLBCL |
| DLBCL | |||
| WHO-EORTC 2005 | PCMZL | PCFCL | PCLBCL, LT |
| WHO 2008 | EMZL | PCFCL | PCLBCL, LT |
| Clinicopathologic features | |||
| Clinical features | Solitary or multiple papules, plaques, or nodules preferentially localized on the extremities | Solitary or grouped tumors presenting on the head or on the trunk | Solitary or multiple tumors presenting mainly on the leg(s) and rarely at other sites |
| Sometimes associated with Borrelia burgdorferi infection | Cutaneous relapses in 20% | Frequent relapses and extracutaneous dissemination | |
| Frequent cutaneous relapses | Extracutaneous dissemination in 5% to 10% | ||
| Rarely extracutaneous dissemination | |||
| Histopathology | Patchy or diffuse infiltrates composed of small B cells, including marginal zone (centrocyte-like) cells, lymphoplasmacytoid cells, and plasma cells | Follicular, follicular and diffuse, or diffuse infiltrates composed of neoplastic follicle center cells, usually a mixture of centrocytes and variable numbers of centroblasts | Diffuse infiltrates with a predominance or confluent sheets of of centroblasts and immunoblasts |
| Immunophenotype | Monotypic cIg, CD79a+, Bcl-2+, CD5−, cyclin D1−, Bcl-6−, CD10−, MUM-1+ (on plasma cells) | Monotypic sIg or absence of sIg, CD20+, CD79a+, Bcl-6+, Bcl-2−, MUM-1−, CD10±, FOXP1−(±) | Monotypic sIg and/or cIg, CD20+, CD79a+, Bcl-6+(−), CD10−, Bcl-2+, MUM-1+, FOXP1+ |
| Prognosis | 5-year survival: > 95% | 5-year survival: 95% | 5-year survival: 50% |
| . | Previous and current classifications . | ||
|---|---|---|---|
| EORTC 1997 | PCI/ PCMZL | PCFCCL | PCLBCL of the leg |
| WHO 2001 | EMZL | cFCL | DLBCL |
| DLBCL | |||
| WHO-EORTC 2005 | PCMZL | PCFCL | PCLBCL, LT |
| WHO 2008 | EMZL | PCFCL | PCLBCL, LT |
| Clinicopathologic features | |||
| Clinical features | Solitary or multiple papules, plaques, or nodules preferentially localized on the extremities | Solitary or grouped tumors presenting on the head or on the trunk | Solitary or multiple tumors presenting mainly on the leg(s) and rarely at other sites |
| Sometimes associated with Borrelia burgdorferi infection | Cutaneous relapses in 20% | Frequent relapses and extracutaneous dissemination | |
| Frequent cutaneous relapses | Extracutaneous dissemination in 5% to 10% | ||
| Rarely extracutaneous dissemination | |||
| Histopathology | Patchy or diffuse infiltrates composed of small B cells, including marginal zone (centrocyte-like) cells, lymphoplasmacytoid cells, and plasma cells | Follicular, follicular and diffuse, or diffuse infiltrates composed of neoplastic follicle center cells, usually a mixture of centrocytes and variable numbers of centroblasts | Diffuse infiltrates with a predominance or confluent sheets of of centroblasts and immunoblasts |
| Immunophenotype | Monotypic cIg, CD79a+, Bcl-2+, CD5−, cyclin D1−, Bcl-6−, CD10−, MUM-1+ (on plasma cells) | Monotypic sIg or absence of sIg, CD20+, CD79a+, Bcl-6+, Bcl-2−, MUM-1−, CD10±, FOXP1−(±) | Monotypic sIg and/or cIg, CD20+, CD79a+, Bcl-6+(−), CD10−, Bcl-2+, MUM-1+, FOXP1+ |
| Prognosis | 5-year survival: > 95% | 5-year survival: 95% | 5-year survival: 50% |
PCI indicates primary cutaneous immunocytoma; PCMZL, primary cutaneous marginal zone lymphoma; PCFCCL, primary cutaneous follicle center cell lymphoma; PCLBCL of the leg, primary cutaneous large B-cell lymphoma of the leg; EMZL, extranodal marginal zone lymphoma; cFCL, cutaneous follicle center lymphoma (for cases with a follicular or follicular-diffuse growth pattern); DLBCL, diffuse large B-cell lymphoma (for cases with a diffuse growth pattern); PCFCL, primary cutaneous follicle center lymphoma; and PCLBCL, LT, primary cutaneous diffuse large B-cell lymphoma, leg type.