Primary cutaneous follicular lymphoma, PCFCCL

Definition

A primary lymphoma of skin showing neoplastic follicles with the cytomorphology and immunophenotype (CD10 or bcl-6 positivity) of follicle centre cells. There should be no extracutaneous lymphoma at the time of diagnosis or for a time thereafter (6 months according to references 4 and 7).

Epidemiology

Patients have a median age of about 60 years, similar to the average for secondary cutaneous follicular lymphoma4. Disease before the age of 40 years is rare4.

Clinical features

Occur most frequently on the head and neck, as does secondary cutaneous follicular lymphoma2. It presents as solitary or grouped papules, plaques or tumours. Some patients have a long history of "pseudolymphoma"4.

Histopathology

Neoplastic follicles are seen in the dermis in at least part of the infiltrate. The lymphoid population consists of centrocytes (small and large cleaved follicle centre cells) and a variable number of centroblasts (large non-cleaved follicle centre cells with prominent nucleoli)4. There is usually a Grenz zone1,2 separating the infiltrate from the epidermis, although in some cases epidermotropic T-cells may be present1. The infiltrate may be "top heavy" or "bottom heavy" and may infiltrate the subcutis to a variable extent4. The neoplastic follicles may have mantles that are thick, thin or discontinuous4. The mantle cells may infiltrate the follicles to impart a "floret-like" pattern4. Rarely, reactive follicles may also be present1,2. There may be a diffuse neoplastic component, which is usually low grade but may take the form of DLBCL (in the WHO classification, see A study comparing primary and secondary cutaneous large B-cell lymphomas).

Immunohistochemistry

The EORTC defined PCFCCL as CD10-/bcl-2-, not associated with the t(14;18): others do not apply this definition.

	Primary cutaneous follicular lymphoma		Secondary cutaneous follicular lymphoma
CD3		reactive T-cells positive
CD5	0/161
CD10	13/161, 13/152, 27/304, 29/327		30/314
CD20	16/161, 18/182,
CD21		FDCs positive1,2
CD23	6/161	FDCs positive1,2
CD43	4/16(all 4 cases weak)1, 6/112
CD79a	18/182
bcl-2	13/16(weak in 5 cases)1, 9/152 , 0/52, 17/304, 13/327		31/314
bcl-6	16/161, 15/152, 28/284, 31/327		28/284

PCR analysis for t(14;18) was negative in all but 16 of 87 cases (0/141, 0/102, 0/43, 1/146, 4/134, 11/327). Positivity occurs in systemic FL with cutaneous involvement (3/43,10/134).

Differential diagnosis

Systemic FL with cutaneous involvement; suggested by presence of t(14;18). Thorough staging is required. PCFCCL is more often grade 3, more likely to have a disrupted but thick mantle and more likely to show a floret pattern4.
Primary cutaneous diffuse large B-cell lymphoma: a diffuse infiltrate of centroblasts and immunoblasts.

Prognosis

Compared with nodal follicular lymphoma, there appears to be a higher remission rate , albeit with a high relapse rate in skin or lymph nodes1,2 and good overall survival. 5-year survival is 89-97%4,5. A diffuse large cell histology and strong positivity for bcl-2 may be associated with a worse prognosis5, although others have not found this7.

References

1 Goodlad, J.R., Krajewski, A.S., Batstone, P.J., McKay, P., White, J.M., Benton, E.C., Kavanagh, G.M. and Lucraft, H.H. Primary cutaneous follicular lymphoma: a clinicopathologic and molecular study of 16 cases in support of a distinct entity. Am J Surg Pathol 2002;26:733-41.

2 Franco, R., Fernandez-Vazquez, A., Rodriguez-Peralto, J.L., Bellas, C., Lopez-Rios, F., Saez, A., Villuendas, R., Navarrete, M., Fernandez, I., Zarco, C. and Piris, M.A. Cutaneous follicular B-cell lymphoma: description of a series of 18 cases. Am J Surg Pathol 2001;25:875-83.

3 Child, F.J., Russell-Jones, R., Woolford, A.J., Calonje, E., Photiou, A., Orchard, G. and Whittaker, S.J. Absence of the t(14;18) chromosomal translocation in primary cutaneous B-cell lymphoma. Br J Dermatol 2001;144:735-44.

4 Kim BK, Surti U, Pandya A, et al. Clinicopathologic, immunophenotypic, and molecular cytogenetic fluorescence in situ hybridization analysis of primary and secondary cutaneous follicular lymphomas. Am J Surg Pathol 2005; 29:69-82

5 Campo E, Chott A, Kinney MC, et al. Update on extranodal lymphomas. Conclusions of the Workshop held by the EAHP and the SH in Thessaloniki, Greece. Histopathology 2006; 48:481-504 FULL TEXT

6 Volkenandt M, Cerroni L, Rieger E, et al. Analysis of the 14;18 translocation in cutaneous lymphomas using the polymerase chain reaction. J Cutan Pathol 1992; 19:353-6

7 Mirza I, Macpherson N, Paproski S, et al. Primary cutaneous follicular lymphoma: an assessment of clinical, histopathologic, immunophenotypic, and molecular features. J Clin Oncol 2002; 20:647-55

This page last revised 28.4.2006.