Study of the reactive dendritic cells in small B-cell lymphoproliferations of the skin

Abstract

Distinguishing between low-grade primary cutaneous B-cell lymphoma (LG-pCBCL) and cutaneous lymphoid hyperplasia (CLH) based on histological features is often difficult. CLH lesions contain numerous reactive cells of the histiocyte lineage [Langerhans cells (LC), dermal dendritic cells (DDC), and macrophages], which are also often present in CBCL. The aim of this study was to determine whether immunohistochemical detection of those cells could help differentiate between CLH and LG-pCBCL. We determined the percentages of those histiocytic cells in the dermal infiltrates of 45 cases of cutaneous lymphoproliferations comprising 16 CLH and 29 LG-pCBCL (19 follicle-center cell lymphomas and 10 marginal zone lymphomas) by immunohistochemical labeling with antibodies to CD1a, FXIIIa, and CD68 to respectively detect LC, DDC, and macrophages. To avoid observer-dependent bias, an automated morphometric analysis method was used to recognize immunoreactive cells and calculate their percentages within the infiltrate. FXIIIa(+) cells were significatively more frequent in CLH than in LG-pCBCL, whereas CD1a(+) and CD68(+) cell frequencies were comparable in the two groups. The results of our study suggest that DDC might play an important role in the genesis of cutaneous lymphomas.

A study of histologic and immunophenotypical staining patterns in cutaneous lymphoid hyperplasia

“…Cutaneous lymphoid hyperplasia contains numerous reactive cells of the histiocytic lineage (Langerhans cells, dermal dendritic cells, and macrophages). 27,29 This was also demonstrated in our study by immunostaining for S-100 protein, CD1a, and CD68. Interestingly, only FXIIIa1 cells were recently shown to be significantly increased in CLH compared with low-grade primary CBCL.…”

“…Interestingly, only FXIIIa1 cells were recently shown to be significantly increased in CLH compared with low-grade primary CBCL. 27 S-100-, CD1a-, and CD68-positive cells were not found to be a discriminating histologic feature, although the authors did not indicate the histologic features and subtypes of their 16 CLH cases.…”

Primary cutaneous lymphoma: two-decade comparison in a population of 263 cases from a Swiss tertiary referral centre

“…As discussed by Kazakov et al and several other authors, the diagnosis of PCMZL can be challenging and can erroneously include cases with pseudolymphomatous reactions. [13][14][15][16] This may mean that several patients were diagnosed with pseudolymphoma, especially between 1990 and 1999, and were therefore not seen as lymphomas in our department. Concerning the pattern of CBCL subtypes, international data are discordant.…”

Dermal infiltrates of cutaneous T‐cell lymphomas with epidermotropism but not other cutaneous lymphomas are abundant with langerin+ dendritic cells

“…demonstrated almost no CD1a staining in the infiltrates of CBCLs in contrast to pseudolymphomas and suggested that this fact could help distinguishing these two disorders 21 . In contrast, in other studies no difference could be found between cutaneous pseudolymphomas and B‐cell lymphomas 10,22 …”