Differentiation Between Malignant B‐Cell Lymphomas and Pseudolymphomas of the Skin

Abstract

Among cutaneous pseudolymphomas (PL) in a strict sense, in which the etiology is largely unknown, B-cell types, simulating malignant B-cell lymphoma, and T-cell types, simulating malignant T-cell lymphoma of the skin, can be differentiated. Criteria favoring a pseudolymphomatous rather than a malignant lymphoid infiltrate of B-cell type may be clinical (solitary lesion on the head), histologic (wedge-shaped infiltrate with follicle formation and sharply demarcated germinal centers), or cytomorphologic (polymorphous infiltrate showing an admixture of great numbers of macrophages, plasma cells, and eosinophils). Additional information can be provided by enzymophenotyping of the cells, showing the typical starry-sky pattern of the macrophages in pseudolymphomatous infiltrates, and by the demonstration of the polyclonality of the lymphoid cells in pseudolymphomas with respect to surface markers and intracytoplasmatic Ig production, as shown by immunophenotyping techniques.

Alkaline Phosphatase Positive Lymphoma

“…Recognition of the common origin makes it acceptable that intermediate forms may occur. The fact that all our APpositive cases bind EAC makes them related to germinal center cell lymphoma, since B-CLL and well-differentiated lymphocytic lymphoma are negative or only weakly posi tive for EAC [19], The one lymphoplasmacytoid immunocytoma case in our series of several biopsies shows histologically an evo lution from lymphoplasmacytoid immuno cytoma to polymorphic immunocytoma with the formation of some germinal centers. This represents the differentiation of the B lymphocytic clone and can be seen as a borderline case between centroblastic-centrocytic lymphoma and immunocytoma.…”

LOCALIZED FORM OF LYMPHOMATOID PAPULOSIS, EVALUATING ING IN T-CELL LYMPHOMA – Case Report

“…Some authors have started that in 10-20% of the cases , the patients could be evolve in Lymphoma or primary giant -cell anaplastic T-cell Lymphoma . In rare cases the disease could evolve in Mycosis fungoides (1,2).…”

A Morphologic Study of Lymphadenosis benigna cutis

“…Burg et al [1982] stressed that fully developed second ary follicles are present in only 10% of the le sions at the time of biopsy. Since germinal centers are fluctuating structures with a characteristic phasic course it is possible that only in some period of the development of pseudolymphoma the germinal centers are an essential part of lymphadenosis benigna cutis.…”