Regressing atypical histiocytosis, a regressing cutaneous phase of Ki-1-positive anaplastic large cell lymphoma. Immunocytochemical, nucleic acid, and cytogenetic studies of a new case in view of current opinion

Abstract

Background: Regressing atypical histiocytosis is a rare multifocal cutaneous tumor characterized by large, spontaneously regressing, ulcerating skin nodules. Although initially self-remitting, the condition may progress to systemic lymphoma.

Methods: Using material from one patient, an attempt was made to clarify the nature of this condition with immunophenotyping, genotyping, and chromosome studies.

Results: Immunophenotyping studies indicated the condition was of T-cell lineage, although T-cell receptor gene studies showed polyclonal rearrangement. This case progressed to systemic lymphoma.

Conclusions: The authors believe regressing atypical histiocytosis is a regressing phase of Ki-1-positive anaplastic large cell lymphoma of the skin.