Woringer-Kolopp Disease (Localized Pagetoid Reticulosis) or Unilesional Mycosis Fungoides?

Abstract

The controversial nosology of Woringer-Kolopp disease (localized pagetoid reticulosis, unilesional mycosis fungoides) is being clarified by the systematic immunophenotypic and immunogenetic examination of infiltrating lesional T lymphocytes. The clinical course and immunohistochemical characteristics of eight cases of Woringer-Kolopp disease are described. Lesions measured 0.8 x 0.5 to 16.0 x 15.0 cm. Histologically, all cases resembled mycosis fungoides-type cutaneous T-cell lymphoma and phenotypic analysis supported their designation as an epidermotropic T-cell process. Phenotypic aberrancy was not noted on immunohistochemical analysis of paraffin-embedded tissue. Three of four patients with available fresh-frozen tissue specimens demonstrated reduced or absent expression of CD7 (Leu-9) and/or Leu-8, while loss of the pan-T-cell markers CD2, CD3, and CD5 was not observed. Only in half these patients was a lesional predominance of CD4+ T-cells revealed. Germline DNA was detected in a lesional skin specimen obtained from one patient tested for T-cell receptor gene rearrangements. After treatment, the observation of disease-free periods ranging from 18 months to 17 years (mean, 5.9 years) reinforces the view that Woringer-Kolopp disease is a focal pathologic event with a favorable prognosis. No patient experienced a local recurrence or distant spread of the disease. This and previous studies suggest that Woringer-Kolopp disease is a unique, benign unilesional T-cell lymphoproliferative process with certain histologic and phenotypic similarities to both early epidemotropic mycosis fungoides-type cutaneous T-cell lymphoma and other T-cell lymphoproliferations.