INFLAMMATORY PSEUDOTUMOR AND ROSAI-DORFMAN DISEASE OF SOFT-TISSUE - AHISTOLOGICAL CONTINUUM

A lesion of the chest wall in a 34 year old woman, which had a combina tion of histological and immunophenotypic features of inflammatory pse udotumor and Rosai-Dorfman disease of soft tissue, is described, There was considerable overlap in the pathogenesis, histology and immunophe notype of these two lesions. The similarities between these two lesion s suggest that there is a temporal sequence and a histological continu um with early histiocyte-rich and late fibroblast- and myofibroblast-r ich lesions, Alternatively, the morphological and immunophenotypic fea tures could be because of aberrant cytokine expression in an inflammat ory pseudotumour, resulting in transformation of histiocytes to resemb le those seen in Rosai-Dorfman disease.