Langerhans' cell histiocytosis in association with periapical granulomas and cysts.

This report describes a series of six cases of inflammatory periapical disease with small aggregates of Langerhans cells as a minor component. Immunohistochemical findings confirm that the cells are phenotypically related to Langerhans cells. Aggregates of these cells are not normally found in radicular cysts or periapical granulomas and have been interpreted to represent chronic localized Langerhans' cells histiocytosis. Whether these lesions, which arise within the context of chronic inflammatory periapical disease, represent incipient eosinophilic granulomas or are a more benign, minimally destructive form of Langerhans' cell histiocytosis is unknown. Clinical follow-up suggests that these lesions remain localized and that curettage is adequate treatment.