Rhinoscleroma associated with Rosai-Dorfman reaction of regional lymph nodes.

Rhinoscleroma is an uncommon chronic, destructive infection of the respiratory mucosa caused by Klebsiella rhinoscleromatis. This coccobacillus can be found in the typical histiocytes, the Mikulicz cells. Extranasal and nodal involvement in this disease is rare, but documented. Rosai-Dorfman disease or sinus histiocytosis with massive lymphadenopathy is also a rare, non-hereditary disorder. Bilateral cervical lymphadenopathy with emperipolesis, as the main histological characteristic, is the most common presentation. It can also occur extranodally. We report a case of rhinoscleroma occurring in a 62-year-old woman since 1984, who developed parotid gland and lymph node involvement. The changes in the nasal mucosa and the parotid gland showed chronic inflammation with Mikulicz cells. In the lymph nodes, features characteristic of Rosai-Dorfman disease were seen. Taking into consideration the literature dealing with both of these diseases, we discuss that Rosai-Dorfman disease could be a special type of lymph node reaction and is not necessarily an entity of its own. Therefore, it should be known as Rosai-Dorfman lymph node reaction. Furthermore, there seems to be an interconnection between Rosai-Dorfman disease and rhinoscleroma.