Unusual sites of Rosai-Dorfman disease in children: 5 years experience from tertiary care paediatric haemato-oncology centre.

Rosai-Dorfman disease (RDD) is a rare histiocytic disorder, usually presenting with massive lymphadenopathy. The involvement of extra nodal sites, bone and nodal sites like mediastinum are rare. Clinical data of three cases of extra nodal RDD who were admitted in our paediatric haemato-oncology unit were analysed in the last 5 years. The extra nodal RDD (maxillary sinus, nasal pharyngeal focus, and external auditory meatus) were diagnosed based on histopathology and positron emission tomography scan. They were treated with steroids but were refractory hence requiring salvage chemotherapy. Currently all three of them are in complete remission. Extra nodal RDD is difficult to diagnose, histopathology and radiology play an important role. Here, we present three cases, of which two were steroid-refractory which were treated with salvage chemotherapy and are in complete remission.