Unusual presentation of extranodal Rosai-Dorfman disease: A scalp lump

Rosai-Dorfman disease (RDD) is a benign and idiopathic proliferative histiocytic disorder that typically manifests with extensive cervical lymphadenopathy, fever, polyclonal gammopathy, and leukocytosis with neutrophilia. However, the purely cutaneous variant of RDD is exceptionally uncommon, occurring in only 3% of all RDD cases. In this abstract, we present a rare case of RDD exhibiting a purely cutaneous form. The patient, a 40-yearold male, presented with a scalp lump. Diagnostic investigations, including histopathological examination, confirmed the diagnosis of RDD. No lymphadenopathy or systemic involvement was detected, highlighting the uniqueness of the cutaneous presentation. The rarity of pure cutaneous RDD underscores the significance of reporting such cases to enhance our understanding of the diverse clinical manifestations of this condition. Awareness of this atypical presentation is crucial for accurate diagnosis and appropriate management, as the treatment approach for purely cutaneous RDD may differ from the more common systemic forms. Through this case report, we aim to contribute to the existing medical literature on RDD, emphasizing the need for careful evaluation of skin lesions to include RDD in the differential diagnosis, even in the absence of lymphadenopathy or systemic symptoms. Further research and documentation of similar cases will undoubtedly advance our knowledge of this intriguing disease and aid clinicians in providing optimal patient care.