A systematic literature review revealed 88 Rosai-Dorfman Disease (RDD) cases affecting the orbit. We present a review of the literature on orbital RDD in addition to two brothers with isolated bilateral extra-nodal orbital RDD cases associated with G-6PD deficiency. The disease manifested as asymmetric extensive orbital and paranasal sinus infiltration, with orbital bone destruction. Orbital mass debulking and steroids improved the condition in both patients. This is the most extensive case series of orbital RDD reported, including clinical manifestation, imaging, pathologic results, management, and outcome. Vigilant follow-up is essential to monitor for potential malignant transformation, systemic manifestations, potential vision loss, or life-threatening recurrences.

Rosai-Dorfman Disease (RDD), also known as sinus histiocytosis with massive lymphadenopathy, is an uncommon histiocytic condition characterized by massive histopathological aggregation of CD1-a negative, CD68-positive, and S100-positive histiocytes. It was initially described by Destombes in 1965 under the term \"adenitis with lipid excess.\" However, it is named after Rosai and Dorfman who reported further histopathological features of the disease in 1969. The diagnosis of this non-Langerhans cell histiocytosis can be challenging and requires high clinical suspicion. The diagnostic process usually involves imaging, tissue biopsies, and genetic testing as needed. In this case series, we are presenting three cases of rare disease. Case 2 had both nodal and extranodal forms, which makes this case rarer than cases 1 and 3, which present with extranodal lesions.

Rosai-Dorfman disease (RDD), otherwise known as sinus histiocytosis with massive lymphadenopathy (SHML), is a very rare and typically benign disorder of unknown etiology with <10% bone involvement. The report is of a case seen at the authors\' hospital of a patient presenting with several months\' onset unspecified nontraumatic ankle pain. There was no physical mass or lymphadenopathy appreciated on examination. Plain radiographs and magnetic resonance images demonstrated an osteolytic lesion at the medial malleolus. Biopsy revealed the diagnosis of intraosseous manifestation of Rosai-Dorfman disease.

Rosai-Dorfman disease (RDD) is a rare usually self-limited non-Langerhans cell histiocytosis of unknown etiology. Nodal and extranodal RDD appear to represent distinct conditions with different molecular alterations and prognosis. They also pose different diagnostic challenges on biopsies and fine-needle aspiration (FNA) cytology. The aim of this study was to report on 3 cases of intra-abdominal RDD and perform an extensive review of the literature on FNA findings of RDD.
We reviewed FNA specimens from cases diagnosed histologically or cytologically as RDD during the past 10 years. We searched the PubMed and Google Scholar databases for cases of RDD sampled by FNA.
We identified 3 cases of intra-abdominal RDD, involving the kidney, periportal lymph node, and pancreas. FNA of the latter was hypocellular with fibrosis and was nondiagnostic. FNA of the first 2 yielded hypercellular smears that were diagnosed as RDD due to the identification of emperipolesis occurring in large uni- or binucleated histiocytes with large nuclei, fine chromatin, and prominent nucleoli in smears and cell-block sections. Immunohistochemistry showed positive staining for S100 and CD68 and negative staining for CD1a. The large histiocytes with emperipolesis were more difficult to identify histologically and their demonstration required immunohistochemical stains.
Our experience and an extensive review of the literature suggest that extranodal RDD can be diagnosed on FNA, and that the recognition of histiocytes with emperipolesis may be less challenging cytologically than histologically. The fibrosis frequently seen in extranodal RDD may lead to nondiagnostic aspirates, however.

OBJECTIVE: Intra ocular Rosai-Dorfman disease (RDD) is an extremely rare disease. We are reporting the first case of RDD presenting as ciliary body mass mimicking ciliary body melanoma, and we are reviewing the English literature reporting on cases of RDD presented with intraocular disease.
METHODS: An 18-year-old lady presented with loss of vision in the right eye, and was found to have intraocular mass lesion. She was diagnosed clinically and radiologically as a case of ciliary body melanoma associated with total retinal detachment.
RESULTS: Histopathological sections and stains proved to be intraocular RDD. Review of the literature revealed three cases of intraocular RDD; two of them had choroid thickening associated with serous retinal detachment, and one presented with intraocular mass mimicking choroid melanoma. Two of the three cases were enucleated. Our case is the first case in English literature of intraocular ciliary body RDD, mimicking ciliary body melanoma.
CONCLUSIONS: RDD can present as an intraocular mass that mimics ciliary body melanoma. This case emphasizes the importance of diagnostic biopsy before considering the final therapy in unclear cases, mainly when associated with unusual systemic features like lymphadenopathy.

Rosai-Dorfman disease (RDD), otherwise known as sinus histiocytosis with massive lymphadenopathy, is a rare disease. Cutaneous RDD (CRDD) is an extremely rare form of RDD, which is limited to the skin. The present study examined a case of purely CRDD in a 25-year-old female patient who presented with a two-month history of red plaques on her face. In addition, a review of the literature was conducted, where the etiology, pathology, clinical characteristics and treatment of the disease were discussed. From a dermatological perspective, the current study aimed to emphasize the histological features and clinical morphology of cutaneous RDD. Clinicians should have sufficient knowledge to be able to recognize and manage this rare condition. The present study found that the presence of reddish-yellow nodules on the face without any particular sensitivity may be useful in the diagnosis of CRDD. Treatment with topical steroids was found to be beneficial in alleviating CRDD.