Introduction: Rosai-Dorfman disease (RDD) is a rare benign histiocytic proliferation, characterized by a group of clinical symptoms. This report presents a case of extranodal RDD manifesting as a progressively enlarging left maxillary mass in a 42-year-old woman. Surgical exploration and biopsy confirmed the diagnosis of RDD, with characteristic histopathological features including emperipolesis. Treatment involved corticotherapy, resulting in controlled maxillary pain and improvement of the disease after one year. This case underscores the potential for extra-nodal RDD presentations, posing diagnostic challenges and emphasizing the importance of considering RDD in the differential diagnosis of maxillary masses.

Rosai-Dorfman disease (RDD), also known as sinus histiocytosis with massive lymphadenopathy, is an uncommon benign disorder characterized by the accumulation of activated histiocytes in affected tissues. While RDD typically involves lymph nodes, it may manifest as extranodal involvement. Breast involvement is an exceedingly rare presentation of this condition with <100 reported cases worldwide. This report presents a case of RDD in a 58-year-old male patient who presented with a palpable breast mass. Mammography and ultrasound imaging studies raised concerns for malignancy, prompting a breast biopsy. Histopathological examination revealed S100-positive pale histiocytes exhibiting emperipolesis, consistent with RDD. The management of extranodal RDD is individualized, as no standardized guidelines are currently available. However, surgical excision is recommended for unicentric breast lesions, which was performed in our case, resulting in complete remission. The patient has remained disease-free under surveillance with computed tomography scans. Our case underscores the importance of considering RDD in the differential diagnoses of breast masses and highlights the utility of surgical excision as an effective treatment option, especially for unicentric breast lesions of RDD.

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.

An 81-year-old man presented with anemia, fatigue, weight loss, and recurrent urinary tract infections and was found to have diffuse large adenopathy and infiltrating renal masses. Surgical excision of a lymph node and histologic evaluation led to the diagnosis of Rosai-Dorfman disease, a rare histioproliferative condition that classically presents with enlarged cervical lymph nodes bilaterally. It also can involve additional nodal chains and/or have extranodal manifestations. The condition can self-resolve or have periods of remission and reactivation.

We report a case of a 49-year-old female diagnosed with extranodal multifocal Rosai-Dorfman disease (RDD) of the breast using mammography and ultrasound. RDD is a rare non-Langerhans cell benign proliferative disorder of histiocytes that usually involves the lymph nodes, but may involve extranodal sites. We review the clinical presentation as well as imaging features of this rare disease on multiple modalities and the importance of recognizing the diagnosis in order to direct treatment.

Rosai-Dorfman Disease (RDD), or sinus histiocytosis with massive lymphadenopathy, is a rare entity characterized by proliferating S100-positive histiocytes. It is most commonly found in lymph nodes with extranodal involvement usually occurring in the head and neck. Pancreatic involvement is extremely rare. The pathology department archives were searched for fine needle aspirations and pancreatic resections showing evidence of RDD. Clinicopathologic features, cytologic smears, cell blocks, immunocytochemical stains and surgical resections were reviewed. Three cases were identified. They were all females, aged 65, 69 and 75, with involvement of the pancreatic tail or head by solid masses of median size 2.3 cm (range 2.1-4.5 cm). Cytologic findings on smears included multiple histiocyte clusters resembling loosely cohesive epithelioid granulomas, singly dispersed histiocytes with moderate to marked nuclear atypia and characteristic emperipolesis. These atypical histiocytes stained positively for CD68, CD163 and S100. Smear background contained variable mixed inflammatory cells, necrotic debris and stromal fragments. The RDD diagnosis was further confirmed on pancreatic resection in two patients and core biopsy in one. The latter patient required three separate procedures before a definitive diagnosis was made. RDD of pancreas is a rare benign inflammatory condition that is diagnostically challenging on cytology. This can cause delays in cytologic diagnosis and/or misdiagnosis. Identification of characteristic cytologic features, primarily histiocytes with emperipolesis, and matching immunocytochemical profile can ensure accurate diagnosis and distinction from mimics.

UNASSIGNED: Rosai-Dorfman disease (RDD) is a rare lympho-histiocytic disorder of indeterminate etiology usually presenting with lymph node involvement, and infrequently with extra-nodal manifestations. The diagnosis of this condition is challenging due to the wide spectrum of disease manifestations.
UNASSIGNED: To elucidate the radiologic features of this disease using multimodality imaging in histopathologically proven cases and to identify characteristic features that would enable its differentiation from its mimics.
UNASSIGNED: We retrospectively evaluated imaging studies of 19 patients with histopathologically confirmed RDD presenting to our institute between January 2004 and March 2016. Imaging modalities included magnetic resonance imaging (MRI), computed tomography, FDG-positron emission tomography (PET) CT, mammography, and ultrasonography.
UNASSIGNED: Lymphadenopathy was the most common imaging feature in our study, seen in 11 (57.8%) cases followed by sino-nasal involvement in 7 (36.8%) cases and intracranial masses in 5 (26.3%) cases. Bilateral homogeneously enhancing cervical lymphadenopathy with avidity on FDG-PET scans was the predominant abnormality on imaging. Sino-nasal involvement manifested as homogeneously enhancing soft-tissue masses occupying the paranasal sinuses. Intracranial disease manifested as sellar/suprasellar masses, dural-based lesions along the cerebral hemispheres and choroid plexus enlargement. Unusual disease manifestations included spinal, osseous, and breast lesions.
UNASSIGNED: Due to the high likelihood of multifocal involvement, the recognition of RDD at one site necessitates screening of other sites for disease. Homogeneously enhancing, FDG-avid lymphadenopathy and sino-nasal masses in association with hypointense extra-nodal lesions on T2-weighted MRI are imaging features which could aid the diagnosis of RDD and facilitate its differentiation from pathologies that present in a similar manner.

OBJECTIVE: To report a case of Rosai-Dorfman disease (RDD) presenting as a solitary, choroidal mass, initially suspicious for uveal melanoma, in a 72-year-old woman.
METHODS: Retrospective case report of a single patient.
RESULTS: A 72-year-old woman presented with sudden vision loss in the right eye. A month prior, visual acuity was 20/40, but she was noted to have a choroidal mass confirmed with B-scan ultrasonography. Patient\'s vision deteriorated significantly a month later and a shallow retinal detachment was newly noted. Magnetic resonance imaging was obtained, demonstrating a hyperintense intraocular tumor on TI imaging. Patient underwent enucleation of the right eye for suspicion of a uveal melanoma. Pathology revealed a mixed cellular infiltrate with histiocytes, some exhibiting emperipolesis. Macrophage immunohistochemical stains were positive, while melanocytic markers were negative. A diagnosis of RDD was made. Subsequently, the patient had a negative workup for systemic involvement. A final diagnosis of intraocular RDD without extraocular and systemic involvement was determined.
CONCLUSIONS: We describe a rare presentation of RDD as a solitary choroidal mass in an elderly patient with overlapping features of uveal melanoma. Definitive diagnosis could only be made on histology. RDD should be considered in the differential diagnosis of a choroidal lesion in the elderly.

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.