• ILK
• Rosai-Dorfman disease
• acitretin
• cutaneous Rosai-Dorfman disease
• intralesional steroid
• non–Langerhans cell histiocytosis
• pruritus
• retinoid
• sinus histiocytosis with massive lymphadenopathy

• Dermatologic pathology
• Eosinophilia
• Head and neck pathology

• Humans
• Eosinophilia/pathology
• Skin Diseases/pathology
• Neck/pathology
• Head/pathology

• Naval Medical Center San Diego

• Rosai-Dorfman disease
• breast
• extranodal RDD
• pathological diagnosis
• surgical treatment

• National Natural Science Foundation of China
• Natural Science Foundation of Shandong Province

• Case report
• Cutaneous Rosai-Dorfman
• Hematology
• Histiocytosis
• Skin

• ALK-positive histiocytosis
• Erdheim-Chester disease
• Rosai-Dorfman disease
• histiocytic sarcoma
• juvenile xanthogranuloma

• Humans
• Diagnosis, Differential
• Histiocytic Sarcoma/diagnosis
• Histiocytic Sarcoma/pathology
• Erdheim-Chester Disease/diagnosis
• Erdheim-Chester Disease/pathology
• Xanthogranuloma, Juvenile/diagnosis
• Xanthogranuloma, Juvenile/pathology

• Rosai-Dorfman disease
• cutaneous Rosai-Dorfman
• emperipolesis
• histiocytosis
• oct-2

• head and neck imaging
• magnetic resonance imaging
• neuroradiology
• oncologic imaging
• paediatric imaging

• CD68
• Rosai–Dorfman disease
• S100

• Histiocytosis
• Immunoglobulin G
• Immunoglobulin G4-related disease
• Skin

• Male
• Female
• Humans
• Adolescent
• Young Adult
• Adult
• Middle Aged
• Aged
• Histiocytosis, Sinus/diagnosis
• Immunoglobulin G/metabolism
• Retrospective Studies
• Skin Diseases/pathology
• Histiocytes
• S100 Proteins

• MEK inhibitor
• Rosai–Dorfman disease
• cutaneous Rosai-Dorfman disease
• histiocytic disorders
• methotrexate
• non-Langerhans cell histiocytosis
• trametinib

• Rosai-Dorfman-Destombes disease
• benign histiocytic proliferative
• cutaneous
• scalp
• surgery

• Adult
• Humans
• Male
• Musculoskeletal System
• Thoracic Vertebrae/diagnostic imaging

• 18F-FDG PET/CT
• Lesion identification
• Non-Langerhans cell histiocytosis
• Rosai–Dorfman disease

• Humans
• Histiocytosis, Sinus/diagnostic imaging
• Histiocytosis, Sinus/pathology
• Positron Emission Tomography Computed Tomography
• Fluorodeoxyglucose F18
• Retrospective Studies
• Positron-Emission Tomography

• National High Level Hospital Clinical Research Funding
• Chinese Academy of Medical Science Innovation Fund for Medical Sciences
• Beijing Natural Science Foundation
• National Natural Science Foundation of China

• Extranodal RDD
• Otolaryngology
• Rosai–Dorfman disease (RDD)
• Sinus histiocytosis with massive lymphadenopathy
• Treatment

• benign lymphoproliferative
• hemophagocytic lympho-histiocytosis
• intracranial neoplasms
• neuro radiology
• pet ct scan
• rosai-dorfman disease
• sinus histiocytosis with massive lymphadenopathy

• Destombes disease
• Dorfman
• IgG4-related disease
• Rosai
• pathology
• skin

Rosai–Dorfman Disease (RDD), also known as sinus histiocytosis, is included in the group of rare diseases, characterized by proliferation and accumulation of histiocytes in the lymph nodes (lymphadenopathy), most often involving the cervical ganglion chains (nodal form). RDD bone involvement is rare, estimated at 10% of cases, but primary bone involvement (extranodal form), is very rare—2–8%. Usually they are solitary lesions, with multifocal primary bone manifestations being extremely rare. Histopathological analysis is of high value for a correct diagnosis. We present the case of a Caucasian woman, 42 years old, initially treated in another clinic, for an osteolytic tumor formation in the right tibial shaft. An excisional biopsy with bone trepanation was performed, the histopathological diagnosis being the chronic inflammatory tissue. The evolution was atypical, with tumor growth, extraosseous, subcutaneous. A needle biopsy was repeated in our clinic, the result being similar to the original one. Evolution of the tumor, and the radiological and imaging aspect (periosteal reaction, eroded and thin bone cortex) suggested a more aggressive disease, these being in inconsistency with the result obtained. The biopsy was repeated, as an excision type this time. The histopathological result and immunohistochemistry indicated an RDD primary bone lesion. Based on this result, and corroborated with the data from the literature, we initiated the surgical treatment, curettage and grafting with bone substitute plus safety osteosynthesis with locked plaque, the patient registering a favorable evolution. RDD primary bone lesions are in fact an atypical manifestation of a rare disease. The correct diagnosis is very difficult due to the non-specific imaging aspect. Histopathological examination errors, especially in the case of needle biopsies can lead to errors in diagnosis and treatment with negative results for the patient.

• Rosai-Dorfman disease
• histiocytosis

• Case report
• chemotherapy
• cutaneous Rosai–Dorfman disease
• lymphoma
• myelodysplastic syndrome

• Rosai‐Dorfman disease
• histiocytosis
• lymphadenopathy
• lymphoproliferative
• neck swelling

Rosai–Dorfman disease (RDD) is a rare histiocytic proliferation of unknown etiology commonly found in children and adolescents. The common manifestation of RDD is massive and painless bilateral cervical lymphadenopathy with extranodal disease. While extranodal involvement in RDD is common, the spleen is an infrequent site of disease.

We report a 10-mo-old female infant with RDD presenting multiple splenic masses without cervical lymphadenopathy. She had fever, and blood tests showed leukocytosis, anemia, and elevated erythrocyte sedimentation rate and C-reactive protein. Ultrasound, computed tomography, and magnetic resonance images demonstrated multiple splenic masses. Despite antibiotic therapy, her symptoms were not relived. She underwent diagnostic splenectomy and was discharged with recovery.

In pediatric patients with refractory infectious symptoms or hematological abnormalities, clinicians should suspect RDD, even in patients without significant lymphadenopathy.

• Rosai–Dorfman disease
• Sinus histiocytosis with massive lymphadenopathy
• Ultrasonography
• Computed tomography
• Magnetic resonance imaging
• Case report

• Extranodal involvement
• FDG PET/CT
• Rosai-Dorfman disease

Background: Purely cutaneous Rosai-Dorfman disease (RDD) is a rare histiocytic proliferative disorder limited to the skin. To date, its pathogenesis remains unclear. Owing to recent findings of specific mutations in the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway in histiocytic proliferative disorders, it provides a novel perspective on the pathomechanism of cutaneous RDD. We aim to investigate the genomic mutations in MAPK/ERK pathway in cutaneous RDD. Methods: We retrospectively recruited all cases of cutaneous RDD from two hospitals in Taiwan from January 2010 to March 2020 with the clinicopathologic features, immunohistochemistry, and treatment. Mutations of neuroblastoma RAS viral oncogene homolog (NRAS), Kirsten rat sarcoma 2 viral oncogene homolog (KRAS), and v-raf murine sarcoma viral oncogene homolog B1 (BRAF) in MAPK/ERK pathway were investigated by the highly sensitive polymerase chain reaction with Sanger sequencing. Results: Seven patients with cutaneous RDD were recruited with nine biopsy specimens. The median age was 46 years (range: 17–62 years). Four of seven patients (57.1%) received tumor excision, while the other three chose oral and/or topical or intralesional steroids. NRAS mutation was detected in 4 of 7 cases (4/7; 51.7%), and NRAS A146T was the most common mutant point (n = 4/7), followed by NRAS G13S (n = 2/7). There is no KRAS or BRAF mutation detected. Conclusions: We report the NRAS mutation is common in cutaneous RDD, and NRAS A146T was the most frequent mutation in this cohort. Mutations in the NRAS gene can activate the RAS/MAPK signaling and have been reported to be associated with various cancers. It indicates that NRAS mutation in MAPK/ERK pathway may involve the pathogenesis of cutaneous RDD.

• BRAF
• KRAS
• NRAS
• Rosai–Dorfman
• biomarker
• genetic
• skin
• skin cancer

• dermatology
• pathology

• ich
• indeterminate cell histiocytosis
• rosacea

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.

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.

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.

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.

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.

• Rosai-Dorfman
• computed tomography
• lymphadenopathy
• magnetic resonance imaging
• paranasal sinuses

• haematological disease
• lymph nodes
• pathology, surgical

Rosai-Dorfman disease (RDD) is a rare proliferative histiocytic disorder, most commonly presenting with cervical lymphadenopathy. When extranodal, a rare manifestation of the disease is the presence of cutaneous lesions. Surgical excision has shown promising results in patients with cutaneous RDD; however, no optimal management has been elucidated. We present a 60-year-old female with recurrence of left thigh cutaneous lesions consistent with extranodal RDD whose optimal management required combined used of excision and chemotherapy.

• extranodal
• histiocytosis
• rosai dorfman

Rosai-Dorfman disease is a rare non–Langerhans cell histiocytosis. Ocular involvement is even rarer, mostly involving the orbit and eyelids, although marginal corneal ulcers, uveitis, and epibulbar masses have also been reported, and is characterized by multiple recurrences. However, the disease course and optimal treatment strategies remain undetermined, in light of the rarity of this disease.

We reported a 36-year-old male patient with the extranodal form of Rosai-Dorfman disease, presenting with scleritis and anterior uveitis in the left eye, who experienced subsequent development of an epibulbar tumor in the same eye. The patient was also complicated by a relapsing facial nodule on the right cheek. After the pathological diagnosis of Rosai-Dorfman disease was obtained, the patient underwent surgical excision of the epibulbar tumor and the facial nodule, accompanied by systemic immunosuppression therapy. At the last follow-up, the patient was asymptomatic without signs of recurrence.

This report highlights the progression of ocular manifestations of Rosai-Dorfman disease and emphasizes the importance of systemic therapy.

• Epibulbar tumor
• Histiocytosis
• Rosai-Dorfman disease

• Cutaneous Rosai-Dorfman
• Review
• Sinus histiocytosis

• Rosai-Dorfman disease
• lymphadenopathy
• sinus histiocytosis

• Células dendríticas
• Dendritic cells
• Histiocitosis
• Histiocytosis
• Immunohistochemistry
• Inmunohistoquímica
• Molecular
• Pathology
• Patología

• Dendritic Cells
• Histiocytes
• Humans
• Soft Tissue Neoplasms/pathology

• Rosai-Dorfman disease
• S100
• emperipolesis
• juvenile xanthogranuloma
• xanthogranuloma