Consensus recommendations for the diagnosis and clinical management of Rosai-Dorfman-Destombes disease

Rosai-Dorfman disease mimicking cavernous hemangioma: a case report

A 31-year-old female presented to the clinic with a 2 year history of proptosis of the right eye. She was diagnosed with cavernous hemangioma during her initial ophthalmologic consult and was advised monitoring. However, after a considerable increase in proptosis, she underwent an excision biopsy of the right orbital mass. A diagnosis of Rosai Dorfman disease was made after the histopathology report revealed a fibrosclerotic tissue with histiocytic proliferation showing emperipolesis that is mixed with numerous small lymphocytes and plasma cells. Rosai Dorfman disease is a rare disease presenting with lymphadenopathy and sinus histiocytosis. Orbital involvement can be the principal manifestation with proptosis as the most common presentation. Resection of the orbital lesion helped in the resolution of the mild ophthalmic symptoms but since the disease has other systemic associations, a complete systemic workup should be done to monitor recurrence.

Orbital histiocytosis and fibrohistiocytosis: the clinicopathological characteristics of 117 patients, over a decade of experience

PURPOSE

To describe the clinicopathological features of a large cohort of patients with orbital histiocytoses and fibrohistiocytosis, such as Langerhans cell histiocytosis (LCH) and non-LCH disorders, and correlate patients' clinical characteristics with their pathological diagnosis.

METHODS

In this retrospective study, medical records of patients presenting to Farabi Eye Hospital, a tertiary eye care center in Tehran, Iran, from 2010 until 2022, were reviewed. Patients' demographics, chief complaint, location and laterality of the tumor, best-corrected visual acuity, presence of bone erosion on imaging, and their pathological diagnosis were retrieved. Excisional biopsy was performed and evaluated through light microscopy and immunohistochemistry study for their respective markers, including CD1a, CD68, CD207, and S100.

RESULTS

A total of 117 patients with 11 pathological subtypes of histiocytoses and fibrohistiocyosis were identified, with 56.4% male and 43.6% female patients. The mean age at presentation was 23.4 years (range 1.5 months-73 years). Swelling and palpable mass were the most common chief complaints. LCH was the most common pathology (32.5%), followed by juvenile xanthogranuloma (26.5%) and adult xanthogranuloma (21.4%). Age, lesion location, and bone erosion had a statistically significant difference among the various diagnosed subtypes.

CONCLUSIONS

Histiocytoses and fibrohistiocytosis are diverse and rare disorders potentially involving multiple organ systems. Ophthalmic manifestations of these diseases are even more uncommon. We reviewed their orbital presentation along with their respective histopathological findings. Our results also suggested that an orbital CT scan can be of diagnostic value to discriminate LCH from other histiocytic pathologies.

Hints to Diagnose Intracranial Rosai-Dorfman Disease: A Case Report and Literature Review of Cases in Saudi Arabia

Rosai-Dorfman disease (RDD) was recognized as a distinct clinical entity by Rosai and Dorfman in 1969. It is a rare histiocytic proliferative disorder that occurs in various locations and occasionally involves the central nervous system. In this article, we aim to describe a case of intracranial RDD and to provide a review of the literature on intracranial RDD in Saudi Arabia. A 37-year-old woman presented with a history of generalized seizures. Physical examination disclosed bilateral cervical lymphadenopathy with no neurological deficit. Brain magnetic resonance imaging (MRI) demonstrated an extra-axial, homogenous, Gadolinium-enhancing, space-occupying lesion with extensive dural involvement. The patient was successfully treated by total surgical resection. Postoperatively, the patient did not receive any adjuvant therapy. Biopsy with immunohistochemical analysis confirmed the diagnosis of intracranial RDD. On follow-up examination, six months later, there was no recurrence of the lesion. A preoperative diagnosis of intracranial RDD is challenging since its MRI appearance can be similar to other intracranial diseases. Herein, we discussed some neuroradiographic findings that might help distinguish RDD from other intracranial diseases.

Loss of function of ENT3 drives histiocytosis and inflammation through TLR-MAPK signaling

Histiocytoses are inflammatory myeloid neoplasms often driven by somatic activating mutations in mitogen-activated protein kinase (MAPK) cascade genes. H syndrome is an inflammatory genetic disorder caused by germ line loss-of-function mutations in SLC29A3, encoding the lysosomal equilibrative nucleoside transporter 3 (ENT3). Patients with H syndrome are predisposed to develop histiocytosis, yet the mechanism is unclear. Here, through phenotypic, molecular, and functional analysis of primary cells from a cohort of patients with H syndrome, we reveal the molecular pathway leading to histiocytosis and inflammation in this genetic disorder. We show that loss of function of ENT3 activates nucleoside-sensing toll-like receptors (TLR) and downstream MAPK signaling, inducing cytokine secretion and inflammation. Importantly, MEK inhibitor therapy led to resolution of histiocytosis and inflammation in a patient with H syndrome. These results demonstrate a yet-unrecognized link between a defect in a lysosomal transporter and pathological activation of MAPK signaling, establishing a novel pathway leading to histiocytosis and inflammation.

Tazemetostat for tumors harboring SMARCB1/SMARCA4 or EZH2 alterations: results from NCI-COG pediatric MATCH APEC1621C

BACKGROUND

National Cancer Institute-Children's Oncology Group Pediatric Molecular Analysis for Therapy Choice assigns patients aged 1-21 years with refractory solid tumors, brain tumors, lymphomas, and histiocytic disorders to phase II trials of molecularly targeted therapies based on detection of predefined genetic alterations. Patients whose tumors harbored EZH2 mutations or loss of SMARCB1 or SMARCA4 by immunohistochemistry were treated with EZH2 inhibitor tazemetostat.

METHODS

Patients received tazemetostat for 28-day cycles until disease progression or intolerable toxicity (max 26 cycles). The primary endpoint was objective response rate; secondary endpoints included progression-free survival and tolerability of tazemetostat.

RESULTS

Twenty patients (median age = 5 years) enrolled, all evaluable for response and toxicities. The most frequent diagnoses were atypical teratoid rhabdoid tumor (n = 8) and malignant rhabdoid tumor (n = 4). Actionable alterations consisted of SMARCB1 loss (n = 16), EZH2 mutation (n = 3), and SMARCA4 loss (n = 1). One objective response was observed in a patient with non-Langerhans cell histiocytosis with SMARCA4 loss (26 cycles, 1200 mg/m2/dose twice daily). Four patients with SMARCB1 loss had a best response of stable disease: epithelioid sarcoma (n = 2), atypical teratoid rhabdoid tumor (n = 1), and renal medullary carcinoma (n = 1). Six-month progression-free survival was 35% (95% confidence interval [CI] = 15.7% to 55.2%) and 6-month overall survival was 45% (95% CI = 23.1% to 64.7%). Treatment-related adverse events were consistent with prior tazemetostat reports.

CONCLUSIONS

Although tazemetostat did not meet its primary efficacy endpoint in this population of refractory pediatric tumors (objective response rate = 5%, 90% CI = 1% to 20%), 25% of patients with multiple histologic diagnoses experienced prolonged stable disease of 6 months and over (range = 9-26 cycles), suggesting a potential effect of tazemetostat on disease stabilization.

BRAF testing modalities in histiocytic disorders: Comparative analysis and proposed testing algorithm

OBJECTIVES

Understanding of histiocytic disorders has been revolutionized by demonstration of mitogen-activated protein kinase (MAPK) pathway mutations, most commonly BRAFV600E. The optimal testing strategy to assess BRAFV600E is unknown. We aimed to compare performance of testing modalities, to propose a framework for evaluation of BRAFV600E mutation status in histiocytic disorders.

METHODS

We retrospectively reviewed patients with histiocytic disorders and BRAF mutation testing on a lesional tissue specimen.

RESULTS

In 120 patients, BRAF assessment included immunohistochemistry (IHC) in 97 (80.2%), polymerase chain reaction (PCR) in 35 (28.9%), and next-generation sequencing (NGS) in 62 (51.2%). Forty-five underwent both NGS and IHC. With NGS as the gold standard, the sensitivity and specificity of IHC were 82.4% and 96.4%. Three false negatives were observed in biopsy specimens with low BRAFV600E variant allele frequency or decalcified tissue. One false-positive IHC was observed in a lung biopsy specimen, likely due to antibody cross-reactivity with respiratory cilia. Among 14 with successful NGS and PCR, a single discordance was observed. Two PCR-to-IHC discrepancies were observed, including one other false-positive IHC.

CONCLUSIONS

Immunohistochemistry was highly specific for detection of BRAFV600E. Main caveats were false negatives and lack of detection of non-BRAFV600E mutations. We propose the use of IHC as initial screening in general practice with reflex molecular testing if negative.

Facial Cutaneous Rosai-Dorfman Disease: Dermoscopic Findings with Successful Surgical Treatment

Rosai-Dorfman disease (RDD) is a rare non-Langerhans cell histiocytosis characterized by an accumulation of activated histiocytes within the affected tissues. It is a heterogeneous disease that includes the classical (nodal) and extra-nodal variants. The cutaneous form of the disease without the characteristic lymphadenopathy is rare and is often misdiagnosed as other dermatologic diseases. Misdiagnosis as lymphoproliferative and infectious diseases such as lymphoma and tuberculosis have been reported in the literature. Herein, we report a case of facial cutaneous RDD with successful surgical treatment. In addition, we provide dermoscopic findings and literature review as dermoscopy can be a useful adjuvant tool in the diagnosis of cutaneous RDD.

The changing landscape of pediatric histiocytoses: Birth, life, and transdifferentiation of pediatric histiocytes

Histiocytic neoplasms in the children are very rare, and histiocytoses can occur in the perinatal period. The presumed origins and presentation of specific histiocytoses in the pediatric age group are described. Common and newly described histiocytoses are presented including Langerhans cell histiocytosis, Rosai-Dorfman disease, histiocytic sarcoma, ALK positive histiocytosis, and hemophagocytic lymphohistiocytosis. Molecular findings common to pediatric histiocytoses are also discussed.

Rosai-Dorfman disease of the breast: a clinicoradiologic and pathologic study

Rosai-Dorfman disease (RDD) is an uncommon histiocytic disorder typically involving lymph nodes and less frequently extranodal tissues. RDD involving the breast is rare and may clinically and radiologically mimic neoplastic and non-neoplastic disorders. We report seven patients with breast RDD, describe their clinicoradiologic and pathologic features, and discuss the differential diagnosis. Patients, ranging from 15 to 74 years of age, presented with unilateral and unifocal (5/7) or bilateral and multifocal (2/7) masses. RDD was either confined to the breast (6/7) or concurrently involved a lymph node (1/7). Masses ranged from 8 to 31 mm, categorized as Breast Imaging-Reporting and Data System (BI-RADS) 4 (6/7) or 5 (1/7). All cases showed similar morphology with many large histiocytes displaying emperipolesis with associated fibrosis and dense lymphoplasmacytic infiltrate. The abnormal histiocytes co-expressed CD68/CD163, S100, OCT2, and Cyclin D1 (7/7), and were negative for CK AE1/AE3 (7/7), CD1a (7/7), and BRAF V600E (6/6). Flow cytometry (n = 3), kappa/lambda in situ hybridization (n = 5), and IgG4/IgG immunohistochemistry (n = 1) did not reveal lymphoma or IgG4-related disease. No mycobacterial or fungal organisms were identified on acid-fast bacillus (AFB) and Grocott methenamine silver (GMS) stains (n = 5). Three patients underwent complete excision and none recurred or progressed to systemic disease during follow-up (88-151 months). In summary, breast RDD should be included in the differential diagnosis of a mass-forming breast lesion. Histopathology with ancillary studies and clinicoradiologic correlation is essential for accurate diagnosis and optimal clinical management. Patients with RDD of the breast have an excellent prognosis after complete excision.

Cervical spine Rosai-Dorfman disease: A case report and literature review

BACKGROUND

Rosai-Dorfman disease is a benign lymphatic tissue proliferative disease with slow growth and is rarely observed in the clinic. Most of these patients present clinically with enlarged lymph nodes. In patients with spinal extranodal Rosai-Dorfman disease, which is even rare than the disease of lymph nodes, patients may experience numbness and weakness in the extremities.

CASE PRESENTATION

We report a 32-year-old male patient with multi-segmental spinal Rosai-Dorfman disease. On admission, his left fingers had been numb for 2 months. Over a 2-month period, the limb numbness progressed from the left to the right hand. The patient underwent resection of the lesion and internal fixation of the C2-C7 spine. The postoperative outcomes were satisfied and no recurrence was observed at 1-year follow-up.

CONCLUSION

Spinal Rosai-Dorfman disease is a relatively rare tumor of which the pathogenesis is still unclear, and most patients have no specific clinical manifestations. Characteristic imaging findings can indicate this disease, however, a definitive diagnosis still depends on a pathological examination. Currently, total surgical resection of the tumor is a relatively effective and preferred treatment.

Erdheim-Chester Disease Due to a Novel Internal Duplication of NRAS: Response to Targeted Therapy with Cobimetinib

Histiocytoses encompass a group of exceptionally rare disorders characterized by the abnormal infiltration of tissues by histocytes. Among these, Erdheim-Chester disease (ECD) stands out as a multisystem histiocytosis that typically affects bones and various other tissues. Historically, the treatment of ECD has been challenging. However, recent breakthroughs in our understanding, particularly the discovery of somatic mutations in the RAS-MAPK pathway, have opened new opportunities for targeted therapy in a significant subset of patients with ECD and other histiocytoses. In this report, we present the case of a patient with ECD harboring a previously unidentified microduplication in the NRAS gene in a small fraction of skin cells. This discovery played a pivotal role in tailoring an effective therapeutic approach involving kinase inhibitors downstream of NRAS. This case underscores the crucial role of deep sequencing of tissue samples in ECD, enabling the delivery of personalized targeted therapy to patients.

Letter to the Editor: "Rosai Dorfman: Rare Cause of Cervical Lymphadenopathy"

We read with great interest the article by Kobayashi KE et al. published in 2023 entitled: "Presentation of external ear Rosai-Dorfman disease with laryngeal involvement" and wish to reconnoiter Rosai-Dorfman Disease's (RDD) clinical entities and the possible implications from the perspective of otology.

Primary unifocal thymic Rosai-Dorfman disease: an extremely rare challenge in diagnostic practice

Rosai-Dorfman disease (RDD) is currently considered a group of neoplastic diseases of unknown etiology, with monoclonal proliferation of histiocytes, showing unique histopathologic features and varying clinical presentation. Primary thymic RDD is an extremely rare extranodal form of this disorder. In this study, we describe the case of an otherwise healthy 64-year-old Chinese man who presented with an isolated, asymptomatic soft tissue density lesion in the anterior mediastinum detected by computed tomography. Histology of the surgical specimen revealed infiltration of thymic tissue by sheets of large histiocytes with mixed lymphocytes and plasma cells, and background fibrosis. Immunohistochemical staining of the histiocytes was positive for S100, CD68, CD163, OCT2 and cyclin D1, but negative for CD1a and BrafV600E expression, thus supporting a diagnosis of RDD. Primary thymic RDD is extremely rare and may be a diagnostic challenge when presenting as mediastinal lesion.

Primary Bilateral Intraosseous Rosai-Dorfman Disease

Rosai-Dorfman disease (RDD) is a rare histiocytic proliferative disease of unknown etiology. Typically presenting with cervical adenopathy and constitutional symptoms, RDD involves bone in less than 10% of cases-and rarely presents as a primary intraosseous lesion. In this report, we describe the presentation of primary, bilateral intraosseous RDD, the first known case in the literature. Asymmetrically involving the lateral femoral condyles of a 59-year-old male, the lesion was discovered incidentally during evaluation and workup for giant cell tumor of bone involving the left tibia. Confirmation of the diagnosis required multiple biopsies and extensive evaluation-reflecting the diagnostic challenge associated with this case. We discuss the clinical, radiological, and pathological findings that allowed us to establish the diagnosis-as well as key differential diagnostic considerations and clinical outcome to date.

Impact of BRAFV600E mutation on aggressiveness and outcomes in adult clonal histiocytosis

Histiocytoses encompass a wide spectrum of diseases, all characterized by tissue infiltration by CD68+ histiocytes. Most adult histiocytoses are considered clonal diseases because they highlight recurrent somatic mutations in the MAP-kinase pathway gene, primarily BRAF. The presence of BRAF mutation is associated with widespread disease in children with Langerhans cell histiocytosis (LCH) or cardiovascular/neurological involvement in Erdheim-Chester disease (ECD). Nevertheless, few data are available on adult clonal histiocytosis. This is why we have conducted a retrospective study of all patients with clonal histiocytosis in our institution and present the data according to the presence of BRAF mutation. Among 27 adult patients (10 ECD, 10 LCH, 5 Rosai-Dorfman disease (RDD), and 3 mixed ECD/LCH), 11 (39%) have BRAF mutation with gain of function (n = 9) and deletion (n = 2). Those patients had frequent multicentric disease with risk organ involvement, especially the brain and cardiovascular system. They had frequent associated myeloid neoplasms (mostly chronic myelomonocytic leukemia) and received more frequently targeted therapy as the front-line therapy. Nevertheless, its presence did not affect the overall survival or relapse-free survival probably due to the emergence of efficient therapies. To conclude, rapid and accurate molecular establishment in adult clonal histiocytoses is crucial because BRAFV600E mutation correlates with multicentric disease with organ involvement and incomplete metabolic response.

Rosai-Dorfman Disease of Nasal Soft Tissue: A Case Report

Rosai-Dorfman disease (RDD) is characterized by sinus histiocytosis with massive lymphadenopathy, and the tissue exhibits positive results for S100 and CD68. This lesion typically affects the lymph nodes and rarely involves the nasal soft tissues. This report aims to present a case of RDD involving the nasal soft tissues, presenting with nasal congestion and rhinorrhea as the primary complaints. The patient underwent surgery navigated by nasal endoscope did not report recurrence after operation.

Coexistence of Rosai-Dorfman disease and Hodgkin's lymphoma in a patient with cervical lymphadenopathy

A man in his 40s, with no tobacco or alcohol habit, was referred to the otorhinolaryngology department presenting with a 2-month history of enlarged left cervical lymphadenopathy with no other signs or symptoms. The ear, nose and throat examination showed no abnormalities apart from the described lymphadenopathy. An ultrasound scan suggested these nodes to be part of either an inflammatory or a malignant process. Subsequent positron emission tomography-CT proved those lymph nodes to be metabolically active, as well as others within the thorax. Cervicotomy was performed and the histopathological analysis showed dilated sinuses and histiocytes with emperipolesis. Suspecting Rosai-Dorfman disease (RDD), high-dose steroid therapy was started; but given no improvement was observed, a second cervicotomy was performed, with the histopathological diagnosis of the latter of Hodgkin's lymphoma. The present article aims to emphasise the need to exclude haematological disorders whenever RDD histology is observed, given their possible coexistence, and a worse outcome and clinical and histopathological semblance.

Rosai-Dorfman Disease in a Pediatric Patient: Imaging Findings and Pathology with a brief review of the Literature

Rosai-Dorfman Disease, otherwise known as sinus histiocytosis with massive lymphadenopathy, is a rare form of non-Langerhans cell histiocytosis with an estimated incidence of 100 cases per year in the United States. Due to its variable presentation and nonspecific clinical findings, it is particularly difficult to diagnose in pediatric patients. We report a case of an 11-month-old male who presented with a 4-day history of a right groin mass. Ultrasound of the groin and pelvis demonstrated, and MRI of the abdomen and pelvis confirmed an inguinal mass with surrounding lymphadenopathy. Pathology confirmed Rosai-Dorfman Disease and the patient improved after starting oral steroid therapy. To the best of our knowledge, this is the first case of Rosai-Dorfman Disease involving the inguinal region in an infant under 1 year of age reported in the literature. In this case report, we discuss the imaging and histology findings as well as provide a brief literature review for this diagnosis.

Rosai-Dorfman-Destombes Disease in the Pediatric Head and Neck

BACKGROUND

Rosai-Dorfman-Destombes disease (RDD), or sinus histiocytosis with massive lymphadenopathy, is a rare form of non-Langerhans cells histiocytosis. It has a wide-ranging variability in presentation since first described in 1969 but much of its characteristics in children remain unknown.

METHODS

A retrospective chart review of children diagnosed with RDD at a tertiary care children's hospital was conducted from 2000 to 2021.

RESULTS

Twelve RDD patients were identified, with an average age of 7 years (SD 4.3). Males comprised 58% of the cohort, and African American ethnicity was most common (42%). Nodal RDD was found in 7 patients (58%). Nine patients (75%) presented RDD within the head and neck, 6 of whom had nodal RDD. The most common presentation was cervical lymphadenopathy, which most often involved levels V (67%), II (56%), III (44%), and I (11%), in order of frequency. Recurrence and persistence of disease after initial treatment was common, with 5 (42%) being disease free at the time of the last follow up. Fifty-eight percent (7/12) developed recurrence or had persistent disease and 4 required adjuvant systemic treatment with corticosteroids and/or chemotherapy. One patient succumbed after developing treatment related acute myelodysplastic leukemia (t-AML) from chemotherapy used to treat recurrent RDD.

CONCLUSION

Pediatric RDD presents at a young age and most commonly involving cervical lymphadenopathy. Ongoing surveillance in the setting of persistence or recurrence without clearly defined prognostic risk factors is important.

Characterizing Rosai-Dorfman disease with [18F]FDG PET/CT: a retrospective analysis of a single-center study

OBJECTIVES

Rosai-Dorfman disease (RDD) is a rare non-Langerhans cell histiocytic proliferative disorder. We performed a retrospective study to characterize the clinical and [18F]FDG PET/CT features of RDD.

METHODS

We retrospectively recruited 38 RDD patients with [18F]FDG PET/CT scan in our center. [18F]FDG PET/CT features were assessed, and clinical and follow-up data were recorded.

RESULTS

In the recruited patients, 20/38 (52.6%) patients had single-system disease, while others (18/38, 47.4%) had disease affecting multiple system. RDD most commonly involved the upper respiratory tract (47.4%), followed by cutaneous/subcutaneous lesion (39.5%), lymph node (36.8%), bone (31.6%), central nervous system (28.9%), and cardiovascular system (13.2%) in the recruited patients. In PET/CT, the RDD lesions were FDG-avid, and the SUVmax of the hottest lesion in an individual patient was positively correlated with C-reactive protein levels (r = 0.418, p = 0.014), and negatively correlated with hemoglobin levels (r =  -0.359, p = 0.036). The overall response rate of the first-line treatment was 80.8% in newly diagnosed RDD patients, and for patients with relapsed/progressive RDD, the overall response rate was 72.7%.

CONCLUSION

[18F]FDG PET/CT could be a useful tool for evaluating RDD.

KEY POINTS

• About half of the patients with Rosai-Dorfman disease had single-system disease, while others had disease affecting multiple system. Rosai-Dorfman disease most commonly involved the upper respiratory tract, followed by cutaneous/subcutaneous lesion, lymph node, bone, central nervous system, and cardiovascular system. • In [18F]FDG PET/CT, Rosai-Dorfman disease was usually hypermetabolic, and the SUVmax of the hottest lesion in an individual patient was positively correlated with C-reactive protein levels. • Rosai-Dorfman disease usually has a high overall response rate after treatment.

[Histiocytosis]

Histiocytosis is a group of rare diseases characterized by inflammation and accumulation of cells derived from monocytes and macrophages in different tissues. The symptoms are highly variable, from mild forms with involvement of a single organ to severe multisystem forms that can be life compromising. The diagnosis of histiocytosis is based on the clinic, radiological findings and pathological anatomy. A biopsy of the affected tissue is recommended in all cases as it may have therapeutic implications. During the last decade, some mutations have been identified in the affected tissue that condition activation of the MAPK/ERK and PI3K/AKT pathway, in a variable proportion depending on the type of histiocytosis. In this review we mainly focus on Langerhans Cell Histiocytosis, Erdheim-Chester Disease and Rosai-Dorfman Disease.

Mammary Rosai-Dorfman disease: Rare benign mimic of breast malignant neoplasm

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.

Anesthetic Management for a Patient with Rosai-Dorfman Disease, Cowden Syndrome, and Lhermitte-Duclos Disease: An Extremely Rare Disease Combination

Rosai-Dorfman disease (RDD) is a rare condition that causes massive lymphadenopathy, most commonly in the cervical area. Cowden syndrome (CS) causes hamartomas in the skin and mucosa and predisposes individuals to various malignancies. Lhermitte-Duclos disease (LDD), or dysplastic cerebellar gangliocytoma, is often associated with CS. A 41-year-old female with all three conditions presented with abnormal uterine bleeding and endometrial intraepithelial neoplasia (EIN). Precautions should be considered when evaluating patients with RDD and CS preoperatively and during airway management owing to the potential for multisystem involvement, anatomical distortion, and difficult airways. The likelihood of having all three conditions is extremely rare.

Successful anesthesia management with inhalation anesthesia in Rosai-Dorfman disease: a case report

Rosai-Dorfman disease (RDD) is a rare, benign, non-Langerhans cell histiocytic proliferative disease. RDD with central nervous system involvement is extremely rare. Surgical excision is generally regarded as the appropriate treatment of choice for this disease, especially when the lesion causes neurological compression. RDD can be accompanied by systemic symptoms, such as malaise, fever, weight change, leukocytosis, anemia, and hormonal disturbance, which may be challenging during general management. Little is known regarding peri-anesthesia management of this rare disease. We report a case of a patient in his 20s who had recurrent RDD and had general anesthesia with perioperative management. He was obese and hepatic insufficiency. This case report adds to the literature regarding the perioperative anesthetic management of RDD with central nervous system involvement.

A meta-analysis of cases of Rosai Dorfman disease reported on the African continent and a description of two cases from a tertiary academic hospital in Johannesburg, South Africa

Rosai-Dorfman-Destombes disease (RDD) is a rare non-Langerhans cell histiocytosis characterized by the accumulation of activated histiocytes within affected tissues. The original haematopathological description of RDD has links to the late South African born haematopathologist, Ronald Dorfman, with a descriptive account of two cases of the disease treated at Chris Hani Baragwanath Academic Hospital are described herein. Alongside the two case descriptions is a meta-analysis of 149 published cases from the African continent. Sequential literature searches were performed on Google Scholar and PubMed with the search terms "sinus histiocytosis with massive lymphadenopathy", "Rosai-Dorfman disease", "Rosai-Dorfman Destombes" and "lymphadenopathy" together with the name of each individual country on the African continent, from Algeria to Zimbabwe. All possible cases of RDD reported in published literature from Africa were captured on a Microsoft Excel spreadsheet recording details, where available, of demographics, nodal (nodal groups) or extra-nodal disease as well as treatment. Of the 54 African countries on the continent, published data was available from half of these countries (n=27). Nigeria (35), Tunisia (25) and South Africa (23) contributed the majority of cases for data collection with a clear paucity of reportable information available from Central Africa. Of the 149 cases from the African continent, the majority were from patients aged ten years and younger with a decrease in reported cases in patients with increasing age. The mean age at diagnosis was 25.66 years [95% CI: 21.81-29.51] with a median age of diagnosis of 24.5 years. The youngest patient in the series was 3 months old and the oldest patient aged 72 (range 71.75 years, IQR 31). The cases reported were fairly split between males and females with a male-to-female ratio of 1.07: 1. HIV seropositivity was reported in seven patients (4.8%) and no HIV results were available in 104 patients (71.2%). Disease presentation was split between nodal disease in 43% of patients (n=64), Extra nodal (EN) disease in 32.9% (n=32), mixed (nodal/EN) disease in 11.4% (n=17) and unknown in 12.8% (n=19). Fever was present in 18.1% (n=27) of cases. Hepatic enlargement was noted in nine patients (6%) and splenic enlargement in four patients (2.7%). Commonly ascribed sites of EN disease, in descending order, were skin and soft tissue, ocular, ear/nose/throat (ENT), abdominal organ(s), bone, lung/pleura, brain parenchyma (including dura), endocrine glands, spine, breast, pericardium, pseudotumour formation (unspecified site), joint(s), peripheral nerves and genitourinary tract disease. The upfront administration of glucocorticosteroids was seen in the majority of cases. Rosai-Dorfman-Destombes, although a rare disorder, should be considered as a differential diagnosis in patients with massive bilateral cervical lymphadenopathy and is confirmed with accompanying pathological changes on microscopic and immunohistochemical examination of biopsy specimens. The role of infection, particularly HIV infection, is considered to be a possible contributor to the pathogenesis of RDD and HIV testing in patients from areas of high HIV endemicity with co-existing RDD should be undertaken. Consideration for mycobacterium tuberculosis infection in patients with generalized significant lymphadenopathy still remains an important differential for massive lymphadenopathy and requires confirmation by appropriate microbiological investigations. The treatment landscape in RDD is limited in many resource-poor settings, with the upfront use of glucocorticosteroids employed routinely in the majority of cases.

A Case of Rosai-Dorfman Disease Presenting as an Isolated Pleural Plaque

Rosai-Dorfman disease (RDD) is a rare non-Langerhans histiocytic disorder primarily involving lymph nodes. Extranodal RDD has a heterogenous presentation, and isolated pulmonary involvement is rare. We report the only case of RDD presenting as an isolated pleural mass. Our patient was a 55-year-old female with multiple comorbidities who presented with chest pain. Imaging revealed an enlarging pleural-based lesion. She underwent resection of the pleural mass, showing an atypical histiocytic infiltrate in a prominent background of collagenous fibrosis. Immunohistochemistry shows CD1a-negative and S100-positive atypical histiocytic cells demonstrating emperipolesis, confirming the diagnosis of RDD. She is currently on six-month CT surveillance with no recurrence of the disease. This case highlights the unique pulmonary presentation of RDD. It also underscores that observations may be appropriate in isolated asymptomatic pleural involvement cases.

Rosai-Dorfman Disease of the Rectum: Newly Identified Genetic Point Mutations and Robotic Resection

Rosai-Dorfman disease (RDD) is a rare disease characterized by histiocytic proliferation which typically presents as massive, painless, cervical lymphadenopathy in children or young adults. GI involvement is exceedingly rare with only 20 documented cases to date. Of those 20 cases, only 3 cases have involved the rectum. Here, we present 2 cases of rectal RDD with attention paid to the diagnostic and technical challenges presented by this disease. When presenting as a perirectal mass, RDD can be mistaken for other lesions to include malignancy, leading to surgical removal. We present a video of a robotic low-anterior resection with intracorporeal anastomosis in order to remove a pelvic mass involving the rectum, initially considered to be a stromal tumor. In addition, we describe a copy number variation in AKT and 3 point mutations detected by next generation sequencing, which had not been previously reported in association with this disease.

Imaging diagnostic features of intracranial primary extranodal Rosai-Dorfman disease: Two case reports and literature review

In this report, we describe 2 cases of rare intracranial extranodal Rosai-Dorfman disease. The occurrence of this type of non-Langerhans cell histiocytosis in the central nervous system is infrequent, with less than 5% of cases. The first patient was a 35-year-old male who presented with recurring headaches, and the second patient was a 50-year-old male who reported sudden onset of dizziness and vomiting. Computed tomography scans were performed in both cases, but magnetic resonance imaging played a crucial role in the characterization of the lesions and their locations in the thalamus, third ventricle, lateral ventricles, and cerebellopontine angle area. The final diagnosis was confirmed through pathological examination and immunohistochemistry following brain tumor resection. These cases underscore the significance of magnetic resonance imaging in the early diagnosis of intracranial extranodal Rosai-Dorfman disease.

Synchronous Mediastinal and Central Nervous System Involvement in Rosai-Dorfman Disease: A Case Report

Rosai-Dorfman disease (RDD) is a rare disorder characterized by the proliferation and accumulation of histiocytes, primarily within lymph node sinuses. Uncommonly, other extranodal sites, such as the central nervous system, can also be affected. Here, we document the case of a 61-year-old woman presenting with dizziness, confusion, and headaches. Magnetic resonance imaging (MRI) showed an extra-axial avidly enhancing mass in the left parietal region presumed to be a meningioma based solely on its imaging appearance. The patient underwent surgical resection, and histopathological examination showed enlarged histiocytes positive for S100, CD68, and CD163 and negative for CD1a, consistent with RDD. She was followed up with a positron emission tomography/computed tomography (PET/CT) to evaluate other disease activity sites. A single mediastinal node was identified adjacent to the atriocaval junction intensely fluorodeoxyglucose avid. The patient underwent robotic node excision, with pathology analysis compatible with RDD. We emphasize the need to increase recognition of RDD on differential brain lesions, especially meningiomas, and suggest PET/CT as a valid tool to search for other disease activity lesions.

Sporadic Red Papules on the Face: A Quiz

Abstract is missing (Quiz)

Treatment of Langerhans Cell Histiocytosis and Histiocytic Disorders: A Focus on MAPK Pathway Inhibitors

Histiocytic disorders are rare diseases defined by the clonal accumulation of a macrophage or dendritic cell origin. These disorders include Langerhans cell histiocytosis, Erdheim-Chester disease, juvenile xanthogranuloma, malignant histiocytoses, and Rosai-Dorfman-Destombes disease. These histiocytic disorders are a diverse group of disorders with different presentations, management, and prognosis. This review focuses on these histiocytic disorders and the role of pathological ERK signaling due to somatic mutations in the mitogen--activated protein kinase (MAPK) pathway. Over the last decade, there has been growing awareness of the MAPK pathway being a key driver in many histiocytic disorders, which has led to successful treatment with targeted therapies, in particular, BRAF inhibitors and MEK inhibitors.

Interatrial Septal Mass Secondary to Rosai-Dorfman Disease: A Rare Cause of Complete Heart Block

Varying degrees of atrioventricular block can be associated with old age or a manifestation of an ischemic, metabolic, or infective pathology. In patients with no clear explanation, it is important to investigate secondary causes. Our case describes the first case of an adult with Rosai-Dorfman histiocytosis presenting with complete heart block. (Level of Difficulty: Advanced.).

The value of 18F-FDG PET/CT in the systemic evaluation of patients with Rosai-Dorfman disease: a retrospective study and literature review

BACKGROUND

Rosai-Dorfman disease (RDD) is a rare form of non-Langerhans cell histiocytic disease. The aim of this study was to review the characteristics of RDD using ¹⁸F-FDG PET/CT and determine its efficacy in the disease management.

RESULTS

A total of 28 RDD patients underwent 33 ¹⁸F-FDG PET/CT scans for systematic assessment and follow-up. The common involved sites included the lymph nodes (17, 60.7%), upper respiratory tract (11, 39.3%), and skin (9, 32.1%). Five patients had more lesions detected in PET/CT images than in CT and/or MRI, including inapparent nodules (n = 5) and bone destruction (n = 3). After thorough treatment evaluation using PET/CT, the treatment strategies of 14 patients (14/16, 87.5%) were changed. Five patients underwent PET/CT twice during follow-up and the SUVs were significantly decreased (15.3 ± 3.4 vs. 4.4 ± 1.0, p = 0.02), which demonstrated disease improvement.

CONCLUSIONS

¹⁸F-FDG PET/CT contributed to displaying the holistic characteristics of RDD, in particular during initial assessment, treatment strategy adjustment, or efficacy evaluation, and could compensate for some disadvantages of CT and MRI images.

How I Diagnose Rosai-Dorfman Disease

OBJECTIVES

Rosai-Dorfman disease (RDD) is one of 3 major types of histiocytosis, along with Erdheim-Chester disease and Langerhans cell histiocytosis. While historically, RDD was considered a benign self-limited condition, current data show MAPK/ERK pathway mutations in 30% to 50% of cases, indicative of a clonal process. Rosai-Dorfman disease was incorporated as a histiocytic neoplasm in the fifth edition of the World Health Organization classification of hematopoietic tumors and the International Consensus Classification.

METHODS

We discuss the diagnosis of RDD using 2 illustrative cases, interpretative challenges, and a diagnostic algorithm.

RESULTS

Rosai-Dorfman disease involves nodal and extranodal sites, including skin, sinuses, salivary gland, orbit, central nervous system, kidney, and bone. In a subset, RDD can coexist with other neoplasms (lymphomas, other histiocytosis) or autoimmune disease. Morphologically, RDD histiocytes are characterized by enlarged round to oval nuclei, distinct nucleoli, and voluminous cytoplasm with engulfment of inflammatory cells (emperipolesis). By immunohistochemistry, they express CD68, CD163 (majority), S100, OCT2, and cyclin D1. Appropriate use of ancillary studies is important to support the diagnosis of RDD while excluding other histiocytic neoplasms and reactive histiocytic proliferations.

CONCLUSIONS

Management of RDD is dependent on the extent of organ involvement and clinical symptoms. In patients who require therapy, next-generation sequencing is recommended to identify MAPK/ERK pathway mutations for targeted therapy.

A Rare Cause of Lymphadenopathy in a Young Hispanic Female: Unmasking Recurrent Nodal Rosai-Dorfman Disease

Rosai-Dorfman disease (RDD) is a rare histiocytic disorder that can present with painless bilateral symmetrical cervical lymphadenopathy, mimicking lymphomas. RDD is characterized by excessive tissue infiltration by dendritic cells, macrophages, or monocyte-derived cells, with a histopathologic diagnosis based on the presence of CD68+, CD163+, and S100+ histiocytes, which differentiate it from other histiocytic neoplasms. In this case report, we present a young Hispanic female with recurrent subcutaneous growths and lymphadenopathy, initially thought to be lymphoma, who was diagnosed with RDD after a significant diagnostic workup. Treatment initially consisted of surgical excision; however, due to recurrence, the patient was successfully treated with corticosteroids and a steroid-sparing agent, 6-mercaptopurine, with significant improvement in symptoms. RDD should be considered a differential diagnosis for patients with cervical lymphadenopathy, and an interdisciplinary approach is essential to managing this rare disorder effectively. The report highlights the need for an interdisciplinary approach to managing this rare disorder effectively and underscores the importance of multimodal treatment in disease suppression. As a rare disease with slow advancement of defined guidelines for diagnostic and treatment strategies, this case report adds to the existing literature on RDD.

Immunoglobulin G4-Associated Rosai-Dorfman Disease: Report of 3 Cases

Rosai-Dorfman disease is characterized by dilated lymph node sinuses filled with lymphocytes, plasma cells, and histiocytes. Many of these histiocytes classically exhibit emperipolesis of lymphocytes and plasma cells. Abundant immunoglobulin G4+ plasma cells occur in some cases, and a potential relationship with immunoglobulin G4-related disease has been suggested. Here, we report 3 cases of immunoglobulin G4-associated Rosai-Dorfman disease. Immunoglobulin G4-related disease was suspected based on immunoglobulin G4+ plasma cell infiltration, but the final diagnosis was immunoglobulin G4-associated Rosai-Dorfman disease. At present, the evidence does not support a link between immunoglobulin G4-associated Rosai-Dorfman disease and immunoglobulin G4-related disease, and one condition should not be considered part of the spectrum of the other. We believe it is of paramount importance to increase the awareness of immunoglobulin G4-associated Rosai-Dorfman disease for pathologists who interpret the biopsies and clinicians who integrate the diagnosis and treat such patients to not overdiagnose immunoglobulin G4-related disease.

A rare case of Rosai-Dorfman disease presenting as a pulmonary artery mass in a 33-year-old female with hypoxia

Rosai-Dorfman disease (RDD) is a rare form of non-Langerhans histiocytosis. It is often idiopathic in etiology, but has been associated with viral, autoimmune, and malignant disease. Adequate diagnosis of RDD requires a combination of clinical symptoms, radiography, and histology. Most commonly, patients with RDD present with cervical lymphadenopathy. We describe a case of a young female who was initially thought to have a pulmonary embolism at the time of a COVID-19 infection but was noted to have a rare occurrence of RDD presenting as a pulmonary artery mass upon further evaluation of radiology and histology. Though RDD is frequently benign, extranodal involvement can progress to end organ damage and must be recognized appropriately.

[Cervical tumefaction in a child at Brazzaville University Hospital, Republic of the Congo]

A 8-year-old schoolgirl from West Africa with no previous pathological history was admitted to the haematology department of the Brazzaville University Hospital for the management of cervical adenopathy. The diagnosis of sinus histiocytosis or Destombes-Rosaï-Dorfman disease was retained and the patient was treated with PO corticosteroids (methylprednisolone 32 mg/d then 16 mg/d). Given the rarity and uncertain aetiopathogeny of this syndrome, treatment is poorly codified. It includes corticosteroid therapy, immunomodulators and sometimes chemotherapy, radiotherapy or surgery, indicated in case of clinical manifestations of local organ compression. The disease may regress spontaneously. Its benignity does not justify systematic treatment in the absence of complications.

Nasal Presentations of Rosai-Dorfman Disease: Clinical Manifestation and Treatment Outcomes

PURPOSE

There has been a lack of evidence-based management strategies on the nasal presentations of Rosai-Dorfman disease (RDD). We aim to investigate the clinical manifestation, treatment, and outcomes in patients with nasal RDD.

METHODS

We retrospectively reviewed available medical records of patients diagnosed with nasal RDD from 2014 to 2021 at our department.

RESULTS

A total of 26 patients were included with a marked female preponderance (2.25:1). The most common symptom and affected sites were nasal congestion (31%) and nasal cavity (73%), respectively. The average times of biopsies was 1.5 times (range: 1-3). The histiocytes were positive about S100 and CD68 and negative for CD1a with common emperipolesis. The mean duration of follow-up was 34 months (range, 3-87). One patient with concomitant nasal small B-cell lymphoma achieved complete remission after chemoradiotherapy. Recommended treatments were endoscopic resection (92%) and oral corticosteroids (21%). Surgery was performed to remove the resectable lesion as completely as possible. Corticosteroids induced almost 100% overall remission. Of the relapses, two patients achieved an overall response and one remained in progressive stage after subsequent excision. Two patients only received dissection biopsy that responded to oral corticosteroid administration and combined therapies of lenalidomide and dexamethasone, respectively.

CONCLUSIONS

Diffuse lesions in nasal cavity and sinuses, and even widely affected nasal skull base, laryngopharynx, orbit, and cavernous sinus, should be considered the possibility of Rosai-Dorfman disease. Characteristic immunohistochemical staining is helpful for the diagnosis. Endoscopic surgical therapy remains the mainstream treatment for patients enduring an unbearable course. Oral corticosteroid administration serves as an adjuvant therapy for first-line treatments.

Rosai-Dorfman: Rare Manifestations of a Rare Disease

Rosai-Dorfman disease (RDD) is an exceedingly rare non-Langerhans cell histiocytosis of uncertain etiology that most commonly presents in children as self-limited, painless, massive cervical lymphadenopathy. However, extranodal disease occurs in 43% of cases and has a wide range of phenotypic presentations. The pathogenesis has not been clearly understood in the literature and coupled with a wide range of clinical manifestations, early diagnosis and initiation of an appropriate treatment modality have been challenging. Herein, we describe a cohort of five cases that occurred at the same institution within a 12-month period. These cases highlight unique and atypical presentations of an already rare disease, outline the varying and tailored diagnostic and therapeutic approaches, and propose a novel environmental predisposing factor given the exceptionally high incidence at our institution over a short period of time. We emphasize the need for further investigation of predisposing factors and to discern targeted therapies that may offer benefits.

Asymptomatic Rosai-Dorfman-Destombes disease presenting as isolated bilateral perinephric infiltration: a case report and review of the literature

Background

Rosai-Dorfman-Destombes disease (RDD) is a rare histioproliferative disease with unknown etiology. It commonly occurs in lymph nodes and can affect extra-nodal tissues and organs. Renal RDD is extremely rare, only a few cases have been reported, and its clinical symptoms and imaging findings are non-specific. To date, no literature has summarized its imaging manifestations in a large number of cases. Due to the involvement of different tissues and organs, there is no standard treatment for RDD. It has been reported that RDD patients with kidney involvement have a poor prognosis. Thus, understanding of renal RDD need to be extended.

Case Description

We present a rare case of renal RDD in an asymptomatic 67-year-old male. The results of an ultrasound examination indicated that both kidneys were surrounded by hypoechoic soft tissue lesions, and there was a huge mass in the left kidney, which had a clear boundary with the renal capsule. The results of contrast-enhanced ultrasound (CEUS) showed hypo-enhancement in the bilateral perinephric lesions and mass. However, the computed tomography urography (CTU) findings revealed no obvious enhancement. The patient then underwent a series of laboratory tests, but no relevant information was found. To make a clear diagnosis, the urologist then removed the left perirenal mass and some perirenal tissues, and the patient was finally pathologically diagnosed with extra-nodal RDD. The patient remains asymptomatic, and no treatment has been administered to date.

Conclusions

This case may be the first reported case in which CEUS was performed and the second reported case of asymptomatic renal RDD. Based on the previous literature reports, we found that some specific characteristics of renal RDD include bilateral perirenal lesions with a "hairy kidney" appearance. CEUS and/or CTU can be used to help differentiate a solitary mass of RDD from common tumors, to avoid misdiagnosis leading to unnecessary nephrectomy.