Mediastinal Rosai-Dorfman Disease with KRAS mutation case report and literature review.

BACKGROUND: Rosai-Dorfman Disease (RDD) is a rare self-limiting histiocytosis, more prevalent in children and young adults. It typically manifests as painless bilateral massive cervical lymphadenopathy but may also extend to extra-nodal sites, with intrathoracic RDD noted in 2% of cases. Distinguishing mediastinal RDD from thymoma on imaging poses challenges, underscoring the reliance on pathological features and immunohistochemical staining for diagnosis. CASE PRESENTATION: Patient, male, 33 years old, underwent lung a CT revealing an enlarged round soft tissue shadow in the anterior superior mediastinum, compared to a year ago. Surgical resection removed the entire mass, thymus, and part of the pericardium, confirming RDD on pathology. Genetic testing using second-generation testing technology identified a KRAS gene point mutation. CONCLUSIONS: No established treatment protocol currently exists for this disease. However, as genetic mutation research progresses, a novel therapeutic avenue is emerging: targeted therapy integrated with surgical interventions.

Rosai-Dorfman disease manifesting as a solitary mass with fat in the thymus a case report.

BACKGROUND: Sinus histiocytosis with massive lymphadenopathy, also known as Rosai-Dorfman disease, is a rare, self-limiting disease that predominantly affects children and young adults. Moreover, the disease is characterized by painless bilateral cervical lymphadenopathy in 95% of the patients. However, few reports are available on the Rosai-Dorfman disease of the thymus. CASE PRESENTATION: We report a rare case of thymic Rosai-Dorfman disease detected using computed tomography. During a medical examination, a 50-year-old man underwent a chest computed tomography scan, which revealed an anterior mediastinal single mass with fat in the thymus. A thymectomy was performed to completely remove the tumor using a thoracoscopic technique due to a clinical suspicion of thymoma. Furthermore, Rosai-Dorfman disease was confirmed using histological and immunohistochemical analyses. CONCLUSIONS: To the best of our knowledge, this is the sixth case of thymus-affecting solitary Rosai-Dorfman disease with histological and immunohistochemical evidence. Fat in the thymus, as was present in this case, has never been described in Rosai-Dorfman disease previously. Our results highlight the challenge of diagnosing this uncommon tumor before surgery, and more cases need to be reported to help with the preoperative diagnosis of such a rare tumor.

Extranodal Rosai-Dorfman disease manifesting as Sjögren's syndrome combined with panuveitis and hypertrophic pachymeningitis: a case report and review of literature.

Rosai-Dorfman disease (RDD) is a rare non-Langerhans cell histiocytosis characterized by massive lymphadenopathy and systemic extranodal lesions. We present the case of a 28-year-old woman who presented with recurrent blurred vision in her right eye for 3 months. She developed blindness and atrophy in her left eye a decade prior to presentation. She subsequently developed headache, fever, and impaired mental status. Cranial magnetic resonance imaging indicated hypertrophic pachymeningitis (HP), and 18F-fluoro-2-deoxy-2-d-glucose (FDG) positron emission tomography/computed tomography revealed significant FDG uptake in the left dura mater. Autoimmune testing revealed elevated anti-nuclear, anti-SS-A, and anti-SS-B antibody levels. Incisional biopsy of the atrophic eyeball revealed RDD with marked polyclonal plasmacytosis. The patient was diagnosed with RDD accompanied by multisystem involvement, including Sjögren's syndrome (SS), panuveitis, and HP. Treatment with methylprednisolone for several weeks resulted in significant improvement. This is the first reported case of RDD presenting with SS in combination with panuveitis and HP. Although RDD is rarely diagnosed in young patients, interdisciplinary collaboration is essential to prevent a delayed diagnosis.

Facial cutaneous Rosai-Dorfman disease: a case report.

BACKGROUND: Rosai-Dorfman disease (RDD) is a form of non-Langerhans cell histiocytosis in which the activated histiocytes of the lymph nodes and other organs begin to accumulate following excessive production. Bilateral, massive, and painless lymphadenopathy are classic presentations. Systemic RDD is already known to be a rare condition, but isolated cutaneous RDD is extremely rare. We presented a rare and unusual presentations of a disease. CASE PRESENTATION: A 35-year-old Thai female with a 6-month history of a small acne-like lesion that rapidly progressed to 5 cm tumor-like lesions on the face within 3 months. Tissue histology showed a dense dermal infiltration of histiocytes with emperipolesis phenomenon. Immunohistochemistry was positive for S100 protein and CD68 and negative for CD1a. Oral prednisolone (50 mg/day) was initiated with a favorable outcome at the one-month follow-up. However, prednisolone yielded a partial response at 2-month follow-up, leading to application of another modality. CONCLUSION: Although cutaneous Rosai-Dorfman disease is considered benign and well medical responded disease, patients with atypical presentation and rapid growing lesion may necessitate aggressive multimodal treatment.

Isolated Rosai-Dorfman disease of the spine: A systematic literature review.

INTRODUCTION: Rosai-Dorfman disease (RDD) is a rare non-Langerhans cell histiocytosis involving the central nervous system in 5% of cases. Spinal location occurs in less than 1% of extranodal RDD and can be responsible for neurological manifestations. We present a systematic review of cases of isolated spinal RDD. We also report a new case of isolated spinal RDD revealed by spinal cord compression. MATERIALS AND METHODS: The systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline using the MEDLINE and SCOPUS databases and included case reports and case series describing isolated RDD of the spine. RESULTS: There were 53 patients with isolated spinal RDD (including our case). The mean age was 35.85±16.48 years. Neurological deficit was the most frequent clinical presentation (89%). RDD lesions were mainly located in the thoracic spine (51%), then the cervical spine (32%). The lesion was reported to be extradural (57%), intradural extramedullary (26%), intramedullary (7%), and in the vertebral body (10%). Histological examination showed emperipolesis in 73%. Histocytes were positive for S-100 protein in 83%. Treatment was based on surgery 96%), radiotherapy, chemotherapy, and adjunctive steroid therapy were indicated in four, one, and eight cases. After a mean follow-up period of 14.84±13.00 months, recurrence of RDD was noted in 15%. CONCLUSION: Spinal RDD is a rare condition, requiring meticulous histological examination for accurate diagnosis. Complete surgical resection is the treatment of choice. Adjuvant chemotherapy and radiotherapy can also be indicated in patients demonstrating partial improvement following surgery.

[Xanthogranulomatous adrenalitis : A rare and difficult differential diagnosis of adrenal gland tumors]. / Xanthogranulomatöse Adrenalitis : Seltene und schwierige Differentialdiagnose von Nebennierentumoren.

A radiologically diagnosed tumor in a 29-year-old woman with a fever of around 39 °C was operated on under the suspicion of cholecystitis or a liver abscess. A solid tumor was found in the adrenal gland and resected. The frozen section findings did not reveal a clear diagnosis of entity and assignment. Histologically, the tumor was found to consist of densely clustered large histiocyte-like cells with expression of vimentin, CD68, and CD163 as well as negativity for keratin, langerin, and SMA. We diagnosed xanthogranulomatous adrenalitis and discussed the differential diagnoses (Langerhans cell histiocytosis, Rosai-Dorfman disease, malakoplakia, Erdheim-Chester disease).

Rosai-Dorfman Disease, Presenting as a Right Atrial Mass with Involvement of the Tricuspid Valve in a 54-Year-Old Woman.

BACKGROUND Sinus histiocytosis with massive lymphadenopathy (SHML), Rosai-Dorfman disease, or Rosai-Dorfman-Destombes disease (RDD), is a rare non-Langerhans cell of unknown etiology. This report is of a case of isolated SHML, or Rosai-Dorfman disease, presenting as a right atrial mass with involvement of the tricuspid valve in a 54-year-old woman. This case shows the challenges of diagnosing this condition in the heart and the challenges of treating this rare disease with the limited information on the efficacy of the treatment modalities. CASE REPORT A 54-year-old Asian woman presented to the Emergency Department with chest and right upper quadrant pain. Transthoracic echocardiogram and computed tomography angiography showed a right atrium mass at the level of the tricuspid valve, causing moderate-severe regurgitation. Partial tumor debulking with biopsies later showed pink-yellow soft tissue, with histopathology showing histiocytes demonstrating emperipolesis. The tumor was positive for CD68 and S100 and negative for CD1a, consistent with Rosai-Dorfman disease. Subsequently the patient received targeted therapy with cobimetinib, without worsening cardiac function or disease progression. CONCLUSIONS This case highlights the challenging histopathological diagnosis of SHML, or Rosai-Dorfman disease, particularly in non-lymphoid tissue, such as the heart. Obtaining tissue for diagnosis can be challenging in this organ. Treatment is challenging when the mass cannot be extracted completely, like in our case, because other forms of therapies are not well studied and warrant further investigation, such as cobimetinib, which is a MEK pathway inhibitor approved in 2022 by the US Food and Drug Administration for histiocytic neoplasms.

[Pediatric orbital Rosai-Dorfman disease: An unusual case]. / Maladie de Rosai-Dorfman à localisation orbito-palpébrale de l'enfant : à propos d'une observation exceptionnelle.

INTRODUCTION: Rosai-Dorfman disease (RDD) is a sinus histiocytosis with massive lymphadenopathy. This rare condition is a benign disease of unknown etiology. Bilateral orbital localization of RDD is rare. OBSERVATION: The authors report the case of a 6-year-old child who presented with bilateral orbital-palpebral masses associated with chronic cervical lymphadenopathy. There were no laboratory signs of inflammation. Serological and tuberculosis screening tests were negative. Histopathological examination of a lymph node biopsy established a diagnosis of Rosai-Dorfman disease. The patient underwent surgical excision of the orbital lesions followed by long-term corticosteroid therapy. A favorable course was observed, with no sign of recurrence after one year of follow-up. CONCLUSION: Rosai-Dorfman disease is very rare in its bilateral orbital presentation. Histopathological diagnosis remains challenging. In Africa, the presence of chronic oculo-palpebral tumor associated with or without cervical lymphadenopathy must raise the suspicion of Rosai-Dorfman disease after ruling out tuberculosis and lymphoma.

Tracheal resection anastomosis for rare tracheal inflammatory lesions mimicking malignancy: report of 2 cases.

BACKGROUND: Tumor-like lesions of the trachea are rare and challenging in diagnosis and management. Inflammatory myofibroblastoma, also known as Inflammatory pseudo tumors (IPTs), as well as Rosai Dorfman Disease (RDD) are inflammatory lesions that may involve the central airways with variable non-specific clinical features mimicking tumors. CASE PRESENTATION: In this study 2 cases with tumor-like lesions are presented. One case with an inflammatory pseudotumor and the other one with Rosai-Dorfman disease affecting the upper trachea. Both cases were successfully managed with tracheal resection anastomosis. CONCLUSION: Tracheal Inflammatory myofibroblastoma, and Rosai-Dorfman diseases are rare tumor like lesions that present with upper airway obstruction. Despite being benign, these lesions may have features suggestive of malignancy, requiring prompt management. Complete surgical excision by segmental resection and primary anastomosis (if feasible) is the treatment of choice with an optimum outcome.

Treatment of cutaneous Rosai-Dorfman disease with ALA-PDT combined with low-dose oral corticosteroids: A case report.

Cutaneous Rosai-Dorfman Disease (CRDD), a rare form of Rosai-Dorfman Disease (RDD), lacks established treatment guidelines. In this case report, we detailed a successful case of CRDD management in a 50-year-old woman with facial lesions. Our treatment included 5-aminolevulinic acid photodynamic therapy (ALA-PDT) and low-dose oral corticosteroids. Remarkable improvement was evident after six ALA-PDT courses, and a one-year follow-up confirmed sustained remission. This case highlights the potential of combining ALA-PDT with low-dose corticosteroids as a promising therapeutic strategy for CRDD. Further research is necessary to fully elucidate its mechanisms and effectiveness.

Investigating the correlation between small molecular inhibitor utilization, peripheral blood monocytes, and treatment outcomes in Rosai Dorfman disease.

Rosai Dorfman disease (RDD) is a non-Langerhans cell histiocytic neoplasm characterized by sinus histiocytosis with variable emperipolesis. There is a limited understanding of the factors that contribute to disease progression. Traditional management of RDD consists of local therapies (resection, radiation) for localized disease and myelosuppression for systemic disease; targeted medications have also recently been introduced into clinical practice as an additional therapeutic modality. The goals of this study are to compare the impact of targeted therapies to conventional management of RDD and identify trends in laboratory data that may provide insight into disease progression. A retrospective analysis was conducted at a single institution over a 20-year period in 35 adult patients with histopathologic evidence of RDD without confounding secondary malignancies. Clinical data points included laboratory evaluation, molecular diagnostics, imaging, and therapies rendered. Binary data was utilized for statistical analysis and comparison of outcomes by treatment type and utilization of targeted agents. Evaluation of treatment response varied based on anatomic disease sites and baseline imaging modality. To standardize the radiographic analysis, we included PERCIST (if PET was utilized) or RECIST assessments (in the cases of CT or MR imaging). Conventional therapies rendered included local treatment (surgery, radiation, intralesional injections), systemic corticosteroids, immunotherapy, and chemotherapy while targeted agents included only small molecule inhibitors. In this analysis, primary disease was identified in cutaneous, osseous, and CNS structures (17, 11, and 6/35 patients respectively). Management consisted of surgery (12/35 patients), steroid and myelosuppressive therapies (9/35 each), immunotherapy (5/35), and targeted molecular agents (5/35). In evaluating outcomes, the proportion of partial responses was substantially higher in recipients of molecular as compared to conventional therapy (4/5 patients compared to 6/29) while complete responses were more common in the conventional therapy cohort (12/29 compared to 1/5). Lastly, an evaluation of peripheral blood absolute monocytes in all patients who had progressed on therapy identified a significant decrease in pre-progression values as compared to values following therapy re-institution (averages of 0.70 and 0.27 K/µL, respectively; p = 0.0002, 95% CI 0.652-0.2360). Larger-scale studies are needed to further evaluate the relevance of the monocyte trends that were identified in terms of their relationship to disease status. This study is the largest analysis of Rosai Dorfman disease, that we are aware of, from a single institution. In this cohort, the utilization of small molecule inhibitors corresponded to a greater increase in partial responses than conventional therapies, although the opposite effect has been observed in complete responses. This finding can be attributed to the recent introduction of targeted agents and shorter follow-up. We anticipate higher complete response rates with the use of small molecule in ongoing analyses over a longer follow-up period. The recognition of relative monocyte elevation prior to disease progression is an intriguing and to our knowledge, novel finding in the field of Rosai Dorfman disease. Future studies aimed at elucidating the implications of this trend are in progress.

Extranodal Rosai-Dorfman Disease: a rare presentation involving anterior chest wall in a middle-aged female.

Rosai-Dorfman Disease is a rare benign disorder involving overproduction of immune cells, causing swollen lymph nodes and, in rare cases, the sternum. The sternal involvement may cause chest pain and masses. Diagnosis is confirmed through clinical examination, biopsy, and imaging. Treatment options may include surgery, radiation, or steroids. In this case study, we present an unusual example of extranodal Rosai-Dorfman Disease involving the sternum, bilateral clavicles and first three ribs, and pectoral muscle with no associated lymphadenopathy or systemic symptoms in a 57-year-old female. The etiology, pathology, immunohistochemistry, imaging findings, and treatment options of this unique disease are discussed.

Unifocal Type-3 Mixed Histiocytosis in a 10-Years Old Child.

BACKGROUND: Histiocytoses patients present with highly heterogeneous clinical and histopathological pictures requiring multidisciplinary management. Mixed histiocytosis is a recently described group of syndromes defined by the histological overlap of Langerhans cell histiocytosis and other histiocytic proliferations that include three clinically and prognostically different conditions (i.e., Type-1-3 mixed histiocytosis). CASE REPORT: We describe a 10 year-old boy with unifocal (type-3) mixed histiocytosis - Langerhans cell histiocytosis combined with a lesion with features intermediate between Rosai-Dorfman disease and reticulohistiocytosis. Sixty months after excision, the child is disease free. DISCUSSION: Cutaneous type-3 mixed histiocytosis (Langerhans cell histiocytosis with Rosai-Dorfman disease/reticulohistiocytosis) may occur in older childhood, be unifocal, and be cured by surgical excision.

Synchronous occurrence of primary cutaneous B-cell lymphoma and cutaneous Rosai-Dorfman disease in distinct lesions: A unique association.

Rosai-Dorfman disease, also known as sinus histiocytosis with massive lymphadenopathy (SHML), is a rare subtype of reactive histiocytosis which is seldom associated with Hodgkin's and non-Hodgkin's lymphomas. To date, the coexistence in the same patient of extra nodal SHML and primary cutaneous B-cell lymphoma (PCBCL) has been reported in the literature, as metachronous diagnosis in the anatomical area of the original PCBCL or synchronous occurrence in the same lesions. However, no data have been published as for synchronous occurrence of the two pathological entities in distinct anatomical sites. Herein, we report the first ever described synchronous occurrence of PCBCL and SHML, detected in distinct lesions, affecting the same patient. The complete resolution of the patient's PCBCL after rituximab treatment and the concomitant regression of SHML suggest that this clinically benign reactive histiocytic proliferation, potentially triggered by the lymphoma microenvironment itself, may take place not only in the site of the PCBCL lesion, but also in other distant areas not directly affected by the primary cutaneous lymphoma.

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.