Large Histiocytes Research Articles

La maladie de Destombes-Rosai-Dorfman : évolution du concept, classification et prise en charge

Rosai-Dorfman disease (RDD) was first described by the French pathologist Paul Destombes in 1965. It frequently affects children or young adults and is characterized by the presence of large histiocytes with emperipolesis. More than 50 years after this first description, the pathogenesis of this rare disease is still poorly understood. The revised classification of histiocytoses published in 2016 identified various forms of RDD, from familial RDD to IgG4-associated RDD. Almost 90% of the patients with RDD have cervical lymph nodes involvement although all the organs may virtually be involved. Outcomes are typically favorable. Treatments may be necessary in case of compression or obstruction, and are not well codified. The main therapeutic strategies rely on surgery, radiotherapy, steroids, immunosuppressive drugs or interferon-alpha and cladribine.

Isolated Langerhans Cell Histiocytosis of Thyroid-Masquerading as a Thyroid Neoplasm - A Rare Case Report

Langerhans Cell Histiocytosis (LCH) is a rare neoplastic disease of unknown etiology characterized by oligoclonal proliferation of langerhans cells with a varying incidence rate of 4-5.4 per 1 million individuals. LCH occurs in localised and multifocal forms. LCH lesions were first described in the year 1893, they are composed of large histiocytes with abundant cytoplasm intermixed with lymphocytes and eosinophils. Diabetes insipidus is the most common endocrinological abnormality of LCH. Other manifestations such as hypothalamic/pituitary axis disturbance and anterior pituitary deficiency can occur resulting in secondary or tertiary hypothyroidism. Cases of LCH with isolated thyroid involvement are very rare. We present a case of LCH, in a 42-year-old female who had a nodular thyroid swelling since one and a half year with euthyroid status. Total thyroidectomy specimen was received with a clinical diagnosis of thyroid neoplasm. Histopathology revealed langerhans histiocytes both mononucleated and multinucleated with prominent nuclear grooves, accompanied by good number of eosinophils and lymphocytes. Histopathology diagnosis of LCH was given supported by IHC S-100 and CD 1a positivity. Since, it’s a rare entity it needs to be distinguished from its closer mimics non Hodgkin’s lymphoma and Rosai Dorfman’s disease. Treatment of choice is surgical resection, but there is no evidence of improved outcome on usage of adjuvant chemoradiotherapy for primary thyroid LCH post resection. So, more case reports and articles are recommended to acess treatment regimen for better outcome.

Case for diagnosis. Solitary violaceous nodule on the toe

Reticulohistiocytomas represent a group of benign histiocytic dermal proliferations, which occur either sporadically as solitary cutaneous nodules or, when multiple, in association with systemic disease. Due to its nonspecific clinical presentation, reticulohistiocytoma may mimic other benign or malignant skin neoplasms; therefore, in most cases, a biopsy is needed in order to establish the correct diagnosis. The histology is typically characterized by the presence of large histiocytes with abundant eosinophilic cytoplasm with immunohistochemical profile positive for CD68, CD163, and vimentin. The authors report the case of a patient with solitary reticulohistiocytoma with illustrative clinical, dermoscopic, and histologic features.

Analysis of the clinical characteristics and efficacy of 20 cases of extranodal Rosai-Dorfman disease in head and neck

Objective: To analyze the clinical characteristics and efficacy of extranodal Rosai-Dorfman disease in head and neck. Methods: Clinical and pathological features and follow-up of patients who were diagnosed as RDD at Beijing Tongren Hospital of Capital Medical University between May 2008 and November 2016 were analyzed retrospectively. Results: There were a total of 20 extranodal RDD patients in head and neck including 14 females and 6 males, aged from 27 to 86 years (mean 52.5 years). Nose (14 cases) and throat (5 cases) were most commonly involved organs and 5 patients had 2 or more organs involved. Diagnosis depends on biopsy. Histopathologically, the lesions of RDD were characterized by the presence of large histiocytes with emperipolesis. The large sinus histiocytes were positive for S-100 and CD68 protein staining. Diagnostic Errors in 13 patients and operations in all patients were happened. More than 1 operation was performed in 9 recurrence patients. Eight patients were treated by Glucocorticoids and immunosuppressive agents. All the patients were alive until Feb 2017. Conclusion: Extranodal RDD in head and neck is known as a rare benign idiopathic proliferative disease. Nose is the most common site involved, and recurrence easily. It is diagnosis depending on histopathological report. Operation is first choice in diagnosis and treatment now. Glucocorticoids and immunosuppressive agents are effective in recurrence patients.

Childhood macrophagic myofasciitis: A series from the Indian subcontinent.

Macrophagic myofasciitis (MMF) is a rare disorder, reported mainly in European adults, with occasional childhood cases. We report a series of 6 patients with pediatric MMF from the Indian subcontinent. Clinical details, creatine kinase levels, and results of electromyography are described for patients diagnosed with MMF. Fresh-frozen and formalin-fixed muscle biopsies were evaluated by hematoxylin-eosin staining, histochemistry, immunohistochemistry, and electron microscopy. Six of 2,218 muscle biopsies were diagnosed as MMF; patient charts were reviewed. The 6 patients were all children; all presented with hypotonia and/or motor delay. Mean age at diagnosis was 16.2 months. There were 4 boys and 2 girls. All had a history of hepatitis B vaccination. Histopathology revealed infiltration by sheets of large periodic acid-Schiff stain-positive histiocytes. Ultrastructural examination demonstrated needle-shaped crystals within histiocytes. One patient had a co-existent neuromuscular disorder, merosin-deficient congenital muscular dystrophy. MMF is a rare inflammatory myopathy that should be considered in the differential diagnosis of congenital myopathies in children. Muscle Nerve 56: 71-77, 2017.

Soft Tissue Rosai-Dorfman Disease with Unusual Histopathologic Features: A Case Report

Rosai-Dorfman disease is a rare proliferative histiocytic disorder of unknown etiology. It is a unique disorder of the lymph nodes but extranodal sites such as bone, skin, central nervous system, upper respiratory tract and soft tissue may be affected. Rosai-Dorfman disease is presented with massive, symmetrical cervical lymphadenopathy, fever, leucocytosis, elevated sedimantation rate and hipergamaglobulinemia. Soft tissue presentation can masquerading as a sarcoma. 61 year old women referred with painless left thigh mass to our hospital. After a excisional biopsy histopathologic results showed sheets of histiocytes with emperipolesis admixed in a mixture of inflammatuary cells including plasma cells and lymphocytes. Additionally, we observed pseudovascular spaces and asteroid bodies in large histiocytes. After surgery the patient has been followed up for 1 year postoperatively, without any sign of reccurence. We herein report a case of soft tissue Rosai-Dorfman disease wich presented with unusual features such as pseudovascular spaces and asteroid bodies in histiocytes.

Clinicopathologic analysis of extranodal Rosai-Dorfman disease of breast: a report of 12 cases

To investigate the clinicopathologic features, diagnosis and differential diagnosis of extranodal Rosai-Dorfman disease(RDD)of the breast. Twelve cases of extranodal RDD of the breast were analyzed using hematoxylin-eosin stain and immunohistochemical staining.The morphological features and immunophenotype were observed by light microscopy, accompanied with a review of the literature. Twelve cases of extranodal RDD of the breast are presented. The patients were women and their ages ranged from 15 to 55 years (mean =37 years). Except one patient with involvement of the right breast and ipsilateral axillary lymph nodes, other eleven patients' disease confined to the breast. Seven cases located in the right breast, the other five cases in the left breast. Microscopically, it showed a typical morphology, characterized by diffuse infiltration of large histiocytes, lymphocytes and plasmocytes that formed irregular nodular structure with light and dark appearance under microscope. Spindling of histiocytosis often arranged in a vague storiform with prominent fibrosis, accumulation of foamy histiocytes and scattered atypical nuclei. The characteristic histocytes and emperipolesis could not be seen obviously in extranodal RDD of the breast.Immunohistochemical staining showed histocytes were strongly positive for S-100 protein, CD68 and CD163, while negative for CD1a. Extranodal RDD of the breast is very rare. Because of unconspicuous emperipolesis and lack of specificity in clinic and images, extranodal RDD of the breast is easy to be misdiagnosed as other histiocytosis. The microscopic differential diagnosis includes idiopathic granulomatous mastitis, infective granulomas, langerhans cell histiocytosis, IgG4 related sclerosing disease, Erdheim-Chester disease, benign fibrous histiocytoma, malignant fibrous histiocytoma and Hodgkin Lymphoma. Light and dark appearance under microscope is the important clue in diagnosis of extranodal RDD in breast. Immunohistochemistry is also helpful.

Extranodal Rosai-Dorfman Disease: Clinicopathologic Series of 10 Patients With Radiologic Correlation and Review of the Literature.

To describe the radiologic and clinicopathologic features of extranodal Rosai-Dorfman disease (RDD) in our patient population. Via a data mining engine, we evaluated 13 cases of extranodal RDD in 10 patients treated at our institution from 2000 to 2014. There was a marked female predominance (90%) in our series. The most common clinical presentation was a palpable, painless mass, which often simulated a neoplasm. Only two cases occurred in children. Multicentric and recurrent disease were uncommon. Histologically, all cases showed large histiocytes with emperipolesis in a mixed inflammatory background, with areas of dense, storiform collagen fibrosis. Positive S-100 and CD68 with negative CD1a in histiocytes are characteristic. Extranodal RDD is rare and its manifestations varied. It may constitute a clinical and pathologic diagnostic challenge. Clinical suspicion and recognition of its histologic features are necessary for correct diagnosis and avoiding unnecessary treatment. Resection is curative in most cases.

Cutaneous Rosai-Dorfman disease in a middle-aged man: A case report.

The present study describes a case of cutaneous Rosai-Dorfman disease (CRDD). The clinical manifestations and therapeutic options of CRDD vary, and the etiology of the disease is still unknown. The clinical manifestations include single or multiple yellow-red to brown or purple papules, nodules and/or plaques, with the face being the most frequently affected site. A 52-year-old man presented with an 8-month history of multiple lesions on his face. Physical examination revealed a number of yellow-red papules and nodules, the majority of which had coalesced into plaques. The histological finding from a red papule showed a dense, dermal infiltrate, which was predominantly composed of large histiocytes, strongly positive for S-100 and cluster of differentiation (CD)68 but negative for CD1a, mixed with aggregates of lymphocytes and scattered plasma cells and eosinophils. The patient showed only a marginal improvement with a month of oral, low-dose prednisone.

Clinical analysis of hard metal lung disease

To analyze the clinical features and investigate the clinical diagnostic methods of hard metal lung disease (HMLD), then provide reference for the diagnostic criteria of occupational HMLD. Retrieved the open published case reports associated with HMLD from January, 2000 to June, 2014. Regarding the ages, sex, types and years of work, clinical features and laboratory results for analyzing. Collected 21 clinical cases of HMLD belonged to 6 internal reports and 15 oversea reports. Among them 15 male and 6 female, ages were from 22 to 58, length of service between 1 year and 43 years. Clinical presentations included cough (20 cases), dyspnea on progressive (10 cases), and pulmonary function testing showed a restrictive abnormality. The imaging features presented as bilateral areas of ground-glass attenuation, diffuse small nodules, extensive reticular opacities and traction bronchiectasis. The finding of giant cell interstitial pneumonia (GIP) was almost pathognomonic for hard metal pneumoconiosis. The main pathological findings contained a different levels of lymphocyte, acidophilic cell infiltration, hyperplasia of fibrous tissue and numerous large multinucleated histiocytes which ingested inflammatory cells were admixed with macrophages. 16 cases of the 21 reports showed GIP. Clinical presentations include cough and dyspnea on progressive, and pulmonary function testing show a restrictive abnormality. The imaging features present as bilateral areas of ground-glass attenuation, areas of consolidation, diffuse small nodules, extensive reticular opacities and traction bronchiectasis. The prime pathological findings contain interstitial pneumonia with intra-alveolar macrophages and a large amount of multinucleated histiocytes.

Sinus histiocytosis and massive lymphadenopathy (Rosai-Dorfman disease) in an 8 year old female child: a rare case report

Introduction: Sinus histiocytosis with massive lymphadenopathy is an infrequent, self-resolving histoproliferative disorder of benign nature, also known as Rosai–Dorfman Disease. The typical manifestation of this disease includes bilateral, progressive cervical lymphadenopathy along with pyrexia. Laboratory manifestations consist of raised erythrocyte sedimentation rate, leukocytosis and hypergammaglobulinemia. Case report: An 8 year old female child presented with progressive, painful cervical and submandibular lymphadenopathy of three months duration. There was polymorphic leukocytosis and anemia along with raised Erythrocyte sedimentation rate and hypergammaglobulinemia. Fine Needle Aspiration cytology revealed sinus histiocytosis with massive lymphadenopathy, which was confirmed by the cervical lymph node biopsy. The histopathology revealed dilated sinuses filled with lympho plasma cells, large histiocytes and engulfed neutrophils (Emperipolesis). Conclusion: Massive, progressive bilateral cervical and sub mandibular lymphadenopathy, suggesting Sinus histiocytosis and massive lymphadenopathy-Rosai–Dorfman Disease. This was confirmed by Cytology, histopathology and immuno- histochemistry.

Rosai-Dorfman disease of the distal radius in a child: A case report and review of the literature

Rosai-Dorfman disease (RDD) is a non-neoplastic self-limiting disease of bone marrow stem cell origin characterised by cervical lymphadenopathy. Primary osseous lesions are rare and the condition can mimic various solitary bone lesions radiologically. A 15-month-old child presented with an isolated, well-defined, lucent lesion of the distal radius. Histology demonstrated numerous large histiocytes with intracytoplasmic lymphocytes, plasma cells and neutrophils. Immunohistochemistry showed CD 68 immunopositivity, confirming RDD. Healing of the lesion was seen 6 months post-operatively following curettage. Isolated extranodal osseous lesions are very rare in children and can mimic several osseous conditions.

Hematologic lesions in urine cytology

Bladder infiltration by leukemia or lymphoma is rare and can mimic benign processes such as follicular cystitis (FC). Eight benign and malignant hematologic diseases encountered in urine cytology were retrospectively reviewed for clinical, radiographic, and cytologic findings. There were 2 cases of acute myeloid leukemia, 2 cases of diffuse large B-cell lymphoma, and 4 cases of FC. The most common presenting symptom was hematuria. Imaging findings included echogenic debris within the bladder or an adjacent soft tissue mass in acute myeloid leukemia cases and bladder wall thickening in diffuse large B-cell lymphoma cases. No FC cases had any imaging abnormalities. Cytologic material of the leukemia cases showed numerous myeloid blasts with markedly increased nuclear-to-cytoplasmic ratios, centrally located nuclei, inconspicuous nucleoli, nuclear indentations, and some irregular nuclear membranes. The background showed sparse urothelial cells and histiocytes. Both lymphoma cases showed a discohesive population of atypical large lymphoid cells with irregular nuclear borders and prominent nucleoli. The FC cases had a background lymphoid cell population with a maturation spectrum from small lymphocytes to large lymphoid cells (immunoblasts) and histiocytes including tingible body macrophages. Additionally, there were many mature squamous cells and reactive urothelial cells. Bladder leukemia, lymphoma, and FC are infrequently encountered on urine cytology. FC can be distinguished from a hematologic malignancy by the presence of a lymphocytic maturation spectrum and tingible body macrophages. Radiologic abnormalities are associated with malignant processes; however, discrete bladder masses are usually not identified.

Radiological and clinicopathological analysis of intraspinal primary Rosai-Dorfman disease

Background Rosai-Dorfman disease (RDD), also known as sinus histiocytosis with massive lymphadenopathy (SHML), is a non-neoplastic histiocytic proliferation predominantly affecting lymph nodes, and usually presents with massive painless cervical lymphadenopathy accompanied by fever and weight loss. Extranodal involvement occurs in over 40% of patients; however, isolated extranodal disease without lymph node involvement is unusual. Although extranodal involvement has been reported in diverse sites, central nervous system manifestation, particularly in spinal cord is distinctly rare. It is a diagnostic challenge for radiologists and histopathologists to differentiate RDD from other spinal lesions because of its similarities in radiological and histological findings. Herein we describe a case of unusual isolated RDD in spinal cord. The radiology and clinicopathology of this lesion, as well as its differential diagnosis are discussed. Methods The clinical manifestation of a patient with intraspinal primary RDD occurring C 3-6 level was presented retrospectively. Gross resected mass was routinely paraffin-embedded and stained with hematoxylin and eosin. Dako EnVision immunohistochemical staining system was used to detect the tumor antigen expressions, including S-100 protein (S-100), CD1a and CD68 (KP-1). Results A 25-year-old female patient presented with 3-month history of numbness and weakness in both upper limbs associated with an increasing neck back pain. There was no fever and lymphadenopathy found in the patient. MRI of the whole spine revealed a subdural mass extending from C 3 to C 6 level of cervical spinal cord with homogeneous enhancement after contrast administration. Laminectomy and midline opening of the dura were performed. The subdural lesion appeared to have no capsule and attach the dura mater. The lesion was removed totally. Under the microscopic examination, dense fibrosis and intense chronic inflammation with focal neutrophilic infiltrates were noted. The clusters of large histiocytes with eosinophilic, finely granular cytoplasm and multinucleate giant cells were also observed in the lesion. Emperipolesis with intact lymphocytes within the cytoplasm of the large histiocytes were present. Mitotic activity and necrotic area were not observed. Special stains for organisms were negative. By immunohistochemical analysis, the characteristic histiocytes were positive for S-100 and CD68 and negative for CD1a. Based on clinical presentations and histological findings, a final histological diagnosis of primary RDD in spinal cord was made according to the criteria of WHO classification. The patient did not receive chemotherapy and radiotherapy, and attended follow-up for 12 months, without any neurological deficit or signs of recurrence. Conclusions Isolated intraspinal RDD is rare. The definite diagnosis of this lesion should be made under the microscopical examination because the preoperative radiological appearance of the lesion does not differ from other lesions occurring in spinal cord, such as inflammatory pseudotumor, meningioma and lymphoma. Although good prognosis is obtained from gross total resection in most of reported patients with this lesion, recurrence could be found in individual cases, and chemotherapy and (or) radiotherapy had been applied for a few cases with multiple organs involvement to control the progression of lesion. Due to the rarity of its site, the strictly differential diagnosis should be made when the isolated RDD is encountered in spinal cord. doi: 10.3969/j.issn.1672-6731.2014.04.011

Multiple cutaneous reticulohistiocytoma in middle aged female

Multiple cutaneous reticulohistiocytoma (MCR) and multicentric reticulohistiocytosis (MR) are rare, idiopathic histiocytic granulomatous disorders presenting in a spectrum. A 35-year-old female presented with multiple, firm, discrete, asymptomatic nodules, 1-2 cm in size over face, back, abdomen, thighs, and legs. There were no systemic symptoms. Histopathology of a nodule over trunk showed diffuse, dense infiltrate of large histiocytes, and histiocytic giant cells. The histiocytes had rounded vesicular nuclei and abundant pink homogenously stained ground glass cytoplasm. The diagnosis of MCR was made. Systemic evaluation did not reveal any abnormality. Considering the cosmetic appearance of facial lesions, patient was referred to the plastic surgeon. No treatment was advised for rest of lesions and patient was asked to review every 6 months or if any new complaints develop.

Rosai-dorfman disease in thoracic spine: a rare case of compression fracture.

Sinus histiocytosis with massive lymphadenopathy known as Rosai-Dorfman disease is characterized by painless bilateral cervical lymphadenopathy. Extranodal manifestations are uncommon and spinal involvement is rare. A 15-year-old man presented with intermittent midthoracic back pain only. He had no specific findings on neurologic examinations, hematologic and biochemical laboratory tests. Radiological examination of thoracic spine revealed collapse of T6 vertebrae with thoracic kyphosis and osteolytic lesion of T12 vertebra body. He underwent a removal of bone tumor, anterior reconstruction with mesh and pedicle screw fixation via posterior approach for pathologic confirmation and stabilization. Histopathologic study of the lesion revealed focal infiltration of large histiocytes showing emperipolesis. Immunochemistry stain of histiocytes was positive for CD68 and S-100 but negative for CD1a. This report presents a rare case and literature review of extranodal Rosai-dorfman disease in thoracic spine.

Gastric Xanthelasma, Xanthoma, and Xanthomatosis

BackgroundXanthelasma is a yellowish deposit of cholesterol underneath the skin, usually on or around the eyelids, which is associated with hyperlipidemia. In the stomach, xanthelasma and xanthoma are used interchangeably, and referred to asymtomatic benign endoscopic findings, which are not associated with hyperlipidemia. Gastric xanthomatosis is rare. Patient and methodsWe present the endoscopic and histopathological features of gastric xanthomatosis in a 68-year-old man with a history of peptic ulcer disease and previous antrectomy. ResultsGastric xanthelasma and xanthoma present as solitary white or yellow flat mucosal lesions with fern-like surface features. These discrete lesions are usually found in the antrum. Gastric xanthomatosis presents with multiple small white or yellow mucosal patches or nodules. Histopathologic features include large foamy histiocytes containing a mixture of lipids in the mucosa and submucosa. ConclusionsGastric xanthelasma, xanthoma, gastric xanthomatosis are benign incidental endoscopic findings and are not associated with hyperlipidemia.

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Introduction: We are presenting a new case of hypersensitivity pneumonitis(HP) in a occupational nail worker.HP is a granulomatous reaction in terminal airways, alveoli and surrounding interstitium. Although farmer's lung is the most common form of HP affecting 0.4-7% of farming population, the incidence of HP in nail worker is unknown and it is the first reported case of HP due to exposure to human nail. Case Presentation: 31 year old African American woman presented with worsening dyspnea on exertion, audible wheezing, non productive cough for 2 weeks. Her symptoms had been worsening since she was working long hours in her nail salon.She recently started working in the saloon since 3 months and her work included nail buffing and filing. She was exposed to extensive nail dust.Past medical history included morbid obesity, type 2 DM.Metformin was her only medication and there was no known allergy.Family history was negative for any lung disease or autoimmune disease.She smoked 3-5 cigaretts per day and quit 2 weeks prior. She denied use of alcohol or recreational drugs.Her condition worsened requiring admission to intensive care unit and mechanical ventillation with 100% O2. CTA thorax ruled out PE but showed extensibe ground glass opacities mostly affecting lingula and bilateral lobes.She was started on broad spectrum antibiotics. Results of respiratory viral panel,Legionella,HIV,ANA,RF, sputum culture were negative.Bronchoscopy was normal and BAL was negative for Mycobacterium, Legionella, fungi. Cytology from BAL revealed respiratory bronchiolitis. She failed to improve and she was emperically treated with IV Methylprednisolone to which she responded.Finally she underwent VATS with multiple lung biopsies.Biopsy showed scattered foci of non caseating granulomatous,alveolar pneumocyte hyperplaisa, large histiocytes with foamy cytoplasm in the alveoli.Special stains for fungal and mycobacterium including AFB,GMS and PAS were negative. Immunostains for S100,CD1a,actin,and HMB45 were negative.She continued to improve and she was discharged on oral prednisone.She was no more exposed to the nail dust and was at her baseline health in 4 weeks follow up. Discussion: HP in nail workers is not a well known clinical entity and there are no gold standard diagnostic tests.Though there are some case reports of HP to Trichophyton rubrum,it is the first case reported to the best of our knowledge. Although nail workers are exposed to various chemicals in addition to the nail dust which can confound the problem, our patient didnot have exposure to chemicals. Temporal relationship of symptoms with work, no other chemical exposure, typical radiological findings, supportive pathological findings and resolution of symptoms after removal from exposure strongly suggest towards the diagnosis.

Exophytic Tracheal Mass. A Rare Presentation of Rosai–Dorfman Disease

A 77-year-old female with a history of previously treated breast cancer presented with intractable cough for 6 weeks and no other associated symptoms. Physical examination disclosed coarse breath sounds throughout both lung fields, but no wheezing or stridor. Routine laboratory studies were notable only for an elevated white blood count of 12,400/ml with 86.3% neutrophils. Computed tomographic chest imaging (Figure 1) showed a roughly spherical exophytic mass arising from the anterior wall of the trachea with near occlusion of the airway. Associated mediastinal and left hilar adenopathy was also observed. Given the history of breast cancer, metastatic disease was considered a strong possibility. A primary tracheal malignancy was also considered as part of the differential diagnosis. As the patient was stable, flexible fiberoptic bronchoscopy was performed in the bronchoscopy suite under moderate sedation. The lesion was visualized in the mid-trachea (Figure 2). An electrocautery snare (Olympus, Center Valley, PA) was then used to ablate and debulk the mass (Figure 3). The patient tolerated the procedure uneventfully. The next day, she was taken to the operating room. With the assistance of an anesthesiologist, she underwent direct intubation with a rigid tracheoscope (BryanDumon 12/11 mm; Bryan Corporation, Woburn, MA) under general anesthesia. Jet ventilation was used throughout the procedure. The remaining tumor was cored out with the rigid scope. A Xomed microdebrider (Medtronic, Minneapolis, MN) was used to further shave down the tumor along the anterior and lateral walls of the trachea. Argon plasma coagulation was used on the residual tumor surface to achieve coagulation (Figure 4). There was no bleeding and the patient was extubated uneventfully. Histological examination of biopsy samples showed that the mass consisted predominantly of large histiocytes with ample finely vacuolated eosinophilic cytoplasm. A mixed inflammatory infiltrate consisting of lymphocytes, plasma cells, and neutrophils was interspersed in between the large cells. Emperipolesis was noted (Figure 5). Immunohistochemical stains were positive for CD68 and S-100 (Figure 5) and negative for pan-cytokeratin AE1/AE3 and pan-melanoma cocktail. The morphology and immune profile of the mass confirmed a diagnosis of Rosai–Dorfman disease. Adjunct treatment with prednisone (60 mg daily for 2 wk) was initiated and she was discharged home. Repeat imaging 5 months later showed that the tumor had regrown. Low-dose radiation therapy (20 Gy

Rosai-Dorfraan disease in nasal cavity：two case reports and literature review

Objective To study the clinical manifestations, pathological features and differential diagnosis of extranodal Rosai-Dorfman disease （RDD） in nasal cavity. Methods The clinical, pathologic, immunohistochemical and special staining features of 2 cases of RDD were evaluated and related literatures were reviewed. Results Extranodal RDD in nasal cavity and various degrees of stromal fibrosis were seen association with mixed inflammatory cells （especially plasma cells）.The large polygonal histiocytes varied in number and were distributed in clusters or patches. Conclusion Extranodal RDD of nasal cavity is relatively rare and pathologic diagnosis may be difficult. It can easily mimic rhinoscleroma, hyperplasia of langerhans cells, granulomatous inflammation and fibrous tumors. Immunohistochemical and histochemical study is helpful in the differential diagnosis. Key words: Rosai-Dorfman disease; Nasal cavity; Histiocytosis; Immunohistochemistry; Differentialdiagnosis