Rosai-Dorfman disease with infiltration of IgG4-bearing plasma cells presenting as laryngeal-nasal masses and cervical lymphadenopathy: A case report

RATIONALE

Rosai-Dorfman disease (RDD) is a rare and self-limiting condition caused by the non-neoplastic proliferation of histiocytes/phagocytes in the sinusoids of lymph nodes and in extranodal tissues. Of the extranodal involvement, laryngeal involvement is extremely rare. Because of its rarity and nonspecific clinicoradiologic features, RDD is often difficult to differentiate from other benign or malignant lymphoproliferative diseases. We present a case of RDD with infiltration of IgG4-bearing plasma cells manifesting laryngeal and nasal masses with cervical lymphadenopathy.

PATIENT CONCERNS

A 45-year-old male patient presented with recurrent epistaxis and airway disturbance.

DIAGNOSES

On endoscopy, there were submucosal masses in both nasal cavities and both sides of subglottic larynx. On neck CT, there were well-defined, enhancing soft tissue masses in both nasal cavities and both sides of subglottic larynx, resulting in mild airway narrowing. In addition, multiple enlarged lymph nodes showing homogeneous enhancement were noted in both parotid glands and both internal jugular chains. All lesions demonstrated marked FDG-uptake on PET/CT. Therefore, the initial radiologic differential diagnoses included lymphoma and IgG4-related disease. Biopsy was performed on the nasal and laryngeal lesions, and they revealed RDD with infiltration of IgG4-bearing plasma cells.

INTERVENTION

The patient underwent surgical resection of the masses in the nasal cavity and larynx to relieve airway narrowing.

OUTCOMES

After surgery, airway obstruction was much improved and the patient was asymptomatic. On outpatient follow-up, he exhibited a stable condition and had no dyspnea on exercise.

LESSONS

Clinical awareness and suspicion are important for the accurate diagnosis and management of patients with homogeneous masses in the larynx or nasal cavity, even if there is no combined cervical lymphadenopathy.

Cutaneous Rosai - Dorfman disease in a patient with late syphilis and cervical cancer - case report and a review of literature

BACKGROUND

Cutaneous Rosai - Dorfman disease (CRDD) is extremely rare variant of idiopathic histiocytic proliferative disorder, which may manifest as a non-specific macules, papules, plaques or nodules ranging in size and colour from yellow - red to red -brown.

CASE PRESENTATION

A 52-year-old female presented with three gradually enlarging, reddish - brown nodules on the right upper extremity lasting six months. The patients denied fever, weight loss, malaise. Clinical examination and imaging tests showed no sign of lymphadenopathy. A biopsy specimen of a nodule showed a dense dermal polymorphic infiltrate with numerous histiocytes exhibiting emperipolesis phenomenon. Immunohistochemical staining of the histiocytes showed S-100 protein (+), CD68(+), but CD1a (-). Aforementioned findings were consistent with CRDD characteristics. Additionally, a routine serological screening and confirmatory serological tests for syphilis were positive. Syphilis of unknown duration was diagnosed. The IgG antibodies titre against Chlamydia trachomatis was elevated. An isolated sensory impairment over the right trigeminal nerve was found on neurological consultation. Comprehensive gynaecological assessment was carried out because of patient's complaints of bleeding after sexual intercourse and led to diagnosis of cervical cancer. The initial therapy with methotrexate was discontinued after three months due to neutropenia. Further therapy with dapson was ineffective, therefore complete surgical excision was recommended.

CONCLUSIONS

CRDD is a rare, benign condition especially difficult to diagnose due to lack of general symptoms and lymphadenopathy. Histopathologic examination with immunohistochemical staining, exhibiting characteristic and reproducible findings play a key role in establishing an accurate diagnosis. In the presented case activated histiocytes demonstrated in a lesional skin might be a response to immune dysregulation related to chronic, untreated sexually transmitted infections and cancer.

[Expression of IgG4 in Rosai-Dorfman disease and its significance]

OBJECTIVE

To study the prevalence of IgG4-positive plasma cells in Rosai-Dorfman disease and to assess the association between Rosai-Dorfman disease and IgG4-related sclerosing disease (IgG4-SD).

METHODS

The clinicopathologic features of 12 tissue samples of Rosai-Dorfman disease (11 extranodal and one nodal) from nine patients were reviewed. The degree of fibrosis and occlusive phlebitis was studied by HE staining. The expression of IgG4 and IgG in plasma cells were studied by immunohistochemistry (EnVision) and quantitatively analyzed by medical image analysis system.

RESULTS

Nine tissue samples showed different degree of fibrosis (four tissue samples were mild, one tissue sample was moderate and four tissue samples were severe) and two tissue samples showed occlusive phlebitis in the lesional tissue. Immunohistochemical study showed marked infiltration by IgG4-positive plasma cells (> 50 per high-power field) in four tissue samples, moderate infiltration (30 to 50 per high-power field) in two tissue samples, mild (10 to 29 per high-power field) in three cases and negative infiltration (< 10 per high-power field) in three tissue samples (P < 0.01). Three tissue samples fulfilled the diagnostic criteria of IgG4-SD (> 50 IgG4-positive plasma cells per high-power field and IgG4-to-IgG ratio > 40%), including one tissue sample each of Rosai-Dorfman disease in the left facial skin, above the left eye socket, and in the right parotid.

CONCLUSIONS

Some cases of Rosai-Dorfman disease fulfill the diagnostic criteria and show the histologic features of IgG4-SD. They may represent members of the IgG4-SD spectrum. The detection of IgG4-positive plasma cells in the lesional tissues of Rosai-Dorfman disease may have clinical pathological significance.

Cutaneous Rosai-Dorfman disease

A 63-year-old woman developed multiple nodules at the site of a recently biopsied proliferation of CD 68+ histiocytes. Clinical lymphadenopathy was not present on physical examinaton or on computed tomography scans. A subsequent skin biopsy specimen showed changes consistent with Rosai-Dorfman disease. Rosai-Dorfman disease is a benign, histiocytic proliferative disorder also known as sinus histiocytosis with massive lymphadenopthy. A particularly rare, extranodal, purely cutaneous form has been described. Spontaneous regression tends to occur over months to years, with surgical intervention remaining the most effective treatment. Documented success with a number of other therapies has been reported, which include systemic high-dose thalidomide in extensive cutaneous disease.

Rosai Dorfman disease--a clinico-pathological presentation

Rosai Dorfman disease (RDD) or sinus histiocytosis with massive lymphadenopathy (SHML) is a rare disorder that typically manifests as lymphadenopathy and systemic symptoms. The authors report a 45 year old lady who presented with nasal mass and generalised lymphadenopathy. Histopathological examination demonstrated lymphophagocytosis (emperipolesis) consistent with a diagnosis of RDD. The clinical and histologic aspects of the disease are discussed as a rare cause of generalised lymphadenopathy.

Multifocal, extranodal sinus histiocytosis with massive lymphadenopathy: an overview

CONTEXT

This article provides an overview of the major pathologic manifestations of sinus histiocytosis with massive lymphadenopathy, including patient characteristics and current knowledge about its pathogenesis, with an emphasis on multifocal and extranodal presentation. Sinus histiocytosis with massive lymphadenopathy is a rare, nonneoplastic, idiopathic, proliferative histiocytic disorder; recognition of this disorder is important to avoid misinterpretation and subsequent unnecessary treatment. This is especially true for primary extranodal manifestation of this rare disorder. Although accurate diagnosis of this entity requires a correlation of clinical, radiologic, laboratory, and pathologic studies in most cases, it remains a disorder primarily defined by its histopathologic features and pathologic manifestations, which are key to the diagnosis.

OBJECTIVE

To summarize the scientific literature, provide a concise review, and emphasize the diagnostic histopathologic features of extranodal sinus histiocytosis with massive lymphadenopathy.

DATA SOURCES

A comprehensive literature review was undertaken to summarize the clinical and pathologic features of this disorder.

CONCLUSIONS

Sinus histiocytosis with massive lymphadenopathy is characterized by a rare, acquired, nonmalignant proliferation of distinctive histiocytes that present with lymphadenopathy or extranodal disease, primarily in children and young adults. It exhibits a broad range of clinical presentations, thus eliciting a wide differential diagnosis. The diverse clinical manifestations and frequent association with subtle or severe immunologic abnormalities suggest an immune-mediated cause. Additional studies are needed to characterize the interplay between death receptors and cytotoxic mediators and to further elucidate the loss of immune hemostasis that may underlie idiopathic histiocytic proliferations such as this.

Spinal epidural Rosai-Dorfman disease preceding by relapsing uveitis: a case report with literature review

STUDY DESIGN

Case report.

SETTING

Tertiary referral center hospital in Taiwan.

OBJECTIVES

To report a case of spinal Rosai-Dorfman disease (RDD) presenting with paraparesis and also preceding by relapsing uveitis for 6 months. A thoracic laminectomy was performed to remove the solid mass. The pathological diagnosis reveals infiltrating histiocytes, emperipolesis and positivity for S-100. There is no recurrence 1 year later with MR imaging.

CONCLUSIONS

The relapsing idiopathic uveitis may be a prodrome for this unusual disease, because RDD is associated closely to defective immunogical response. Early and accurate diagnosis of CNS RDD may reverse the neurologic deficits by early decompression.

Parvovirus B19 detected in Rosai-Dorfman disease in nodal and extranodal manifestations

Sinus histiocytosis with massive lymphadenopathy (SHML), also designated as Rosai-Dorfman disease (RDD), is a rare benign reactive lymphoproliferative disorder. It is defined by a characteristic histopathology with sinus histiocytosis and haemophagocytosis known as emperipolesis. In histiocytes S100 is strongly expressed, whereas CD1a staining typically is negative. The disease mainly manifests at a single lymph node; however, multilocular and extranodal affection can occur. Causative infectious agents, and virus infections in particular, have repeatedly been suspected, although until now the origin of the disease has been unclear. Four cases of RDD (two nodal sites and two extranodal upper respiratory tract sites) were analysed for parvovirus B19 (B19) infection by immunohistochemistry to detect B19 capsid proteins VP1/VP2. In all the four cases, huge numbers of B19-positive cells were partly detected. The positive cells were identified either as lymphocytes or, in one extranodal case, also as respiratory epithelial cells. This is the first report of B19 infection in RDD tissue, indicating that B19 may be associated with the pathogenesis of SHML.

AM-3K, an anti-macrophage antibody, recognizes CD163, a molecule associated with an anti-inflammatory macrophage phenotype

CD163 is a member of the scavenger receptor cysteine-rich superfamily restricted to the monocyte/macrophage lineage and is thought to be a useful marker for anti-inflammatory or alternatively activated macrophages. In this study we used mass spectrometric analysis to determine that the antigen recognized by the antibody AM-3K, which we previously generated as a tissue macrophage-specific monoclonal antibody, was CD163. An anti-inflammatory subtype of macrophages stimulated by dexamethasone or interleukin-10 showed strong reactivity for AM-3K and increased expression of CD163 mRNA. Immunohistochemical staining of routinely processed pathological specimens revealed that AM-3K recognized a specialized subpopulation of macrophages. In granulomatous diseases such as tuberculosis, sarcoidosis, or foreign body reactions, tissue macrophages around granulomas, but not component cells of the granulomas such as epithelioid cells and multinucleated giant cells, showed positive staining for AM-3K. In atherosclerotic lesions, scattered macrophages in diffuse intimal lesions were strongly positive for AM-3K, whereas foamy macrophages in atheromatous plaques demonstrated only weak staining. We therefore suggest that, in routine pathological specimens, AM-3K is a useful marker for anti-inflammatory macrophages because these cells can be distinguished from inflammatory or classically activated macrophages. Because AM-3K cross-reacts with macrophage subpopulations in different animal species including rats, guinea pigs, rabbits, cats, dogs, goats, pigs, bovine species, horses, monkeys, and cetaceans, it will have wide application for detection of CD163 in various animals.

Minimal change nephropathy in a 7-year-old boy with Rosai-Dorfman disease

Rosai-Dorfman (R-D) disease is a benign lympho-histiocytosis of the lymphoid system. Immune derangement due to cytokine over-expression (tumor necrosis factor (TNF), interleukin (IL)-1b and IL-6) has been considered the cause of R-D disease. We present a 7-year-old boy with R-D disease who developed minimal change nephropathy (MCN) during the progression of R-D disease. The patient was resistant to oral prednisolone; and the remission of both R-D disease and MCN was achieved with oral cyclophosphamide (2 mg/kg, 12 weeks). MCN, the most common cause of nephrotic syndrome in childhood, is generally accepted to emerge by way of cytokine derangement. Correlation between R-D disease activity and the development and remission of nephrotic syndrome in our case suggested that nephrotic syndrome had been induced through some R-D disease-related immune mechanisms.

Clinical and histopathologic spectrum of cutaneous Rosai-Dorfman disease in Taiwan

BACKGROUND

Cutaneous Rosai-Dorfman disease (RDD) is a rare entity of unknown origin and is not well documented, especially in Asian populations.

OBJECTIVE

The purpose of this study was to evaluate the clinical manifestation, diagnostic histopathology, clinical course, and response to treatment of cutaneous RDD in Taiwan.

MATERIALS AND METHODS

This study included 21 patients with cutaneous RDD who presented at our institution from 1995 to 2003. Pathologic examinations with both hematoxylin-eosin and immunohistochemical stains were reviewed, as were associated clinical features and therapeutic methods.

RESULTS

None of the 21 patients with cutaneous RDD had nodal lesions. The clinical manifestation was variable, but most commonly involved a central noduloplaque with satellite papules. One patient manifested as an ulcerated nodule, something not reported previously. Multifocal involvement only occurred in 4 patients. Concurrent involvement of uvea or vocal cord occurred in two patients. The most prominent histologic feature was a florid and mixed inflammatory infiltration. The phagocytosis of inflammatory cells into the cytoplasm of histiocytes, a process called "emperipolesis," is a characteristic finding of nodular RDD but usually only focally presented in cutaneous ones. Positivity for S-100 protein helped to confirm the diagnosis. The most effective treatment was surgical excision of solitary lesions. High-dose thalidomide (300 mg/d), but not low-dose, was effective to control the extensive cutaneous diseases in two patients. A total of 3 patients experienced spontaneous remission 1 to 2 years after diagnosis.

CONCLUSIONS

Cutaneous RDD appeared more frequently in Asian populations than in reports from Western countries. The incidence of multifocal involvement in this series is much lower than in other literature. Although treatment of disseminated cutaneous RDD is difficult, high-dose thalidomide (300 mg/d), which was effective in two patients in this series, may be helpful.

["Catastrophic systemic lupus erythematosus" with Rosai-Dorfman sinus histiocytosis. Successful treatment with anti-CD20/rutuximab]

HISTORY AND ADMISSION FINDINGS

A 59-year old woman was admitted with a four-month history of polyarthritis, myalgias and photosensitivity insufficiently responsive to methotrexate, corticosteroids and azathioprin. On physical examination she presented with symmetric ankle edema, polyserositis, petechial bleeding and swelling of cervical, axillary and inguinal lymph nodes.

INVESTIGATIONS

Laboratory analysis revealed a trilinear cytopenia without signs of hemolysis. Acute phase proteins were elevated. Furthermore antinuclear antibodies, anti-phospholipid IgM antibodies, hypocomplementemia, a spurious IgGkappa paraprotein were noted. CT scans confirmed lymphadenopathy and revealed a pleural and pericardial effusion. Bone marrow biopsy showed marked hypercellularity and polyclonal plasmocytosis. Based on these findings systemic lupus erythematosus was initially suspected. However when abdominal MRI showed a retroperitoneal mass, an extensive histological workup, which also included lymph nodes and spleen, revealed numerous plasma cells and histiocytes in dilated sinuses, diagnostic of Rosai-Dorfman sinus histiocytosis.

TREATMENT AND COURSE

High dose corticosteroids, intravenous gamma-globulin and repeated courses of cyclophosphamide failed to improve the pancytopenia, as did splenectomy. The patient was given the anti-CD20 monoclonal antibody Rituximab and all signs and symptoms improved dramatically. 18 months after the last treatment, the patient is in complete clinical and hematological remission.

CONCLUSIONS

Sinus histiocytosis of Rosai/Dorfman can be associated with or mimic severe SLE. Rituximab, an anti-CD20 monoclonal antibody, may improve the antibody-mediated pathogenetic mechanism underlying both entities.

Cutaneous sinus histiocytosis and chronic uveitis

Sinus histiocytosis with massive lymphadenitis or Rosai-Dorfman disease (RDD) is a rare, benign, proliferative histiocytic disease of unknown origin. It predominately affects the lymph nodes The skin is the extranodal organ most frequently involved, although a few patients present with only lesions of the skin and soft tissues, without involvement of the lymph nodes (purely cutaneous RDD). Ocular involvement is rare, and generally localized to the eyelid. We report an unusual case of cutaneous sinus histiocytosis without nodal involvement and with bilateral uveitis in a girl. As far as we know, this is the first case reported in which cutaneous and ocular RDD occurred without nodal involvement.

Regulation of T lymphocyte trafficking into lymph nodes during an immune response by the chemokines macrophage inflammatory protein (MIP)-1 alpha and MIP-1 beta

By virtue of their target cell specificity, chemokines have the potential to selectively recruit leukocyte subpopulations into sites of inflammation. Their role in regulation of T lymphocyte traffic into lymph nodes during the development of an immune response has not previously been explored. The sensitization phase of contact hypersensitivity induced by the hapten, dinitrofluorobenzene (DNFB) in the mouse was used as a model of T lymphocyte trafficking in response to antigenic stimulation. Rapid accumulation of CD8+ and CD4+ T cells in the draining lymph nodes was closely associated with strongly enhanced expression of macrophage inflammatory protein (MIP)-1 alpha and MIP-1 beta mRNAs and proteins. Mast cells accumulating in the nodes during DNFB sensitization were the predominant source of MIP-1 beta, whereas MIP-1 alpha was expressed by multiple cell types. Neutralization of these chemokines profoundly inhibited T lymphocyte trafficking into lymph nodes and altered the outcome of a subsequent challenge to DNFB. Thus, beta-chemokines regulate T lymphocyte emigration from the circulation into lymph nodes during an immune response and contribute significantly to the immunologic outcome.

Isolated intracranial involvement in Rosai-Dorfman disease: a report of two cases and review of the literature

Rosai-Dorfman disease is an idiopathic histiocytic disorder of lymph nodes and extranodal sites. Central nervous system manifestations of this disease are rare, and to our knowledge only 16 cases of intracranial involvement have been reported previously. Intracranial Rosai-Dorfman disease clinically and radiologically resembles meningioma, and histologic examination is essential for a definitive diagnosis. We report two cases of isolated, intracranial, dural-based Rosai-Dorfman disease, review the literature, and discuss the differential diagnoses of this lesion.

Extranodal Rosai-Dorfman disease in childhood

We describe two children with Rosai-Dorfman disease who presented with exophthalmos, leukocytosis, an elevated sedimentation rate and hypergammaglobulinemia. Both became blind as a result of this condition. One child had associated bilateral cervical lymphadenopathy. Investigation revealed involvement of the nasal fossae and retro-orbital spaces by tumoural masses histologically consistent with the diagnosis of sinus histiocytosis with massive lymphadenopathy (SHML). Immunohistochemical studies suggest that these histiocytes are activated macrophages derived from a phenotype hybrid between "professional" phagocytic cells and immune accessory cells, expressing lysosomal antigens, S-100 protein but rarely, CDla. An underlying immune dysfunction may be central to the pathogenesis of this disease.

Monokine expression in Langerhans' cell histiocytosis and sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease)

Langerhans' cell histiocytosis (LCH) is a clonal proliferation of Langerhans cells (LC) showing histologically an abundant reactive infiltrate composed of macrophages and lymphocytes, as well as eosinophilic and neutrophilic granulocytes. Rosai-Dorfman disease (RDD) shows a sinusoidal accumulation of large histiocytic cells with an immunophenotype similar to LC of LCH. The histological picture of LCH is reminiscent of an inflammatory disorder and LC may produce cytokines and are influenced by these soluble factors. This study set out to establish the monokine expression pattern in LCH in comparison with those of RDD; dermatopathic lymphadenopathy, which also shows a proliferation of S100-positive dendritic cells; and LC in normal skin specimens. Isotopic in situ hybridization was used for the detection of transcripts of tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and IL-1 beta, in some cases combined with immunohistology for the S100 protein or CD68. In all 11 tissue samples from eight patients, LC of LCH expressed TNF-alpha; in two cases IL-1 beta transcripts were additionally noted in some LC, whereas IL-6 was found in reactive cells. Large histiocytic cells of RDD expressed all three monokines, whereas minimal or no expression of these cytokines could be detected in interdigitating reticulum cells in dermatopathic lymphadenopathy. In two out of five normal skin samples, only TNF-alpha specific signals were observed in LC. These data suggest that histologically different lesions of the histiocytic/dendritic cell system display distinct cytokine profiles. The expression of monokines, which have been demonstrated to influence various functions of epidermal LC, may play a role in the pathogenesis of LCH. Systemic symptoms in RDD may be related to enhanced production of monokines in these lesions.

Sinus histiocytosis with massive lymphoadenopathy (Rosai-Dorfman disease). Clinico-pathological analysis of a paediatric case

Histochemical and immunohistochemical studies performed in only a few cases of sinus histiocytosis with massive lymphoadenopathy (SHML) indicated that SHML cells belong to the macrophage--histiocyte system, though their exact origin is still uncertain. We analyzed the morphological, antigenic and enzymatic characteristics of the histiocyte-like cells in one paediatric case of SHML (also named Rosai-Dorfman disease). The SHML cells expressed the S-100 protein, lectins concanavalin A, peanut agglutinin and monocyte-macrophage related antigens CD 11c, CD 14, CD 33, CD 68 and LN 5. Reactivity with other anti-macrophage antibodies (MAC387, lysozyme, alpha-1 anti-chymotrypsin) was variable. The CD1a antigen was present only in scattered cells, whereas HLA-DR and the HLA-DR associated invariant chain were absent. Cytochemistry demonstrated an intense activity of acid phosphatase and non specific esterase of SHML cells. A large amount of medium sized mononuclear cells were located in the sinuses and intersinusoidal tissue. Our findings suggest that SHML cells have intermediate features between phagocytes and Langerhans cells/interdigitating reticulum cells. The heterogeneity of marker expression on SHML cells might be related to the local content of factors (e.g., cytokines), capable of modulating the phenotype of monocyted and derived cells.

Sinus histiocytosis with massive lymphadenopathy: a spectrum of disease associated with immune dysfunction

A detailed immunologic study of three cases of sinus histiocytosis with massive lymphadenopathy (SHML) was performed to better characterize this rare disorder. One patient had prominent cervical lymphadenopathy that regressed spontaneously, whereas the other two patients had persistent cervical lymphadenopathy and recurrent infections. The first patient was otherwise healthy and had normal immunologic studies. One of the latter patients had a relative increase in blood B cells, a decreased level of serum immunoglobulin A (IgA), decreased blood lymphocyte mitogenic responses to multiple mitogens (37-42% of controls), and cutaneous anergy. The other patient with persistent disease also had a relative increase in blood B cells, polyclonal hypergammaglobulinemia, and circulating immune complexes, as well as decreased blood T cells and markedly decreased blood lymphocyte responses to mitogens (12-37% of controls). Immunohistochemical stains of the lymph nodes of the three patients revealed a characteristic phenotype for the sinus histiocytes: S-100 protein, 3/3; CD14 (Leu M3) 3/3; CD11c (Leu M5), 1/1; CD71 (OKT9), 3/3; CD4 (Leu 3a), 2/3; CD1a (OKT6), 1/3; alpha-1-antitrypsin, 3/3; alpha-1-antichymotrypsin, 3/3; CD35 (C3b), 1/1; CD11b (Mo1), 0/3; CD15 (Leu M1), 0/3; HLA-DR, 0/3; and lysozyme, 0/3. This phenotype suggests that the cells of SHML have features of both the Langerhans/interdigitating cell and mononuclear phagocyte lineages. Emperipolesis by the histiocytes of B cells, T cells, and natural killer cells was demonstrated by a double-staining technique. Our findings indicate that patients with SHML may have a variably expressed immunodeficiency that predisposes them to recurrent infections.

Immunophenotypic characterization of sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease)

Histochemical and immunohistochemical studies have been reported in only a few cases of sinus histiocytosis with massive lymphadenopathy (SHML) to date. These indicate that SHML cells belong to the macrophage/histiocyte family, but their exact origin is still unknown. We determined the antigenic phenotype of SHML cells in sections from 20 cases of routinely fixed, paraffin-embedded tissue and from two cases of fresh frozen tissue using a broad panel of antibodies to macrophage/histocyte, B-, and T-cell antigens. SHML cells expressed the following: (1) S-100 protein, (2) "pan-macrophage" antigens such as EBM11, HAM 56, and Leu-M3, (3) antigens functionally associated with phagocytosis (Fc receptor for IgG, complement receptor 3), and lysosomal activity (lysozyme, alpha 1-antichymotrypsin, and alpha 1-antitrypsyn), (4) antigens associated with early inflammation (Mac-387, 27E10), (5) antigens commonly found on monocytes, but not tissue macrophages (OKM5, Leu-M1), and (6) "activation" antigens (Ki-1 and receptors for transferrin and interleukin 2). These data suggest that SHML cells are true functionally activated macrophages that may be recently derived from circulating monocytes.

[Skin involvement in Rosai-Dorfman disease. Description of a case]

Sinus Histiocytosis with massive lymphadenopathy is an idiopathic, histologically distinctive disorder that characteristically produces painless cervical lymphadenopathy. Other node groups are frequently involved and mass lesions in extranodal sites occur in approximately 30% of patients. In most cases the disease is chronic and the course is often characterized by exacerbations and remission. We report the case of a 66 years old white woman affected by sinus histiocytosis with massive cervical and inguinal lymphadenopathy. Subcutaneous nodules appeared in her left arm and low back region with the histological features of sinus histiocytosis. Cellular infiltrate was composed predominantly of histiocytes aggregating in granuloma like clusters. These cells had large round or kidney shaped nuclei; cytoplasm was abundant, vacuolated, often containing phagocytized lymphocytes. Multinucleated cells were also observed; reactive plasmocytosis was present in the nodule periphery. During the follow-up the patient maintained good physical conditions, despite a moderate weight loss. The size of her nodules regressed within one year. Immunologic alterations, consisting of polyclonal hypergammaglobulinemia and persistent inversion of T4/T8 lymphocyte ratio, were observed. Sinus histiocytosis usually offers a good prognosis; in our patient infective and/or autoimmune complications could be favoured by advanced age, extranodal involvement and immunological depression.