Multicentric reticulohistiocytosis

A case report of multicentric reticulohistiocytosis with atypical cutaneous presentation

Multicentric reticulohistiocytosis (MRH) is a rare systemic disorder characterized by histiocytic hyperplasia that mainly involves the skin, mucous membranes, and joints. The typical clinical features include papules, nodules, and arthritis. MRH lesions are relatively extensive but small and scattered. Joint inflammation is characterized by diffuse symmetric polyarthritis as the first symptom, which can be severe and disabling due to destructive joint changes. MRH is easily misdiagnosed in clinical practice. Here, we report the case of an elderly male patient who presented with polyarticular pain in the hip and interphalangeal joints as the first manifestation, followed by the development of large, isolated, bulging skin nodules, which are atypical MRH lesions. This is rare in all MRH case reports, and we made the correct diagnosis by combining skin histopathology, immunohistochemistry, and other clinical examinations. We performed surgical treatment on the local skin lesions of this patient. This case suggests that clinicians should actively correlate the condition and accurately diagnose MRH when encountering atypical skin changes or other diseases as the first symptom and explore the mechanisms of MRH and other clinical manifestations.

Identification and characterization of stromal-like cells with CD207+/low CD1a+/low phenotype derived from histiocytic lesions - a perspective in vitro model for drug testing

BACKGROUND

Histiocytoses are rare disorders manifested by increased proliferation of pathogenic myeloid cells sharing histological features with macrophages or dendritic cells and accumulating in various organs, i.a., bone and skin. Pre-clinical in vitro models that could be used to determine molecular pathways of the disease are limited, hence research on histiocytoses is challenging. The current study compares cytophysiological features of progenitor, stromal-like cells derived from histiocytic lesions (sl-pHCs) of three pediatric patients with different histiocytoses types and outcomes. The characterized cells may find potential applications in drug testing.

METHODS

Molecular phenotype of the cells, i.e. expression of CD1a and CD207 (langerin), was determined using flow cytometry. Cytogenetic analysis included GTG-banded metaphases and microarray (aCGH) evaluation. Furthermore, the morphology and ultrastructure of cells were evaluated using a confocal and scanning electron microscope. The microphotographs from the confocal imaging were used to reconstruct the mitochondrial network and its morphology. Basic cytophysiological parameters, such as viability, mitochondrial activity, and proliferation, were analyzed using multiple cellular assays, including Annexin V/7-AAD staining, mitopotential analysis, BrdU test, clonogenicity analysis, and distribution of cells within the cell cycle. Biomarkers potentially associated with histiocytoses progression were determined using RT-qPCR at mRNA, miRNA and lncRNA levels. Intracellular accumulation of histiocytosis-specific proteins was detected with Western blot. Cytotoxicyty and IC50 of vemurafenib and trametinib were determined with MTS assay.

RESULTS

Obtained cellular models, i.e. RAB-1, HAN-1, and CHR-1, are heterogenic in terms of molecular phenotype and morphology. The cells express CD1a/CD207 markers characteristic for dendritic cells, but also show intracellular accumulation of markers characteristic for cells of mesenchymal origin, i.e. vimentin (VIM) and osteopontin (OPN). In subsequent cultures, cells remain viable and metabolically active, and the mitochondrial network is well developed, with some distinctive morphotypes noted in each cell line. Cell-specific transcriptome profile was noted, providing information on potential new biomarkers (non-coding RNAs) with diagnostic and prognostic features. The cells showed different sensitivity to vemurafenib and trametinib.

CONCLUSION

Obtained and characterized cellular models of stromal-like cells derived from histiocytic lesions can be used for studies on histiocytosis biology and drug testing.

Multicentric reticulohistiocytosis: A diagnostic challenge

Multicentric reticulohistiocytosis, also called as lipoid dermato-arthritis is a rare form of non-Langerhans cell histiocytosis characterised by nodular and papular skin lesions containing characteristic bizarre multinucleate giant cells with ground glass cytoplasm. The disease commonly involves the skin, mucosa, synovium, and internal organs with cutaneous nodules and progressive erosive arthritis being the most common presenting features. We report a case of a 61-year-old male presenting with multiple swellings over distal part of fingers for 6 years without involvement of joints. A diagnosis of multicentric histiocytosis was made based on typical histopathological features of sheets of histiocytes and multinucleate giant cells with ground glass eosinophilic cytoplasm. The disease has a low incidence and about 300 cases have been reported so far in literature. The present case is being reported as it is uncommon for the disease to present in absence of arthritis.

Clinical characteristics of multicentric reticulohistiocytosis and distinguished features from rheumatoid arthritis: a single-center experience in China

OBJECTIVE

To investigate the clinical features of multicentric reticulohistiocytosis (MRH).

METHODS

The clinical manifestations, laboratory examination results and histologic characteristics of eleven patients with MRH were collected and compared with those of 33 patients with rheumatoid arthritis.

RESULTS

In total, 72.7% of the MRH patients were women. The median age was 46 years (range 33-84 years). Diagnosed by specific pathologic features, all MRH patients exhibited cutaneous involvement. The dorsa of the hands, arms, face and auricle were the most commonly affected areas. Nodules were also located on the legs, scalp, trunk, neck, and even the hypoglossis and buccal mucosa. Ten MRH patients (90.9%) had symmetric polyarthritis. Compared with rheumatoid arthritis (RA) patients, MRH patients were more likely to have distal interphalangeal joint (DIP) involvement (63.6% vs 24.2%, P = 0.017) and less likely to have elbow (36.4% vs 72.7%, P = 0.003), ankle (45.5% vs 93.9%, P < 0.001) and metacarpophalangeal joint (MCP) (36.4% vs 78.8%, P = 0.009) involvement. Positivity for rheumatoid factor (RF) (36.4% vs 84.6%, P = 0.001) and anti-CCP antibody (9.1% vs 81.8%, P = 0.000), as well as the median RF titer [43.8 (31.7-61.0) vs 175.4 (21.3-940.3), P = 0.021], in MRH patients was lower than in RA patients. Elevation of the erythrocyte sedimentation rate (ESR) was also less common in MRH patients than in RA patients (36.4% vs 72.7%, P = 0.030). After treatment with median- to large-dose corticosteroids and disease-modifying antirheumatic drugs, 8 patients achieved complete remission and 2 patients partial remission (skin lesions ameliorated, joint lesions not ameliorated).

CONCLUSION

Always pathologically diagnosed, MRH is a systemic disease involving RA-like erosive polyarthritis and a specific distribution of skin nodules characterized by "coral beads". More DIP involvement and less elbow, ankle and MCP involvement are seen in MRH than in RA. In addition, less positivity and lower-titer RF, uncommon presence of anti-CCP antibodies and ESR elevation may be helpful to distinguish MRH from RA.

Skin Manifestation Associated With Multicentric Reticulohistiocytosis

ABSTRACT

Multicentric reticulohistiocytosis (MRH) is a rare multisystem disorder, primarily affecting the skin and joints. As severe joint damage is a possible symptom, early diagnosis and therapeutic intervention are required. Cutaneous lesions present with characteristic features such as discrete reddish nodules, especially on acral locations. Additionally, the face, scalp, trunk and extremities are also affected. Xanthomatous plaques are also seen on the face. The cutaneous manifestations of MRH are various, which therefore should be differentiated from several diseases. In particular, MRH has been reported to assume clinical appearances resembling Gottron papules, periungual erythema, V-neck erythema, shawl sign, and poikiloderma associated with dermatomyositis. Histopathologic features show proliferation of multinucleated giant cells with abundant eosinophilic granular ground glass-like cytoplasm in the dermis. Multicentric reticulohistiocytosis is occasionally paraneoplastic and is associated with internal malignancies. The appropriate therapies are still challenging, and oral prednisolone, immunosuppressants, and recent biologics are used. In this article, cutaneous lesions, histopathology, and pathogenesis of MRH are mainly discussed from a dermatological perspective. It is important, not only for dermatologists but also for rheumatologists and orthopedists, to be able to distinguish between the various types of skin lesions brought on by MRH. Cutaneous signs are important diagnostic clues and assessment tools for therapeutic efficacy.

[Multicentric reticulohistiocytosis: A case report]

A 65-year-old woman developed erythema, papules and nodules over the body. Some nodules of her auricles and hands like string beads. Besides, she suffered from symmetrical swelling and pain of multiple joints, morning stiffness with deformity of joints; She had elevated erythrocyte sedimentation rate and C reactive protein levels; Her rheumatoid factor and antinuclear antibody were positive; Joints destruction was found with X-ray imaging; Skin pathology showed Dermal infiltrate of abundant histiocytes, part of them with a ground-glass appearance; A CD68 immunohistochemical stain was positive and the cells were negative for S100, CD1a. These findings were diagnostic evidences of multicentric reticulohistiocytosis (MRH). The patient received high-dose of glucocorticoids combinated with immunosuppressive agents, and achieved a satisfactory effect. MRH was a rare multisystem disease characterized by papulonodular mucocutaneous and destructive arthritis, and its pathogeny was not yet completely understood. The typical lesions of MRH were hard papules or nodules that usually occured on the hands, face and arms. Classic coral bead appearance from periungual cutaneous nodules that were characteristic of MRH. MRH was an inflammatory joint disease, affecting almost all the appendicular joints and characterized by joint multiple, symmetrical, destructive, progressive disability. Joints destruction of the distal interphalangeal joints was a unique feature of MRH. In addition to skin and joints, it could also involve other systems. There were no diagnostic laboratory markers for MRH. Laboratory examinations had often been found to be non-specific. Imageological examination mainly showed bone and joint destruction. Skin biopsy was the best test to diagnose MRH, the typical histopathological findings included an infiltrate with histiocytes and multinucleated giant cells with a ground-glass appearing in eosinophilic cytoplasm, and the immunohistochemical stain was positive for CD68. The diagnosis was typically made based on the clinical presentation, supportive radiographic findings and skin biopsy. MRH was easily possible to mistake for other more common autoimmune conditions, such as rheumatoid arthritis, psoriatic arthritis, osteoarthritis, and dermatomyositis, but the distinctive clinical, radiographic, and histologic features could aid in differentiating these diseases. MRH could mimic other rheumatic diseases, besides, it could also coexist with cancer or other autoimmune disorders. There was no standardized treatment for MRH. However, Nonsteroidal anti-inflammatory drugs, glucocorticoid, Immunosuppressant, biologic medications, and bisphosphonates had been used with varying degrees of curative effect. Treatment with glucocorticoid combined with immunosuppressants were effective for rash and arthritis, early use of them should be strongly considered, and refractory cases could be treated with biological agents. By reporting a MRH case and reviewing literature, this paper aims to help the clinicians improve the understanding of this rare disease, and suggests that when one diagnosis cannot explain the whole picture of the disease, and further evidence should be sought to confirm the diagnosis.

Progressive Nodular Histiocytosis: Report of a Case and Review of the Literature

Progressive nodular histiocytosis (PNH) is a rare condition characterized by progressive eruption of multiple yellowish-brown papules and nodules on the skin and mucous membranes. We present the case of a 37-year-old Caucasian man with gradually increased appearance of nodular lesions on the forehead and right temple. These lesions were initially diagnosed as xanthomas and did not respond to intralesional injections of triamcinolone. Additional biopsy revealed an intense dermal infiltrate of foamy mononuclear epithelioid cells with a minor admixture of plasma cells, lymphocytes, and scattered multinucleated giant cells. On immunohistochemical staining, the lesional cells were positive for CD163 and CD68 and negative for CD1a, thus confirming a mononuclear-macrophage lineage. The clinical presentation and the histological impression lead to the diagnosis of PNH. This condition could be challenging, mimicking microscopically similar lesions of the non-Langerhans cell histiocytosis group. Although uncommon, PNH stands out due to its clinical and microscopic features and should be taken into consideration in the differential diagnosis of cutaneous histiocytoses.

Multicentric reticulohistiocytosis: the Mayo Clinic experience (1980–2017)

Objectives

Multicentric reticulohistiocytosis (MRH), a rare histiocytic disease that can mimic other rheumatic conditions, may be associated with cancer and other autoimmune disorders. To better understand the disorder and its other associations, we aimed to evaluate clinical correlates and outcomes of all patients with MRH seen at Mayo Clinic, Rochester between 1980 and 2017.

Methods

A retrospective medical record review was conducted to identify all patients with MRH between 1 January 1980 and 30 April 2017.

Results

We identified 24 patients with biopsy-proven MRH (58% female, 75% Caucasian, median age at diagnosis 52 years, median follow-up of 2.3 years). All patients had cutaneous and articular involvement; 23 (96%) patients had papulonodular skin lesions (87% periungual and dorsal hand) and seven (30%) mucosal nodules; and 22 (92%) patients had arthralgias, 21 (88%) joint effusions and 13 (54%) synovitis. Most frequently used therapies included corticosteroids, cyclophosphamide, methotrexate and bisphosphonates. Biologics were used in four patients. Nine patients had symptomatic resolution at 1 year and 12 partial improvement. Radiological findings included erosive changes in three (60%) patients and arthritis mutilans in two patients (40%). Twenty-nine per cent of patients had a concomitant autoimmune disease and 25% malignancy including melanoma, endometrial, peritoneal and lung carcinoma. The 5-year survival rate was 85% (95% CI: 74, 100%).

Conclusion

To our knowledge, this is the largest single-centre series of patients with MRH highlighting the rarity of the condition and an unmet need for treatment options that can allow sustained disease remission. It also highlights the need for a high vigilance for malignancy and autoimmune diseases.

A Rare Case of Multicentric Reticulohistiocytosis with Concurrent Rheumatoid Arthritis

Multicentric reticulohistiocytosis (MRH) is a rare multisystem macrophage disorder of unknown etiology characterized by papulonodular skin and mucosal lesions, rapidly progressive erosive symmetric polyarthritis, and inflammation of internal organs. Most often, it is misdiagnosed as rheumatoid arthritis (RA). Here, we report the case of a 60-year-old woman found to have features of both MRH and RA with positive rheumatoid factor and high titer of anti-cyclic citrullinated peptide antibody in serum. It was confirmed by a histopathology of skin lesions, which showed diffuse histiocytic infiltrate with multinucleated giant cells. She was treated with methotrexate, hydroxychloroquine, corticosteroids, and nonsteroidal anti-inflammatory drugs and bisphosphonate.

Cutaneous paraneoplastic syndromes

A variety of cutaneous abnormalities can be seen in patients with malignant diseases, some of which are infectious, with others representing direct involvement of the skin by the underlying disorder. Yet another group of lesions can be regarded as associated markers of the malignant process, and, as such, are termed "paraneoplastic." This review considers the latter collection of conditions, grouping them by the generic type of malignancy that is usually linked to the paraneoplasia. Some of the processes show a predominant association with alimentary tract malignancies (acanthosis nigricans, acrodermatitis paraneoplastica, florid cutaneous papillomatosis, necrolytic migratory erythema, palmoplantar keratoderma, pancreatic fat necrosis, and pityriasis rotunda). Others are usually linked to a hematolymphoid malignancy (acquired ichthyosis, exfoliative erythroderma, necrobiotic xanthogranuloma, pemphigus paraneoplastica, plane xanthoma, pyoderma gangrenosum, scleromyxedema, Sweet syndrome, and leukocytoclastic vasculitis). Finally, yet another collection of paraneoplastic skin disorders can associate themselves with anatomically-diverse malignancies (Leser-Trelat syndrome, Trousseau syndrome, dermatomyositis, erythema gyratum repens, hypertrichosis lanuginosa acquisita, papuloerythroderma of Ofuji, tripe palms, and multicentric reticulohistiocytosis). Recognition of these processes by the pathologist can be a valuable step in the characterization of underlying malignant diseases.

Thalidomide, A Rational Agent for Treatment of Multicentric Reticulohistiocytosis

A patient with Multifocal Reticulohistiocytosis (MRH) of skin and joints failed treatment with etanercept, methotrexate, hydroxychloroquine, prednisone, bisphosphonates and hydroxyzine. Long term treatment with thalidomide led to marked improvement in joint and cutaneous manifestations.

The clinical spectrum of xanthomatous lesions of the eyelids

Yellowish papules, nodules, or plaques, namely "xanthomatous" lesions, may be seen on the eyelids in the course of various disorders. The prototype is "xanthelasma palpebrarum" (XP) that is localized only to the eyelids and may be associated with hyperlipidemia. On the other hand, different types of normolipemic disorders may also cause xanthomatous eyelid lesions. Among these, Langerhans cell histiocytosis, diffuse normolipemic xanthoma, and non-Langerhans cell histiocytoses (papular xanthoma, juvenile xanthogranuloma, xanthoma disseminatum, adult-onset xanthogranuloma, adult-onset asthma and periocular xanthogranuloma, necrobiotic xanthogranuloma, Erdheim-Chester disease, Rosai-Dorfman disease, and reticulohistiocytosis) can be listed. The eyelid findings of this heterogeneous group of disorders are challenging to differentiate from each other due to common clinical aspects that may even sometimes mimic XP. Nodularity, induration, ulceration, diffuse eyelid involvement, and extension from eyelids to the neighboring skin may represent the clinical features of xanthomatous lesions other than XP. It is necessary to obtain a thorough history and exclude XP and then perform detailed dermatological and systemic examination, biopsy for histopathologic confirmation, and appropriate specific imaging screens. As some of the conditions may be associated with other systemic disorders, especially malignancies, the differentiation of xanthomatous eyelid lesions has a critical importance, and clinical signs can be guiding.

Clonal reticulohistiocytosis of the skin and bone marrow associated with systemic mastocytosis and acute myeloid leukaemia

AIMS

The aims of this study were to define whether diffuse cutaneous reticulohistiocytosis could be underpinned by somatic genetic alterations and represent a precursor of more aggressive forms of disease.

METHODS AND RESULTS

A 59-year-old man with diffuse cutaneous reticulohistiocytosis experienced bone marrow localization of the disease, with associated systemic mastocytosis and acute myeloid leukaemia. Cytogenetic analyses of the bone marrow aspirate revealed the presence of a derivative chromosome giving rise to a partial trisomy of chromosome 1q and a partial monosomy of chromosome 9q. Therefore, we characterized the cutaneous lesions before and after chemotherapy by using an integrative approach combining histopathology, electron microscopy, and fluorescence in-situ hybridization. Histologically, the skin lesions belonged to the spectrum of diffuse cutaneous reticulohistiocytoses, as confirmed by immunohistochemistry and ultrastructural analyses. Fluorescence in-situ hybridization in the skin nodules confirmed the presence of the genetic alterations previously detected in the bone marrow.

CONCLUSIONS

Here, we provide circumstantial evidence to suggest that at least a subset of cutaneous reticulohistiocytoses harbour clonal molecular alterations. Furthermore, we confirm that these lesions have the potential to arise in the setting of concurrent haematological disorders. In this hypothesis-generating study, two possible tumorigenesis models are proposed.

Efficacy of Vinblastine and Prednisone in Multicentric Reticulohistiocytosis With Onset in Infancy

Multicentric reticulohistiocytosis (MRH) is a rare histiocytic proliferative disorder of uncertain etiology, characterized by mucocutaneous papulonodular lesions and progressive, symmetric erosive arthritis. MRH can coexist with various autoimmune disorders, tuberculosis, and malignancy. It usually occurs in the elderly and is very rare in children. This is probably the first case in which disease manifestation appeared in infancy in the form of skin lesions. The patient had recurrent ulceration of cutaneous lesions, which is unusual in MRH. Early diagnosis and aggressive treatment are essential to prevent progressive irreversible course and development of arthritis mutilans. Various drugs, such as steroids, nonsteroidal anti-inflammatory drugs, immunosuppressants, interleukin inhibitors, and tumor necrosis factor-α antagonist, have been tried with variable responses. The present case responded well to vinblastine and steroid, which have not been reported previously. Here, we document a case of MRH with early onset in infancy along with role of vinblastine and prednisone in its treatment.

Multiple Cutaneous Reticulohistiocytoma

Multicentric reticulohistiocytosis is a rare non-Langerhans cell histiocytosis characterized in its full form by severe destructive arthritis, cutaneous nodules, and systemic manifestations. Cutaneous lesions may precede, accompany, or more commonly develop later than other features in this disease. We describe a case of multiple cutaneous reticulohistiocytoma without any systemic associations after thorough investigations.

Multicentric reticulohistiocytosis (MRH): case report with review of literature between 1991 and 2014 with in depth analysis of various treatment regimens and outcomes

Multicentric reticulohistiocytosis is a rare disease affecting skin and joints primarily and rarely other organs. We present a case report of this disease and an extensive review of the literature. We reviewed the data between 1991 and 2014 and extracted 52 individual cases. Only articles in English were chosen after checking for relevance. The articles were studies and data was extracted into excel spread sheets and later used to compute such variables like frequency, mean and percentage of distribution of various clinical manifestations. The treatments used in these articles were critically analyzed and graded for their relative efficacy for skin and joint manifestations. The grades were 0 = worse, 1 = no benefit/condition remained same, 2 = improvement without resolution, and 3 = resolution. This article also reports the demographic, clinical, laboratory and pathological data from the reviewed articles. Authors attempted to discuss the findings of this review in depth to help manage this condition and proposed a treatment algorithm to help clinicians approach this rare and challenging disease.

Multicentric reticulohistiocytosis: a case report of an atypical presentation in a 2-year-old

Multicentric reticulohistiocytosis (MRH) is a rare systemic inflammatory granulomatous disease marked by severe and often rapidly progressive polyarticular arthritis and cutaneous papulonodules. Initial clinical diagnosis may be difficult. We describe a 2-year-old girl presenting with pink dermal papules on the forehead, thighs, elbows, knees, and palms of the hands. Based on clinical findings and skin biopsy results, she was initially diagnosed with granuloma annulare. At 5 years of age, she developed arthritis, fatigue, and more widespread skin papules leading to the diagnosis of MRH. To our knowledge, this is the youngest individual with MRH yet described. We outline the timeline and unique features of her case and review the literature pertaining to MRH in children. Although rare, MRH can be permanently debilitating, making prompt diagnosis critical. A standardized approach to investigation and management needs to be developed.

A case of multicentric reticulohistiocytosis

Multicentric reticulohistiocytosis (MRH) is a rare non-Langerhans histiocytosis of unknown etiology with a predilection for joint and skin. The characteristic clinical features are papulonodular skin eruptions and inflammatory polyarthritis, sometimes progressive to arthritis mutilans, a severe destructive arthropathy. Although these manifestations can present at the same time, it is more common that one feature precedes the others. Notably, these features are similar to those found in some rheumatic diseases, such as rheumatoid arthritis or dermatomyositis, and this can lead to a misdiagnosis, especially during periods where only one feature is present. Herein, we report a female patient with polyarthralgia and subsequent skin eruptions, who was eventually diagnosed with MRH. Her symptoms seemed to resemble those of some rheumatic diseases, but several features such as affected joints and the characteristic shape of the skin lesions did not correspond to that. The histological result of infiltration of histiocytes and multinucleated giant cells in the skin ultimately facilitated the correct diagnosis. In this paper, we review MRH briefly and highlight several differential points which enable us to increase the likelihood of correctly diagnosing MRH.

New described dermatological disorders

Many advances in dermatology have been made in recent years. In the present review article, newly described disorders from the last six years are presented in detail. We divided these reports into different sections, including syndromes, autoinflammatory diseases, tumors, and unclassified disease. Syndromes included are “circumferential skin creases Kunze type” and “unusual type of pachyonychia congenita or a new syndrome”; autoinflammatory diseases include “chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature (CANDLE) syndrome,” “pyoderma gangrenosum, acne, and hidradenitis suppurativa (PASH) syndrome,” and “pyogenic arthritis, pyoderma gangrenosum, acne, and hidradenitis suppurativa (PAPASH) syndrome”; tumors include “acquired reactive digital fibroma,” “onychocytic matricoma and onychocytic carcinoma,” “infundibulocystic nail bed squamous cell carcinoma,” and “acral histiocytic nodules”; unclassified disorders include “saurian papulosis,” “symmetrical acrokeratoderma,” “confetti-like macular atrophy,” and “skin spicules,” “erythema papulosa semicircularis recidivans.”

Multiple Reticulohistiocytomas in an 88-year-old Man: a Case Report

Solitary and multiple reticulohistiocytomas, often referred to as diffuse cutaneous reticulohistiocytosis, that are generally restricted to skin, must be differentiated from multicentric reticulohistiocytosis. Multicentric reticulohistiocytosis is a rare histiocytic proliferative disease affecting joints, skin and mucous membranes, while arthropathy usually precedes skin and mucosal involvement. Other organs may also be involved, and 20% of patients have an associated internal malignancy. Multicentric reticulohistiocytosis has been reported to be associated with autoimmune diseases and malignancies. We present an 88-year-old man, with a sudden eruption of asymptomatic, firm, skin to brown colored papules and nodules, 6 to 17 mm in diameter, localized on forehead, arms, legs, and buttocks. There were no symptoms of joint or other organ involvement. Clinical and dermoscopic characteristics pointed to reticulohystiocytomas. Multiple excision biopsies of different tumors were performed and histopathology reports confirmed the diagnosis. In the case presented, reticulohistiocytosis was limited to the skin, exhibiting multiple reticlohistiocytomas with typical clinical, dermoscopic and rather peculiar histopathology presentation. Apart from this, some histologic features were seen in early lesions of multicentric reticulohistiocytosis, such as multinuclear cells dissociating collagen fibers with pale eosinophilic and foamy cytoplasm. Besides surgical excisions, no other treatment options were done. Laboratory and other tests showed no presence of extracutaneous illness, and no autoimmune or paraneoplastic processes. At one year follow up, the remaining tumors were of the same size, but there were no recurrences at excision sites, no signs of disease progression or systemic involvement. Since diffuse cutaneous reticulohistiocytosis without arthropathy as well as isolated reticulohistiocytomas have been described, in some cases of multiple reticulohistiocytomas even without systemic symptoms and signs, multicentric reticulohistiocytosis should be considered with an appropriate follow up. In such cases, skin lesions have the same histological features as lesions in multicentric reticulohistiocytosis, but they are not associated with joint problems or neoplasms.

Multicentric reticulohistiocytosis presenting with papulonodular skin lesions and arthritis mutilans

Multicentric reticulohistiocytosis is a rare multisystem disorder of unknown etiology that is characterized by erosive polyarthritis and papulonodular lesions on the skin, mucous membranes, and internal organs. We report the case of a 54-year-old female who was misdiagnosed as having rheumatoid arthritis and underwent numerous joint replacement surgeries for progressively destructive arthritis in her hands, shoulders, hips, and knees. The patient finally received a diagnosis of multicentric reticulohistiocytosis after histopathological examination of the patient's left knee arthroplasty which revealed a diffuse histiocytic infiltrate, multinucleated giant cells, and finely granulated eosinophilic cytoplasm with a ground-glass appearance.

Multicentric reticulohistiocytosis and fibroblastic rheumatism

Multicentric reticulohistiocytosis (MRH) and fibroblastic rheumatism (FR) are uncommon disorders with similar joint and skin manifestations. They are usually included among the non-Langerhans histiocytoses, but recent insights drive some criticism. The diagnosis is often challenging and must be confirmed by the histological typical features. If the skin manifestations are missing, the arthritic complaints may be confused with those of other rheumatic disorders. In these cases, only a careful clinical and radiological evaluation leads to the correct diagnosis. The natural course of the diseases may rapidly develop into disabling manifestations, making an aggressive treatment strongly recommendable. There is emerging evidence that anti-tumour necrosis factor-α agents and bisphosphonates are promising drugs for MRH, while a course of methotrexate and steroids seems to be the best option for FR. Finally, the clinician should be aware that in many cases MRH, but not FR, is associated with a large number of systemic manifestations and with malignancy. This eventuality must be accurately ruled out.

Multicentric reticulohistiocytosis associated with liver carcinoma: report of a case

We report a unique case of multicentric reticulohistiocytosis (MRH) associated with liver carcinoma. A 61-year-old man presented with a 4-month history of nonpruritic, generalized, ruby-red papules and nodules, accompanied by fever, joint swelling and difficulty in swallowing. Skin histology showed polymorphic histiocyte infiltration with typical 'ground glass' cytoplasm. Further immunohistochemical studies characterized the lesions as positive for leukocyte common antigen, HLA-DR and CD68. The patient had a history of hepatitis B, and systemic examination, including carcinoma index and type-B ultrasonic examination, revealed high levels of AFP and a solid tumor, which was considered malignant, localized on the right lobe of the liver. Treatment of the liver carcinoma resulted in a significant improvement of the skin symptoms. This is the first case study to report an association between MRH and liver carcinoma. A review of the English-language literature reveals the close linkage between MRH and malignancy. All patients with MRH should be evaluated and monitored carefully to determine the underlying neoplasm.

Neoplastic/paraneoplastic dermatitis, fasciitis, and panniculitis

The skin changes outlined in this article can be important clues to an underlying malignancy. Paraneoplastic dermatoses are skin disorders associated with an underlying neoplasm and whose course parallels that of the neoplasm. Recognizing these skin presentations leads to early diagnosis and management of the underlying malignancy. Effective treatment of the associated neoplasm often leads to improvement of the cutaneous manifestations and should be the primary focus of each patient's management.