Multicentric reticulohistiocytosis and cancer: a case report and review of the literature

Multicentric Reticulohistiocytosis Associated with an Early Form of Systemic Lupus Erythematosus: A Case Report of a Rare Disease, with Mini Review of the Literature

Multicentric reticulohistiocytosis (MRH) is the most frequently described form of reticulohistiocytosis (RH), and it is classified as a class IIb non-Langerhans cell histiocytosis. It has been designated as multicentric, being characterized by multisystemic involvement. In fact, although mainly involving the skin, along with the joints, it is a systemic inflammatory condition potentially involving every internal organ. As MRH-related skin findings can mimic rheumatoid nodules or Gottron papules, the histopathology of the cutaneous lesions is often necessary for the correct diagnosis. Approximately one-third of MRH patients have confirmed concomitant autoimmune disorders. A wide variety of autoimmune disorders associated with the disease have been reported in the literature, suggesting immune dysfunction as a factor in the pathophysiology of MRH. A case of MRH associated with autoimmune manifestation is reported in the context of a mini review of the literature, with a focus on clinical presentation, treatments, and treatment outcomes. Moreover, eight cases of MRH associated with autoimmune diseases are briefly discussed.

Reticulohistiocytoses: a revision of the full spectrum

Reticulohistiocytoses (RH) are rare and clinically heterogeneous histiocytic disorders of dermatological interest. Three clinical entities with superimposable histopathological features are currently considered, namely solitary reticulohistiocytoma, diffuse/generalized reticulohistiocytosis and multicentric reticulohistiocytosis. Although in the last decade, RH studies have only minimally progressed, histiocytosis research has advanced considerably: the prognostic and therapeutic importance of the clinical subclassification of histiocytosis patients as well as of the detection of genetic alterations in the genes of the ERK pathway has been highlighted. According to these insights, we previously reported the presence of molecular alteration RH and described a subset of patients with disseminated multisystem involvement lacking arthritis. In the present review, we aim to update and revise the knowledge regarding RH. We first reviewed their histopathological, immunophenotypical and ultrastructural features, discussed their histopathological differential diagnosis with other conditions characterized by infiltrates made of oncocytic or epithelioid cells (with special regard to Destombes-Rosai-Dorfman disease) and finally summarized the molecular landscape of RH. We therefore tried to adjust the clinical subclassification of Langerhans cell histiocytosis to the clinical phenotypes of RH, outlining five clinically different groups of patients. Finally, we reconsidered the clinical workflow to the evaluation of RH patients, in light of the 5 different clinical groups and discussed the different therapeutic approaches and the possible role of target inhibitors.

Cutaneous paraneoplastic disorders in stomach cancer: Collaboration between oncologically active dermatologists and clinical oncologists

To our knowledge this is the first systemic review that provides an overview of the cutaneous paraneoplastic syndromes (CPS) (i.e., clinical manifestations, pathomechanisms, and treatment modalities) occurring in stomach cancer. CPS are caused by substances produced by stomach cancer and may precede, coincide with, or follow the diagnosis of this malignancy. More than 20 possible CPS in association with stomach cancer have been identified. CPS mostly compromises the patient's quality of life by skin impairment plus discomfort and are often associated with a dismal prognosis on survival. Studies of these CPS not only in stomach cancer have partially contributed to the understanding of pathomechanism and since CPS may be the presenting sign of an occult cancer, cognizance of their features and clinical implications are of considerable importance. Patients with these syndromes should have an appropriate work-up for a possibly occult malignancy with consecutive successful early treatment.

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.

A Case of Multicentric Reticulohistiocytosis Misdiagnosed as Rheumatoid Arthritis

<p>Multicentric reticulohistiocytosis (MRH) is a rare disease characterized by nodular skin lesions and severe erosive polyarthritis which is associated with malignancy in some cases. The diagnosis is confirmed by the presence of oncocytic histiocytes and multinucleated giant cells on histopathology of the cutaneous nodules and the synovial membrane. It usually remits spontaneously after 5-8 years but it can provoke destructive arthritis. We report a case of a 49-year-old female who presented with numerous nodules on the both hands, face and abdomen and progressive destructive polyarthritis of 3 years duration and has been diagnosed with rheumatoid arthritis. The lesion showed large histiocytes with ground-glass eosinophilic cytoplasm, typical of MRH. Clinical manifestation and radiological pattern of MRH may be misdiagnosed as other disease like rheumatoid arthritis and psoriatic arthritis, but histopathologic findings of our case can differentiate MRH from any other conditions.</p>

Multicentric reticulohistiocytosis with elevated cytokine serum levels

Multicentric reticulohistiocytosis (MRH) is an uncommon non-Langerhans cell histiocytosis of unknown etiology. It is a multisystem disorder characterised by a papulonodular skin eruption, mainly in the extensor surfaces, and destructive polyarthritis. Histologically, either cutaneous lesions or the synovium show a dense dermal infiltrate of histiocytes and multinucleated giant cells with an eosinophilic granular material in the cytoplasm. In the immunohistochemical analysis these cells stain positively with monocyte/macrophage markers (CD68 and CD45), as well as with certain cytokines (tumor necrosis factor-α, interleukin 1β and interleukin 6). Moreover, recent reports suggest an osteoclastic nature of the infiltrating cells, as they stain strongly with osteoclast tissue lytic markers including tartrate-resistant acid phosphatase and cathepsin K. We report a case of MRH presenting with clinical features of dermatomyositis. Furthermore, the patient showed elevated cytokine serum levels that lowered after therapy.

Facial papules as a marker of internal malignancy

Facial papules (bumps) confront the general practitioner during every face-to-face meeting with the patient. Increased awareness and recognition of the facial papules that represent cutaneous signs of internal malignancy will allow an early, aggressive workup and treatment of any associated cancer. This article details the clinical presentation, etiology, pathologic findings, and associated malignancy for such presentations. A skin biopsy for histopathologic diagnosis is necessary to distinguish these clues to underlying malignancy from the numerous benign lesions that cause facial papules.

Multicentric reticulohistiocytosis associated with ovarian cancer

Multicentric reticulohistiocytosis (MR) is an uncommon disease characterized by joint and cutaneous manifestations. The diagnosis must be confirmed by histological evidence of typical histiocytes and multinucleated giant cells. Many conditions, including malignancy, have been described in association with MR. We herein report a female case of MR in whom partial improvement was obtained by steroid and low-dose methotrexate treatments. However, ovarian cancer was found and therefore a surgical resection and chemotherapy were performed. These treatments resulted in the complete resolution of the skin and joint symptoms. These findings support the close linkage between MR and malignancy and the efficacy of cytotoxic drugs for the treatment of MR.

Multicentric reticulohistiocytosis: a proliferation of macrophages with tropism for skin and joints, part II

In this second part of the review of multicentric reticulohistiocytosis, the authors discuss its association with other diseases, in particular, cancer, and laboratory and therapeutic aspects of this incapacitating and disfiguring disease. Histopathologic aspects are characteristic: dense mononuclear infiltrate with typical multinucleated cells that contain periodic acid-Schiff-positive and diastasis-resistant material, conferring a "ground glass" aspect when stained with hematoxylineosin.

Aggressive histiocytic disorders that can involve the skin

Histiocytoses are a heterogeneous group of disorders that are characterized by the proliferation and accumulation of reactive or neoplastic histiocytes. Three classes of histiocytoses have been defined: class I, Langerhans cell disease; class II, non-Langerhans cell histiocytic disease without features of malignancy; and class III, malignant histiocytic disorders. Although the disorders in classes I and II usually have a benign appearance on histology and are commonly non-aggressive and self-healing, some can cause debilitating or even fatal outcomes. Such cases beg the question: what stimulates aggressive behavior of a classically benign disease? New molecular information may now provide insight into the driving force behind many of the aggressive histiocytoses. In this article, we review Langerhans cell disease and seven aggressive histiocytoses that can involve skin, discuss histologic features that may forecast a poor prognosis, and discuss the molecular findings that help to explain the pathophysiology of these aggressive histiocytic disorders.

[Diffuse cutaneous reticulohistiocytosis]

The reticulohistiocytoses make up a heterogeneous group of diseases whose origin lies in an accumulation of cells of histiocytic lineage in different tissues and primarily in the skin. Three main clinical forms have been described (multicentric, solitary, diffuse cutaneous), which present with identical histological, ultrastructural and immunohistochemical characteristics. We present a case of diffuse cutaneous reticulohistiocytosis, which is the least common clinical pattern in the spectrum of this disease.

Proliferating multicentric reticulohistiocytosis associated with papillary serous carcinoma of the endometrium

Multicentric reticulohistiocytosis (MRH) is a rare histocytic disease characterized by destructive arthritis in association with classic skin findings. Although MRH is not strictly a paraneoplastic disease, one quarter of cases are malignancy related. We report a case of MRH with an initial remission followed by an acute exacerbation several years later heralding the clinical presentation of endometrial carcinoma. During this flareup a skin biopsy specimen revealed a diffuse dermal infiltrate composed of histiocytes with ground-glass cytoplasm and multiple atypical mitoses. Approximately 40% of the cells stained with the proliferation marker Ki-67. Treatment of endometrial carcinoma resulted in improvement of skin and joint symptoms, and a repeat biopsy specimen no longer demonstrated mitotic figures. These findings support a reactive and proliferative cause of MRH.

Multicentric reticulohistiocytosis with generalized systemic involvement

We describe a 33-year-old woman with a 2-year history of rheumatoid arthritis-like joint changes and a 1-year history of papulonodules on the fingers, ears, oral mucosa, forearm, elbows and thighs, and erythematous plaques on the buttocks. Six months after the onset of the cutaneous lesions she had dyspnoea, 3 months later she developed a husky sound. Biopsies from the nodules on the ear and left forearm revealed multinucleated giant cells with eosinophilic 'ground-glass' cytoplasm. Bronchoscopy revealed that there were nodules in the bronchus. A biopsy taken from a nodule from the bronchus was consistent with multicentric reticulohistiocytosis. Fibrostic laryngoscopy showed a mass 1.5 x 2.0 cm(2) in size on the left aryepiglottic fold and posterior commissure. Magnetic resonance imaging revealed a large pleural effusion and pericardiac effusion. Ultrasound revealed splenomegaly and peritoneal fluid. Combination therapy with prednisone, cyclophosphamide and methotrexate significantly improved cutaneous and joint symptoms. The huge cutaneous erythematous plaques and the generalized systemic involvement make this case interesting.

Multicentric reticulohistiocytosis in a 14-year-old girl

Multicentric reticulohistiocytosis is a rare multisystem disorder in which an infiltration of histiocytic cells causes papulonodular skin lesions and potentially a destructive polyarthritis. The active disease typically resolves spontaneously after 5-8 years, but the articular destruction can lead to permanent joint deformities. We present a case of multicentric reticulohistiocytosis in a 14-year-old girl. The number of papules on her hands decreased in number and her arthritic symptoms improved after 4 months of oral naproxen. Thirty months later her joint symptoms remained inactive and only six very small papules remained on her hands. Small flexor deformities were present in the distal interphalangeal joints of both index fingers. This case is an example of how multicentric reticulohistiocytosis can be a relatively stable and self-limited disease but still cause permanent joint deformities.

Multicentric reticulohistiocytosis

BACKGROUND

Multicentric reticulohistiocytosis (MR) is a rare histiocytic systemic disease mainly affecting the skin and synovia.

OBJECTIVE

To present the main and newest aspects of MR.

METHOD

A review of the current medical literature, composing a retrospective study of 96 case reports published world-wide since 1977.

RESULTS

Facial and hand skin nodules with symmetric arthritis were the most frequent clinical presentation. The pathognomonic sign of'coral beads' and vermicular erythematous lesions bordering nostrils, seems to be very characteristic of MR. There is a significant association with cancer. Histiocytic cells of MR are best characterized on immunohistochemistry by its immunoreactivity for vimentin, CD68 and CD45 and non-reactivity for S-100 protein, CD34 and factor XIIIa. Although the outcome of the disease is usually very limiting for the patients, treatment with immunosuppressive drugs may be useful.

CONCLUSION

MR is a unique histiocytic proliferative disease with a peculiar immunophenotypic pattern and distinctive clinical and histopathological aspects.

Paraneoplastic rheumatic syndromes

Malignant neoplasms are associated with a wide variety of paraneoplastic rheumatological syndromes. Among these, hypertrophic osteoarthropathy, carcinoma polyarthritis, dermatomyositis/polymyositis, and paraneoplastic vasculitis are the most frequently recognized. Other less known associations are based upon a smaller number of reported patients, and include fasciitis, panniculitis, erythema nodosum, Raynaud's syndrome, digital gangrene, erythromelalgia and lupus-like syndromes. Musculoskeletal manifestations of malignancy may coincide, follow or antedate the diagnosis of cancer, or herald its recurrence. The clinical course generally parallels that of the primary tumour, and treatment of the underlying malignancy often results in regression of the rheumatic disorder. Awareness that cancer can cause certain non-metastatic symptoms is important for early diagnosis and treatment of an occult neoplasm. Rheumatic manifestations suggesting a hidden cancer include: rapid onset of an unusual inflammatory arthritis clubbing or diffuse bone pains in a patient 50 years of age or older, chronic unexplained vasculitis, refractory fasciitis, Raynaud's syndrome unresponsive to vasodilator therapy, rapidly progressive digital gangrene or Lambert-Eaton myasthenic syndrome. Management consists of control of the underlying cancer and symptomatic treatment of the rheumatic syndrome with non-steroidal anti-inflammatory drugs or corticosteroids.

Multicentric reticulohistiocytosis in a child

A case of multicentric reticulohistiocytosis in an 8-year-old girl, which is a diagnosis rarely seen in children, is presented. Multicentric reticulohistiocytosis is a disorder of unknown aetiology, predominantly affecting the joints, skin and mucosa. Joint symptoms, but not cutaneous lesions, have improved with treatment with methotrexate.

Gingival lesions in a patient with dermochondrocorneal dystrophy (François syndrome). A case report

This report is concerned with gingival manifestations associated with a case of dermochondrocorneal dystrophy (DCCD) or François syndrome occurring in a 42-year-old woman. Our Department treated this patient for 15 years. Oral examination of this case revealed a diffuse enlargement and severe inflammation of the attached gingiva. Systemic findings were similar to those reported in the literature for patients with DCCD. Firm papules 3 mm wide, localized on the face and on the dorsal surface of the hands, were associated with corneal involvement and progressive and severe articular disorder. Because they recurred after surgical ablation, the gingival lesions became an important problem in the management of the patient. After 10 years of unsuccessful treatment limited to scaling, oral hygiene control and mouth rinses with 0.2% chlorexidine solution, the patient was submitted to extraction of the remaining teeth, remodelling osteoplasty and cutaneous graft. An acrylic full denture was inserted. In a follow-up of 7 years, good results for the oral health of the patient were seen.

Multicentric reticulohistiocytosis associated with recurrent breast carcinoma

Multicentric reticulohistiocytosis (MRH) is a rare systemic disorder that most often affects women in the fourth to fifth decades of life and is characterized by widespread cutaneous papules and nodules, often associated with a destructive arthritis. The characteristic histologic feature of the skin lesions, and of other affected organs, is the presence of histiocytes and multinucleated giant cells containing abundant eosinophilic cytoplasm with a "ground glass appearance." Approximately 30% of the patients have an underlying malignancy suggesting MRH may be a paraneoplastic phenomenon. We describe a case of MRH associated with recurrent, metastatic breast carcinoma.

Methotrexate use in miscellaneous inflammatory diseases

Methotrexate has proven to be a safe, effective, long-term therapy for rheumatoid arthritis. Its property as a corticosteroid-sparing drug in rheumatoid arthritis has been recognized and its potential has been explored in other inflammatory and autoimmune diseases. This article describes and analyzes the use of methotrexate for a wide variety of diseases, some of which are not the usual province of rheumatologists, to provide some guidance concerning its role for treatment. Methotrexate therapy seems promising for systemic lupus erythematosus, inflammatory myopathy, inflammatory eye disease, inflammatory bowel disease, and some manifestations of sarcoidosis. Its role in other diseases is not as well defined.

A case of multicentric reticulohistiocytosis, systemic sclerosis and Sjögren syndrome

We report the case of a 42-year-old Japanese woman who developed multicentric reticulohistiocytosis (MR) complicated by systemic sclerosis (SSc) and Sjögren syndrome (SS). The patient complained of tender nodules on the left hand, polyarthralgia in the finger joints and knees, and xerostomia. The skin nodules were distributed mainly on her hands and fingers with skin sclerosis. The serum anti-nuclear test revealed anti-centromere antibody and the discrete speckled pattern of anti-nuclear antibody. The biopsy specimens from the finger nodule and the sclerotic finger skin showed a perivascular infiltration of multinucleated giant cells with ground-glass cytoplasm and dermal thick collagen proliferation, respectively. The lip biopsy and sialography specimens showed periductal lymphocyte infiltration and apple tree-like changes. Systemic corticosteroid treatment improved the polyarthritis, xerostomia, and skin sclerosis rapidly but suppressed the nodular lesions only gradually. This is the first report of a combined case of MR, SSc and SS. This multiple autoimmune complication suggests the involvement of an immunological disturbance in the pathogenesis of MR.

Complete remission of multicentric reticulohistiocytosis with combination therapy of steroid, cyclophosphamide, and low-dose pulse methotrexate. Case report, review of the literature, and proposal for treatment

We describe a patient with multicentric reticulohistiocytosis in whom complete remission was achieved by sequential combination therapy with steroid, methotrexate, and cyclophosphamide. We reviewed all cases of complete or near-complete remissions of multicentric reticulohistiocytosis reported in the English-language literature and propose a new drug regimen for this rare but potentially disabling disease.

Cutaneous paraneoplastic syndromes in solid tumors

OBJECTIVE

To provide an overview of the clinical manifestations, pathophysiology, and oncologic implications of the cutaneous paraneoplastic syndromes that occur predominantly in patients with solid tumors.

METHODS

A review was performed of the literature identified by a comprehensive MEDLINE search.

RESULTS

Diverse cutaneous paraneoplastic syndromes may be associated with underlying tumors. They include musculoskeletal disorders (clubbing, hypertrophic osteoarthropathy, dermatomyositis, and multicentric reticulohistiocytosis), reactive erythemas (erythema gyratum repens and necrolytic migratory erythema), vascular dermatoses (Trousseau's syndrome), papulosquamous disorders (acanthosis nigricans, tripe palms, palmar hyperkeratosis, acquired ichthyosis, pityriasis rotunda, Bazex's syndrome, florid cutaneous papillomatosis, the sign of Leser-Trélat, and extramammary Paget's disease), and disorders of hair growth (hypertrichosis lanuginosa acquisita). The clinical manifestations of these dermatoses may precede, coincide with, or follow the diagnosis of cancer. The presence of a cutaneous paraneoplastic syndrome is often associated with a poor prognosis.

CONCLUSIONS

Cutaneous paraneoplastic syndromes are specific constellations of mucous membrane and/or skin abnormalities that are caused by an underlying tumor. Since they may be the presenting sign of an occult cancer, cognizance of their features and clinical implications are of considerable importance. Individuals with these syndromes should have a thorough workup for an associated malignancy.

Malignancy-associated multicentric reticulohistiocytosis: a clinical, histological and immunophenotypic study

The clinical, histopathological, and immunophenotypic characteristics of four cases of malignancy-associated multicentric reticulohistiocytosis (MMR) and one case each of diffuse cutaneous reticulohistiocytosis (DCR) and isolated reticulohistiocytoma (IR), are reviewed. In all four cases of MMR the cutaneous lesions and joint manifestations were judged to be concurrent with the diagnosis of malignancy. Malignancies observed included one case each of pancreatic adenocarcinoma, squamous cell carcinoma of the lung, metastatic melanoma and intraperitoneal grade 4 mucinous adenocarcinoma of uncertain origin. Histologically, all six cases demonstrated the typical changes of a diffuse histiocytic and multinucleated giant cell infiltrate with ground-glass cytoplasm, predominantly in the upper dermis. Immunohistochemical investigation revealed strong cytoplasmic staining with KP-1 (CD68) in all six cases. Prominent membrane staining was noted with leucocyte common antigen (CD45) in four cases (three MMR and one IR), and CD3 in four cases (three MMR and one IR). Weak membrane staining with Leu 22 (CD43) was noted in two MMR cases. UCHL-1 (CD45RO), L26 (CD20), S-100 and BerH2 stains were all uniformly negative. A prominent number of perilesional factor XIIIa-positive dermal dendrocytes were noted in the single case of IR, in contrast with the other five cases. We conclude that MMR, DCR and IR are histopathologically and immunohistochemically similar. The pattern of immunoreactivity observed is consistent with a monocyte-macrophage origin of the infiltrating tumour cells. We emphasize the paraneoplastic association of multicentric reticulohistiocytosis, which we have observed in four of 13 such cases (31%) evaluated at our institution.

Eyelid involvement in multicentric reticulohistiocytosis

CASE REPORT

The authors report the first biopsy-confirmed ocular adnexal involvement by multicentric reticulohistiocytosis. The patient was a 28-year-old black woman with a 15-year history of well-documented multicentric reticulohistiocytosis who had multiple dermal nodules and severe mutilating arthritis that had produced a characteristic telescoping deformity of the digits. Eyelid nodules were excised to relieve pseudoptosis and for cosmesis.

MATERIALS

The eyelid nodules were studied by routine light microscopy and a battery of immunohistochemical stains, including S-100 protein and several macrophage markers.

RESULTS

Microscopy disclosed an infiltrate of histiocytes and giant cells with glassy eosinophilic cytoplasm and large round or oval vesicular nuclei with prominent nucleoli set in a densely fibrotic stroma consistent with multicentric reticulohistiocytosis. The histiocytes showed positive immunoreactivity for lysozyme, but were negative for alpha-1 antichymotrypsin, S-100 protein, and neuron-specific enolase.

CONCLUSION

Multicentric reticulohistiocytosis should be included in the differential diagnosis of multiple eyelid nodules.

Radiologic case study. Multicentric reticulohistiocytosis

MRH is somewhat similar to, and probably occasionally mistaken for, psoriatic arthritis, Reiter's syndrome, or less frequently, rheumatoid arthritis. However, several important features distinguish MRH from the other arthritides. Rheumatoid arthritis more commonly involves the metacarpophalangeal joints, while MRH ordinarily affects the distal interphalangeal and proximal interphalangeal joints. Furthermore, MRH rarely exhibits the degree of articular osteopenia that is the hallmark of rheumatoid disease. While psoriatic arthritis and Reiter's often affect the DIP joints, they rarely display the symmetry of MRH. In addition, MRH does not demonstrate the periosteal new bone formation that is seen in both psoriatic arthritis and Reiter's syndrome. Hence, the diagnosis of MRH may be made with reasonable confidence on the radiologic findings alone, even before the cutaneous nodules appear, which can then be biopsied to confirm the diagnosis.

Multicentric reticulohistiocytosis with arthritis and cardiac infiltration: regression following treatment for underlying malignancy

The case is reported of a 63 year old man presenting with a rapidly destructive symmetrical polyarthritis and widespread papular nodular skin lesions, confirmed by a biopsy to be due to multicentric reticulohistiocytosis. Biventricular cardiac failure developed secondary to extensive myocardial infiltration with multicentric reticulohistiocytosis, a complication of this disease which has not previously been reported. The joint, skin, and cardiac manifestations of multicentric reticulohistiocytosis substantially regressed following resection of an associated squamous cell carcinoma. This report adds to the small amount of published work which suggests that multicentric reticulohistiocytosis can be a paraneoplastic disease that may respond to treatment directed at the underlying tumour.

Multicentric reticulohistiocytosis: systemic macrophage disorder

Multicentric reticulohistiocytosis is a rare multisystem disorder that reflects a reactive inflammatory response to an undetermined stimulus. While the disease is characterized as a dermatoarthritis, multiple organ systems including cardiac and skeletal muscle, the pleura and gastrointestinal tract have been involved in reported cases. The synovitis can be quite destructive with arthritis mutilans developing in a substantial percentage. The dermatitis may be particularly disfiguring when the face is involved. This chapter describes the clinical and laboratory features of the 33 cases of MRH previously reviewed by Barrow and Holubar and an additional 33 cases that have appeared in the medical literature since that report. We note an apparent decline in frequency of some manifestations of MRH. This may be due in part to the nature of the recent reports which often present a brief clinical report and focus primarily on specific disease associations, unusual manifestations, new organ system involvement or treatment regimens. The primary cell involved in the reactive inflammatory response of MRH is the phagocytic tissue histiocyte (macrophage). While uncontrolled proliferation of these reticulohistiocytes is seen in several infectious and malignant conditions there is presently no direct evidence of a particular organism or neoplasm involved in the aetiopathogenesis of MRH. There is evidence of tuberculosis exposure in one third of cases with active tuberculosis present in 5%. Likewise, malignancies are reported concomitantly with MRH in 15-28% of cases. The therapeutic trend in MRH is to treat early and aggressively to prevent the devastating arthropathy and disfiguring cutaneous sequelae. This recommendation, however, is largely based on anecdotal reports and thus the physician encountering a case of MRH needs to proceed with circumspection.

Multicentric reticulohistiocytosis in a patient with malignant melanoma: a response to cyclophosphamide and a unique cutaneous feature

We describe a patient with multicentric reticulohistiocytosis and a history of malignant melanoma. His widely disseminated disease did not affect the site of surgical removal of the malignant melanoma nor the donor site of a skin graft. The multicentric reticulohistiocytosis progressed while the patient was taking nonsteroidal antiinflammatory agents, but showed significant response during a 10-month course of cyclophosphamide. While he was taking the cyclophosphamide, however, his melanoma recurred, and the patient subsequently died.

Reticulohistiocytoma cutis--review of 15 cases and an association with systemic vasculitis in two cases

We reviewed 15 cases of reticulohistiocytoma cutis (RHC). Three cases were of solitary lesions. Four cases were associated with a destructive arthritis but no other systemic features. One additional patient had a destructive arthritis and lesions of reticulohistiocytoma in synovium, larynx, and mucosa. Three patients had associated xanthelasma. Two cases were associated with internal malignancy (metastatic malignant melanoma, adenocarcinoma of the bowel). Two cases were sequentially associated with systemic vasculitis (Wegener's granulomatosis, periarteritis nodosa). This occurrence of systemic vasculitis in RHC patients is unique. RHC may have variable cutaneous and systemic manifestations and associations with malignancy and immunoinflammatory diseases, including vasculitis.