Paraneoplastic rheumatic syndromes

Advances of autoimmune rheumatic diseases related to malignant tumors

BACKGROUND

Malignant neoplasms are a well-recognized global public health concern, with significant impacts on human health and quality of life. The interplay between tumors and autoimmune rheumatic diseases is complex, and the resulting tumor-associated rheumatic diseases represent a rare and intricate group of conditions that occur in the context of malignant tumors. In addition, various rheumatic diseases can arise as a consequence of oncology treatment. These diseases present with intricate clinical manifestations and pathological features, often rendering them challenging to diagnose and impacting patients' quality of life. Despite this, they have yet to be fully recognized.

METHODS

This article presents a literature review of published original articles and review articles concerning paraneoplastic rheumatic syndromes and rheumatic diseases associated with cancer treatment. We conducted a comprehensive literature search in PubMed, Web of Science and Google Scholar databases, excluding duplicated and irrelevant studies. In cases of duplicated research, we selected articles with higher impact factors for the review.

RESULTS

This review focuses on the clinical features, diagnosis, and treatment of paraneoplastic rheumatic diseases, as well as the pathogenesis of these diseases. Additionally, we summarize the autoimmune rheumatic diseases associated with cancer treatment. Ultimately, the goal of this review is to enhance recognition and improve the management of autoimmune rheumatic diseases related to tumors.

Cardiac sarcoma presenting as paraneoplastic arthritis and clubbing: a case report and literature review

BACKGROUND

Cardiac tumours are rare, and clinical manifestations depend on the anatomical location. Symptoms can be the result of cardiac outflow anomalies, constitutional features such as fever, loss of weight, and/or paraneoplastic manifestations such as arthritis. To date, there has only been one other case report in the literature of cardiac sarcoma presenting as paraneoplastic arthropathy.

CASE PRESENTATION

A 52-year-old woman presented with acute onset corticosteroid-resistant inflammatory polyarthralgia, clubbing and a systolic murmur. Transthoracic echocardiogram revealed a dilated left atrium with an echogenic mass and brain magnetic resonance imaging revealed multiple embolic infarcts. Histopathology following emergency resection showed a Grade 3 left atrial intimal sarcoma. The polyarthralgia and clubbing resolved soon after tumour removal. The patient went on to receive chemotherapy and remains in remission.

CONCLUSIONS

This case highlights the rare paraneoplastic association of cardiac sarcoma and arthropathy.

Update on Malignancy in Myositis—Well-Established Association with Unmet Needs

Idiopathic inflammatory myopathies are a group of rare connective tissue diseases with a well-documented association with malignancy. The mechanisms underlying the increased risk of neoplasms in the course of myositis are not fully understood. The Pubmed database has been thoroughly screened for articles concerning cancer-associated myositis (CAM). The article summarizes the current state of knowledge on the epidemiology and pathogenesis of CAM. Furthermore, it analyses potential risk and protective factors for developing CAM, with particular emphasis on the association with distinct serological profiles. The review summarizes recommendations proposed so far for the management of CAM and presents a novel scheme for cancer screening proposed by the authors. Moreover, promising areas requiring further research were indicated.

Myeloid disorders after autoimmune disease

Autoimmune diseases (ADs) are associated with an increased risk not only of lymphoproliferative disorders but also of myeloid malignancies. The excess risk of myelodysplastic syndromes and/or acute myeloid leukemia is observed across several AD types, including systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disorders, multiple sclerosis, among others. The risk of developing myeloid neoplasms (MNs) is dependent on several variables, including the specific AD type, chronicity and severity of the AD, type and duration of exposure of disease modifying anti-rheumatic drugs or cytotoxics/immunosuppressives, and genetic predisposition risk. Putative triggering factors linking AD to elevated MN risk include AD-directed medications, shared genetic susceptibilities between the two disease entities, and chronic immune stimulation or bone marrow infiltration by the AD. Molecular mechanisms underpinning leukemogenesis remain largely speculative and warrant further investigation. Leukemias arising in patients with AD are not always 'therapy-related' in that MNs may develop in certain AD subtypes even among patients with no prior therapy exposure. Only a few studies have attempted to determine factors associated with MN development in AD but failed to demonstrate consistent characteristic clinical or paraclinical features. These reports have failed to demonstrate a clear correlation between individual agent exposure and subsequent leukemia development due to the low rates of therapy exposure compounded by the rarity of MN occurrence. Notwithstanding, the leukemogenic potential is best documented with agents such as azathioprine, cyclophosphamide, and mitoxantrone; this risk of MN development does not appear to be shared by biologic approaches such as anti-tumor necrosis factors-alpha inhibitors. In this article, we discuss plausible biologic mechanisms underlying MN pathogenesis in AD and review the data available on the development of MNs in patients with AD.

Risks of hepatocellular carcinoma and cirrhosis-associated complications in patients with rheumatoid arthritis: a 10-year population-based cohort study in Taiwan

BACKGROUND/PURPOSE

Although rheumatoid arthritis (RA) has been linked to several important malignancies, data for the risks of hepatocellular carcinoma (HCC) in patients with RA are scarce. We aimed to examine the risk of HCC and cirrhosis-associated complications and the use of biologics in a national representative RA sample in Taiwan.

METHODS

All study subjects aged ≥ 18 years in the Taiwan National Health Insurance program between January 1, 2000, and December 31, 2009 were enrolled. We matched RA and non-RA subjects by propensity scores in a 1:1 ratio. Our primary outcome was a diagnosis of HCC and cirrhosis-associated complications during a 10-year follow-up period. The risk of outcomes was represented as a hazard ratio (HR) calculated in Cox proportional hazard regression models.

RESULTS

24,245 RA and 24,245 non-RA subjects were included in the primary outcome analysis. Mean overall person-years (PY) of follow-up were 116,608 PY for the RA cohort, and 234,280 PY for the non-RA cohort. The overall incidence of HCC and cirrhosis-associated complications was lower in the RA cohort than in the non-RA cohort (0.66% vs. 1.41% HCC events and 1.45% vs. 1.95% cirrhosis-associated complications events during 10-year follow-up). The HRs adjusted for age, sex, the frequency of medical visits, and CCI were 0.57 (0.46-0.71) for HCC and 0.67 (0.59-0.76) for HCC and cirrhosis-associated complications. Although immunomodulatory agents may alter the risk of malignancy, use of biologics did not increase HCC risk in RA patients.

CONCLUSIONS

RA is associated with a reduced risk of developing HCC and cirrhosis-associated complications.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02880306.

Occult renal cell carcinoma presenting as carcinomatous polyarthritis

Carcinomatous polyarthritis (CP) is a rare paraneoplastic disorder which can be associated with various solid tumors and can even precede detection of the underlying malignancy. A 54-year-old male presented with migratory asymmetric inflammatory polyarthritis and high-grade fever for 6 months. On evaluation, he was diagnosed to have renal cell carcinoma (RCC). CP as an initial presentation of RCC was not described previously.

Autoimmune Phenomena in Patients with Solid Tumors

INTRODUCTION

Autoimmune disorders have been documented in solid tumors and malignant hematological disorders. They are very common and well studied in lymphomas which are associated with immune imbalance. They are less common in solid tumors and are categorized as paraneoplastic syndromes with unclear pathogenesis.

AIM

The aim of the present study was to find the frequency of autoimmune phenomena in solid tumors of various origin, location and status of the tumor.

PATIENTS AND METHODS

Between 2000 and 2014 we studied 1083 patients with solid tumors that were diagnosed and treated in St George University Hospital, Plovdiv.

RESULTS

We found higher incidence of these phenomena in prostate and ovarian carcinomas (9.01% and 5.6%, respectively) than in other solid tumors. Their distribution by type of autoimmune disease showed that vasculitis, polyneuritis and autoimmune hemolytic anemia have the highest frequency of all. Immune thrombocytopenia, seronegative arthritis, psoriasis, polymyositis are less commonly documented. The autoimmune paraneoplastic phenomena manifest themselves metachronously, less commonly synchronously, with the tumor. In most cases, their clinical manifestation is a progressive disease or metastatic malignant disorder which respond favourably to therapy.

CONCLUSION

Paraneoplastic autoimmune phenomena are found very commonly in prostate and ovarian carcinomas. They occur in the course of the evolvement of neoplasm and can regress with medicamentous or surgical treatment of the malignoma.

Interleukin-1β as emerging therapeutic target in hematological malignancies and potentially in their complications

Interleukin-1β (IL-1β) is a pleiotropic cytokine that exerts multiple roles in both physiological and pathological conditions. It is produced by different cell subsets, and drives a wide range of inflammatory responses in numerous target cells. Enhanced IL-1β signaling is a common event in patients of hematological malignancies. Recent body of evidence obtained in preclinical models shows the pathogenic role of these alterations, and the promising therapeutic value of IL-1 targeting. In this review, we further highlight a potential contribution of IL-1β linking to complications and autoimmune disease that should be investigated in future studies. Hence, drugs that target IL-1 may be helpful to improve outcome or reduce morbidity in patients. Some of them are FDA-approved, and used efficiently against autoimmune diseases, like IL-1 receptor antagonist. In the clinic, however, this agent seems to have limited properties. Current improved drugs will allow to determine the true potential of IL-1 and IL-1β targeting as therapy in hematological malignancies and their related complications.

Acute lymphocytic leukemia mimicking spondyloarthritis in an adolescent: A case report and review of the literature

The present study describes the case of an 18-year-old adolescent male exhibiting acute lymphocytic leukemia (ALL), complicated by the onset of the symptom of sacroiliitis mimicking spondyloarthritis. Atypical features including an enlarged spleen, poor effects of non-steroidal anti-inflammatory drug therapy, low levels of hemoglobin, a low platelet count, a low neutrophil count and increased levels of monocytes, indicated the possibility of hematological malignancy. Bone marrow examination confirmed the diagnosis of ALL. The patient received chemotherapy and the symptoms were dramatically relieved. To the best of our knowledge, the current study reports the second published case of a patient with ALL presenting with sacroiliitis. Sacroiliitis as an onset manifestation of ALL may result in misdiagnosis, therefore, a differential diagnosis is essential when atypical features are present.

Characteristics and prognosis of colorectal cancer associated with rheumatic disease

It is well known that host immunity plays an important role in the defense against colorectal cancer (CRC) progression. The effects of autoimmune diseases, such as rheumatic disease (RD) in which the immune system is deregulated, on this immunity have not been fully investigated. The medical records of 1299 consecutive patients diagnosed with primary colorectal cancer who underwent surgical resection were retrospectively reviewed. The clinicopathologic factors of 28 subjects with RD (RD group) were compared with those of 1271 patients without RD (non-RD group). Compared to the non-RD group, the RD group was typified by a predominance of females (P < 0.01), older age (P < 0.01), and a lower incidence of rectal cancer (P = 0.02). Although no difference was observed between the groups in terms of TNM classification, disease-free and overall survival were significantly poorer in the RD group in both univariate and multivariate analyses. Subjects who had RD for more than 10 years tended to have a higher frequency of lymph node metastasis (P = 0.06) and a significantly higher incidence of synchronous distant metastasis (P = 0.035) at the time of cancer diagnosis. RD was associated with a significantly poorer prognosis of colorectal cancer, suggesting that deregulation of the immune system by autoimmune diseases may adversely affect the host immune defense against colorectal cancer progression.

Polyangiitis with granulomatosis as a paraneoplastic syndrome of B-cell lymphoma of the lacrimal gland

Introduction. The clinical course of an autoimmune paraneoplastic syndrome parallels the natural history of the primary malignancy. In most cases, such paraneoplastic are syndromes hardly distinguishable from idiopathic autoimmune diseases. A case of polyangiitis with granulomatosis as a paraneoplastic syndrome in a patient with B-cell Lymphoma of the lacrimal gland has not yet been reported. Case Presentation. We present the case of a male patient with a B-cell Lymphoma of the lacrimal gland, who debuted with symptoms similar to rheumatoid arthritis and acute renal failure, secondary to polyangiitis with granulomatosis. The current pathophysiological hypotheses explaining the relationship between a lymphoproliferative disease and an autoimmune paraneoplastic disorder are discussed. Conclusion. Tumor-associated segmental necrotizing glomerulopathy is a very rare manifestation of glomerular diseases. Some atypical clinical features should increase the suspicion of an underlying tumor, in which case it is essential to treat the primary neoplasia, in order to control the autoimmune manifestations.

Paraneoplastic autoimmunity associated with testicular myeloid sarcoma and chronic myelomonocytic leukemia

Myeloid sarcomas are rare extramedullary solid tumors composed of immature myeloid cells. The clinical presentations of these malignant neoplasms are highly variable, ranging from asymptomatic to localized mass effect. Here, we report an unusual case of myeloid sarcoma of the testis found in association with chronic myelomonocytic leukemia where the presenting symptoms were autoimmune pericarditis and migratory arthralgias and myalgias that preceded testicular enlargement by nearly three months. Treatment with both radical orchiectomy and leukemia-directed chemotherapy led to immediate reductions in symptom severity, suggesting that these early symptoms were paraneoplastic in origin. Review of the literature identified the association between hematological malignancies, including chronic myelomonocytic leukemia, and paraneoplastic autoimmune phenomena with features similar to polymyalgia rheumatica and rheumatoid arthritis. Importantly, rheumatologic symptoms related to these disease entities may be easily dismissed as vague or unrelated complaints or treated as purely rheumatologic conditions, thus delaying the formal diagnoses. Clinicians must recognize the common association between possible paraneoplastic rheumatologic symptoms and hematologic malignancies such as chronic myelomonocytic leukemia.

Cutting edge issues in polymyositis

Skeletal muscle is the target tissue of immunoflogistic processes in patients affected with idiopathic inflammatory myopathies (IIM). IIM are classified into three major forms: polymyositis (PM), dermatomyositis (DM), and inclusion body myositis. Recent data suggest that, in the major subsets of myositis, antigens in muscles drive a B-cell antigen-specific immune response. Moreover, some non-immunological mechanisms have been advocated. In this regard, an increased expression of Jo-1 and Mi-2 in muscle biopsies from PM and DM patients compared to normal muscle has been demonstrated; these candidate autoantigens in myositis are expressed at high levels in regenerating muscle cells rather than in mature myotubes. Myositis autoantigen upregulation has also been observed in neoplastic tissues, thus representing a potential link between cancer and autoimmunity in myositis. Myositis-specific autoantibodies (MSA) are disease markers and target intracellular proteins involved in key processes such as translocation and nuclear transcription. Myositis target antigens encompass aminoacyl-tRNA synthetases, the Mi-2 helicase/histone deacetylase protein complex, the signal recognition particle ribonucleoprotein, together with novel target antigens including p155/140, CADM-140, and SAE. Despite their high specificity for autoimmune myositis, MSA target non-muscle restricted proteins ubiquitary to all cell types, making the specific muscle involvement difficult to explain. Non-immunological mechanisms also seem to contribute to the pathogenesis of IIM; activation of endoplasmic reticulum stress response due to muscle regeneration and inflammation but independent to MHC-1 up-regulation has been recently reported in patients with myositis.

A case of adult-onset Still's disease (AOSD)-like manifestations abruptly developing during confirmation of a diagnosis of metastatic papillary thyroid carcinoma

A 68-year-old Japanese man was admitted to our hospital suffering from abrupt onset of high fever accompanied by arthralgia, myalgia, sore throat, macular eruption, and liver dysfunction. Six months before the onset of these manifestations, (18)F-fluoro-deoxy-glucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) had detected, unexpectedly, three calcified thyroid lesions without (18)F-FDG uptake. Two months before the onset of the present manifestations, ultrasonography-guided fine-needle aspiration had led to a diagnosis of papillary thyroid carcinoma (PTC). Soon after the occurrence of the rheumatic manifestations, a subsequent (18)F-FDG PET/CT scan showed not only the three thyroid lesions, the same as those in the previous scan, but also (18)F-FDG uptake in the thyroid lesion. A diagnosis of adult-onset Still's disease (AOSD)-like manifestations associated with PTC was made, and treatment with 40 mg/day of prednisolone (PSL) resolved the symptoms promptly. PSL was gradually tapered, without recurrence of the (AOSD)-like manifestations. Five months after the initiation of treatment with PSL, total thyroidectomy, followed by (131)I thyroid ablation treatment, was performed while the patient was on a PSL dose of 18 mg/day. Seven months after the thyroidectomy, the dose of PSL was tapered to 2 mg/day, and neither the AOSD-like manifestations nor the PTC relapsed. On confirming a diagnosis of AOSD, it may be necessary to consider the presence of an associated malignancy, including solid tumors such as PTC.

[Gastrointestinal tumors. Clinical manifestations of paraneoplastic rheumatic symptoms]

Paraneoplastic syndromes, as syndromes associated with malignancy, can present unrelated to tumor invasion or metastases. They can occur with varying clinical appearance and are often indistinguishable from idiopathic rheumatic symptoms. Some musculoskeletal disorders are more associated with malignancies. The therapy of rheumatic syndromes can itself have an effect on the tumorigenic process. The clinical severity of paraneoplastic rheumatic symptoms can in many cases aid in the assessment of tumor activity and the response to therapy. While generally an extensive search for occult malignancies in every older rheumatoid patient in cases with no indications of malignancy is not advisable, knowledge of rheumatic symptoms associated with malignancies aids in the important early detection of tumors, while avoiding unnecessary examinations.

Carcinoma of gall bladder presenting as dermatomyositis

Cancer-related muscle diseases are usually paraneoplastic disorders. Dermatomyositis (DM) is a type of inflammatory myopathy that is strongly associated with a broad range of malignant disorders. The malignancy can occur before, concomitantly or after the onset of myositis. The malignancies most commonly associated with DM are carcinomas of ovary, lung, stomach, colorectal and pancreas, as well as non-Hodgkin’s lymphoma. An association of DM with carcinoma of the gall bladder (GB) is extremely rare with only two previously reported cases in the literature. We report a case of carcinoma of GB with DM as the paraneoplastic manifestation.

Prevalence of paraneoplastic rheumatic syndromes and their antibody profile among patients with solid tumours

The aims of this study were to assess the prevalence of paraneoplastic rheumatic syndromes in a cohort of patients with newly diagnosed solid tumours and to describe their autoimmune profile, comparing it to the controls. Screening questionnaires (3,770) were distributed, and during a three-step study, 94 patients were confirmed to have both paraneoplastic syndrome and oncology diagnoses. Three control groups-patients with undifferentiated arthritis, Raynaud's phenomenon for non-malignant causes and solid tumours only-were designed to compare with the paraneoplastic cases and their immunology profile. The prevalence of paraneoplastic rheumatic syndromes was 2.65% (95% CI 0.21-3.20). The group of patients with arthritis and the group of patients with Raynaud's syndrome were found to prevail among other clinical presentations of paraneoplastic rheumatic syndromes. Both paraneoplastic syndromes were linked to malignancies of the urogenital system. Antinuclear antibodies were found to be similarly frequent in the paraneoplastic arthritis, paraneoplastic Raynaud's phenomenon and the solid tumour groups. No differences were observed when comparing paraneoplastic arthritis and undifferentiated arthritis, except that the patients with paraneoplastic arthritis were older. Comparing paraneoplastic Raynaud's to Raynaud's phenomenon, male preponderance in the paraneoplastic Raynaud's phenomenon group was observed, and the patients were obviously older. Paraneoplastic rheumatic syndromes are rare and more often occur in older patients. Among them, paraneoplastic arthritis and Raynaud's syndrome were the most frequent. The immunology profile does not help in discriminating between arthritis and paraneoplastic arthritis patients and is of limited use in Raynaud's differential diagnosis.

A role for human endogenous retrovirus-K (HML-2) in rheumatoid arthritis: investigating mechanisms of pathogenesis

Human endogenous retroviruses (HERVs) are remnants of ancient retroviral infections within the human genome. These molecular fossils draw parallels with present-day exogenous retroviruses and have been linked previously with immunopathology within rheumatoid arthritis (RA). Mechanisms of pathogenesis for HERV-K in RA such as molecular mimicry were investigated. To clarify a role for HERVs in RA, potential autoantigens implicated in autoimmunity were scanned for sequence identity with retroviral epitopes. Short retroviral peptides modelling shared epitopes were synthesized, to survey anti-serum of RA patients and disease controls. A novel real-time polymerase chain reaction (PCR) assay was also developed to quantify accurately levels of HERV-K (HML-2) gag expression, relative to normalized housekeeping gene expression. Both serological and molecular assays showed significant increases in HERV-K (HML-2) gag activity in RA patients, compared to disease controls. The real-time PCR assay identified significant up-regulation in HERV-K mRNA levels in RA patients compared to inflammatory and healthy controls. Exogenous viral protein expression and proinflammatory cytokines were also shown to exert modulatory effects over HERV-K (HML-2) transcription. From our data, it can be concluded that RA patients exhibited significantly elevated levels of HERV-K (HML-2) gag activity compared to controls. Additional factors influencing HERV activity within the synovium were also identified. The significant variation in RA patients, both serologically and transcriptionally, may be an indication that RA is an umbrella term for a number of separate disease entities, of which particular HERV polymorphisms may play a role in development.

Polymyositis, dermatomyositis and malignancy: a further intriguing link

The association between malignancy and autoimmune myositis has been largely described and confirmed by numerous epidemiological studies. The temporal relationship between the two pathologic conditions can vary: malignancy may occur before, at the same time or following the diagnosis of myositis. Beside these observations, the molecular mechanisms underlying this association are still unknown, even though it has been demonstrated a possible antigenic similarity between regenerating myoblasts and some cancer cell populations. To better identify peculiar histopathologic features common to cancer and myositis, we screened muscle biopsies from patients affected with polymyositis, dermatomyositis, myositis in association to cancer, and from patients affected with newly diagnosed cancer, but without myositis. Similarly to the histopatologic features that were observed in the muscle from myositis patients, especially in those with cancer associated myositis, in patients affected with malignancy at the clinical onset of disease we observed early sign of myopathy, characterized by internally nucleated and regenerating myofibers, most of them expressing the neural cell adhesion molecule. The hypothesis that in a particular subset of individuals genetically predisposed to autoimmunity, an initial subclinical tumor-induced myopathy may result in an autoimmune myositis, represents a further intriguing link behind the association of these two conditions.

Subclinical myopathy in patients affected with newly diagnosed colorectal cancer at clinical onset of disease: evidence from skeletal muscle biopsies

OBJECTIVE

To evaluate skeletal muscle biopsy from asymptomatic patients affected with newly diagnosed colorectal cancer and to identify pathological features which may be indicative of tumor-associated muscle disorders, potentially leading to cachexia.

METHODS

Patients affected with newly diagnosed colorectal cancer at clinical onset of disease underwent biopsy of the rectus abdominis muscle during elective laparoscopic tumor resection, before chemotherapeutic treatment. Morphometric analyses, ATPase histochemistry and immunohistochemical studies using antibodies directed to N-CAM and to MHC-emb, two sound makers of muscle denervation and injury-induced muscle regeneration, were performed on intraoperative muscle biopsies from ten patients. Muscle biopsies from rectus abdominis of seven subjects affected with non-neoplastic condition, which underwent laparoscopic surgery, were used as controls.

RESULTS

In patients' biopsies, we observed a surprisingly high percentage of myofibers with internalized or central nuclei compared to controls (9.15 +/- 8.9 versus 0.6 +/- 0.9, p<0.0003). In addition, in the 30% of patients, small myofibers expressing the MHC-emb have been identified (0.4 +/- 0.5 positive fibers/mm(2)), while in 50% of patients, larger fibers positive for N-CAM have also been detected (0.7 +/- 1.1 positive fibers/mm(2)), suggesting that investigated muscle biopsies exhibit other evidence of muscle fiber injury/regeneration and/or denervation. Among the 10,000 analysed myofibers in control biopsies, no MHC-emb and N-CAM-positive muscle fibers have been detected. Thus, patients affected with newly diagnosed colorectal cancer at clinical onset of disease display early signs of a subclinical myopathy.

DISCUSSION

Factors and mechanisms of this cancer-associated myopathy are yet unknown. The facts that the great majority of the abnormally nucleated myofibers are of the fast type and that regenerating myofibers are present, suggest a myogenic response to the colorectal cancer and not to the laparoscopic modalities of the biopsy harvesting. Follow-up of the patients will elucidate the clinical relevance of our observation, and further studies investigating the molecular mechanism underlying this early cancer-associated myopathy will hopefully provide some pathogenetic clues leading to the identification of potential specific targets for therapeutic intervention to prevent tumor cachexia.

Musculoskeletal syndromes associated with malignancy (excluding hypertrophic osteoarthropathy)

PURPOSE OF REVIEW

To examine recent data about the association between rheumatic disorders and cancer. This article focuses on paraneoplastic rheumatic disorders, which usually precede by a short period of time the diagnosis of malignancy, and on malignant transformation, which occurs late in the course of rheumatic disorders. Evidence of causality between malignancies and rheumatic disorders was reviewed based on statistical indicators (standardized incidence ratios and odds ratios) and by applying Bradford Hill's criteria of causality.

RECENT FINDINGS

Firm epidemiological evidence was found attesting that dermatomyositis and polymyostis may present as paraneoplastic syndromes. Several other musculoskeletal disorders may be present akin to paraneoplastic syndrome, based on clinicians' impressions, but with scarce epidemiological evidence supporting a causal determinism. In contrast, robust evidence has accumulated on the role of longstanding rheumatoid arthritis, Sjögren's syndrome and systemic sclerosis as premalignant conditions. Evidence that systemic lupus erythematosus may evolve into lymphoma is equivocal.

SUMMARY

The link between malignancies and rheumatic disorders may impact on clinical practice. First, paraneoplastic rheumatic syndromes can provide the clinician with hints for earlier diagnosis of occult cancer. Second, the risk of malignant transformation during the course of rheumatic disorders may motivate the search for strategies aimed at prevention.

Rheumatic disorders as paraneoplastic syndromes

The long-established observation that some rheumatologic disorders (RDs) are associated with--or precede--the clinical manifestations of a variety of solid and hematological tumors represents an important clue for the early diagnosis and effective treatment of the cancers. Inflammatory myopathies, seronegative rheumatoid arthritis and some atypical vasculitides are the most frequently reported paraneoplastic RDs, although paraneoplastic scleroderma- and lupus-like syndromes, erythema nodosum, and Raynaud's syndrome have also been observed. Generally, the clinical course of a paraneoplastic RD parallels that of the cancer, and surgical removal of the tumor or its medical treatment usually results in a marked regression of the clinical manifestations of the RD. Most paraneoplastic RDs are difficultly distinguishable from idiopathic RDs. Even so, some atypical features of the clinical presentation raise the suspicion of an underlying tumor. This review summarizes current hypotheses for the pathogenesis that leads a tumor to present as an RD and discusses the clinical features that help distinguish paraneoplastic from idiopathic RDs.

Seronegative arthritis in patient with solitary bone plasmacytoma

We report a patient with localized focus of the bone destruction due to a rare disease, solitary bone plasmacytoma (SBP). The patient suffered from arthritis, mimicking seronegative rheumatoid arthritis. To our knowledge, it is the first description of coexistence of arthritis and SBP.