Primary lung cancer associated with polymyositis/dermatomyositis, with a review of the literature

Approach to Pulmonary Nodules in Connective Tissue Disease

The assessment of pulmonary nodules is a common and often challenging clinical scenario. This evaluation becomes even more complex in patients with connective tissue diseases (CTDs), as a range of disease-related factors must also be taken into account. These diseases are characterized by immune-mediated chronic inflammation, leading to tissue damage, collagen deposition, and subsequent organ dysfunction. A thorough examination of nodule features in these patients is required, incorporating anatomic and functional information, along with patient demographics, clinical factors, and disease-specific knowledge. This integrated approach is vital for effective risk stratification and precise diagnosis. This review article addresses specific CTD-related factors that should be taken into account when evaluating pulmonary nodules in this patient group.

Causality Assessment Between Idiopathic Inflammatory Myopathies and Lung Cancer: A Bidirectional 2-Sample Mendelian Randomization

BACKGROUND

Although observational studies have revealed associations between idiopathic inflammatory myopathies (IIMs) and lung cancer (LC), they have not established a causal relationship between these 2 conditions.

METHODS

We used a 2-sample Mendelian randomization approach to examine the bidirectional causal associations between IIMs and LC, using single-nucleotide polymorphisms selected from high-quality genome-wide association studies in the FinnGen database. Sensitivity analyses were conducted to assess potential heterogeneity and pleiotropy impacts on the Mendelian randomization results.

RESULTS

Our analysis demonstrated a positive causal effect of genetically increased IIM risk on LC (odds ratio, 1.114; 95% confidence interval, 1.057-1.173; p = 5.63 × 10 -5 ), particularly on the lung squamous cell carcinoma subtype (odds ratio, 1.168, 95% confidence interval, 1.049-1.300, p = 0.00451), but not on lung adenocarcinoma or small cell lung cancer. No causal effect of LC on IIMs was identified. Sensitivity analyses indicated that horizontal pleiotropy was unlikely to influence causality, and leave-one-out analysis confirmed that the observed associations were not driven by a single-nucleotide polymorphism.

CONCLUSION

Our findings offer compelling evidence of a positive causal relationship between IIMs and LC, particularly with regard to lung squamous cell carcinoma, in the European population. Conversely, there is no evidence of LC causing IIMs. We recommend that LC diagnosis consider the specific characteristics of IIMs.

Comparative analysis of immunotherapy responses in small cell lung cancer patients with dermatomyositis

Cancer-associated dermatomyositis (CAD), a paraneoplastic syndrome characterized by dermatomyositis (DM), frequently presents in association with small cell lung cancer (SCLC). Although the advent of immune checkpoint inhibitors (ICIs) has revolutionized cancer treatment, their efficacy and safety in patients with concurrent autoimmune diseases (AD) and malignancies remains uncertain. Several studies have suggested the safe administration of ICIs in patients with AD, indicating that successful cancer therapy can alleviate CAD symptoms. Conversely, other studies have raised concerns about the potential for ICIs to exacerbate AD flares or immune-related adverse events (irAEs). A comparative analysis of two cases from our institution emphasizes the variability in ICI responses among SCLC patients with CAD. One patient, previously reported as a case study, exhibited significant clinical improvement in DM symptoms after ICI administration, whereas the other developed severe exfoliative skin changes and experienced an unfavorable prognosis. This variability emphasizes the need for careful patient selection and close monitoring during ICI treatment. We hypothesized that overweight or obese individuals and those with severe initial skin lesions and elevated lactate dehydrogenase levels are more susceptible to developing irAEs following ICI therapy. Therefore, caution is advised when considering immunotherapy in these patients.

Small cell lung cancer with dermatomyositis: a case report

Dermatomyositis represents an autoimmune disorder characterized by notable skin and muscular manifestations. The annual incidence of dermatomyositis stands at approximately (5~10)/1 million individuals. Notably, patients with malignant tumors exhibit an elevated risk of developing dermatomyositis compared to the general population. However, in cases where dermatomyositis co-occurs with malignancy, the efficacy of hormone therapy alone tends to be suboptimal. Moreover, reports addressing the correlation between tumor treatment and the management of dermatomyositis are scarce. A 60-year-old male patient presented with dermatomyositis, initially manifesting through symptoms such as rash, muscle weakness, and dysphagia. Despite undergoing standard hormone therapy, there was no discernible improvement in the dermatomyositis symptoms. Considering the patient's concomitant troublesome cough, further investigations were conducted, including CT, PET-CT, and pathological biopsy. These assessments confirmed the diagnosis of limited-stage small cell lung cancer (T1cN3M0 IIIB). Notably, in this patient, dermatomyositis was suspected to be a paraneoplastic syndrome associated with small cell lung cancer. Standard chemotherapy and radiotherapy were employed to treat the small cell lung cancer, resulting in partial remission after two treatment cycles. As the malignancy regressed, a notable improvement in dermatomyositis symptoms was observed, subsequently leading to a gradual reduction in the prescribed hormone dosage. In conclusion, we present a comprehensive case study of dermatomyositis as a paraneoplastic syndrome throughout the treatment process. The response to tumor therapy coincided with the amelioration of dermatomyositis symptoms. Therefore, diligent malignancy screening is imperative for patients diagnosed with dermatomyositis.

Dermatomyositis Associated with Lung Cancer: A Brief Review of the Current Literature and Retrospective Single Institution Experience

Dermatomyositis is a rare inflammatory myopathy that is often related to lung cancer. In this retrospective observational study, we analyzed data from patients diagnosed with lung cancer at Soroka University Medical Center between January 2017 and July 2021. A total of 689 patients with lung cancer were included in this study, 97 of whom had small cell lung cancer and 592 had non-small cell lung cancer. We identified a single patient (60-year-old female) who presented with signs and symptoms of dermatomyositis, which was later confirmed to be associated with lung cancer as a paraneoplastic syndrome. Both our study and a recent review of the literature illustrate the temporal link between dermatomyositis and lung cancer, as well as reinforce the need for heightened cancer screenings in DM patients.

Immune checkpoint inhibitor therapy in a patient with small cell lung cancer and anti-transcriptional intermediary factor 1-γ antibody-positive dermatomyositis: A case report

Autoimmune diseases (ADs) are closely related to cancers; 30% of dermatomyositis (DM) cases are associated with malignancy. In lung cancer patients accompanied by DM, the most frequent cancer type is small cell lung cancer (SCLC). Anti‐transcriptional intermediary factor 1 γ (anti‐TIF1γ) antibody is a promising marker for the assessment of cancer risk in DM patients. The recent use of immune checkpoint inhibitors (ICIs) for extensive‐stage SCLC has improved patient outcomes. However, clinical trials of ICI excluded most patients with ADs because of the increased risk of toxicity. Nevertheless, recent evidences suggest that ICI may be appropriate for AD patients. A 76‐year‐old man diagnosed with extensive‐stage SCLC and anti–TIF1γ Ab‐positive DM developed limb weakness and typical skin manifestations of DM. Positron emission tomography‐computed tomography showed diffuse uptake in all muscles. The results of a nerve conduction study and electromyography were consistent with acute myopathy. Electron microscopy showed tubuloreticular inclusions in endothelial cells. He was treated with corticosteroids for DM and chemotherapy with atezolizumab for SCLC. Despite concerns regarding the use of ICI because of DM, atezolizumab was administered under close observation. After treatment, tumor size decreased and his symptoms improved significantly. We believe that the response of SCLC to chemotherapy including ICI, had a positive effect on the improvement of DM. Clinicians should consider ICIs for SCLC patients with DM and carefully monitor the patient's symptoms during treatment.

Polymyositis as a paraneoplastic syndrome of a patient with primary pulmonary lymphoepithelioma-like carcinoma: a case report and literature review

Background

Pulmonary lymphoepithelioma-like carcinoma (LELC) is a rare type of non-small cell lung cancer, which mostly occurred in non-smoking Asian populations. The prognosis of this tumor is better than other lung cancers. Polymyositis, a kind of idiopathic inflammatory myopathies, may negatively affect the prognosis of patients with lung cancer as a paraneoplastic syndrome (PNPS). LELC is seldomly accompanied by PNPS, thus the treatment strategy and prognosis should be discussed.

Case presentation

We report a 49-year-old female patient who was hospitalized for “symmetric limb weakness and pain for more than 2 months”. Glucocorticoid-based anti-inflammatory therapy had been performed for over 3 weeks before the patient was hospitalized, however, in vain. The result of serum autoimmune antibody showed Anti-nRNP/Sm ( +). The serum level of myoglobin, lactate dehydrogenase and creatine kinase elevated significantly. An electromyogram revealed peripheral nerves injury and myogenic damages. Imaging showed a mass in the posterior basal segment of the left lung. A percutaneous transthoracic needle biopsy was performed and the pathological result was LELC. The patient was diagnosed with pulmonary LELC accompanied by polymyositis. Positron emission tomography-computed tomography (PET-CT) showed only ipsilateral hilar and mediastinal lymph nodes metastasis. Video-assisted thoracoscopic left lower lobectomy and systematic mediastinal lymphadenectomy were performed. The postoperative pathological stage was T2N2M0, IIIA (UICC 8th), and the patient received adjuvant chemotherapy and subsequent radiotherapy. The patient was followed up for 5 months with no recurrence of tumor and the limb weakness and pain were relieved apparently after the successful comprehensive treatment of her primary tumor.

Conclusion

Pulmonary LELC is a rare subtype of non-small cell lung cancer seldomly accompanied by PNPS. Though polymyositis is associated with lung cancer, it is easy to ignore this relationship when a patient is diagnosed with LELC in the clinic. Surgery based comprehensive treatment of primary tumor can lead to a prospective prognosis in pulmonary LELC patients with PNPS. And successful treatment of pulmonary LELC can also improve symptoms of PNPS.

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.

Paraneoplastic myopathy in pancreatic cancer: a case report and literature review

Dermatomyositis (DM) and polymyositis (PM) are both immune-mediated inflammatory myopathies known to occur in paraneoplastic syndromes associated with a new diagnosis of malignancy, most commonly breast, ovarian, lung, pancreatic, stomach, colorectal, and Non-Hodgkin’s lymphoma¹ in DM and breast, lung, bladder cancer, and Non-Hodgkin’s lymphoma in PM. ^2,3,4 While inflammatory markers such as creatine kinase (CK) may be elevated with either DM or PM, marked elevation is rare. Herein, we report a case of newly diagnosed pancreatic cancer presenting with inflammatory myopathy and marked CK elevation. We review the frequency of PM as a paraneoplastic syndrome, the association with marked CK elevation, and the association with pancreatic cancer.

[Dermatomyositis with squamous cell carcinoma of the lungs secondary to nivolumab treatment: a case report]

A 74-year-old man was administered nivolumab to treat recurrent squamous cell carcinoma of the lungs. He developed fatigue, redness on the front of his neck, muscle weakness, and difficulty in swallowing after receiving the third course of nivolumab. Physical and neurological examinations showed proximal limb muscle weakness, periorbital erythema, and erythema of the front of his neck as well as fingers. Laboratory investigations revealed elevated serum CK and aldolase levels, and he was diagnosed with dermatomyositis. We initiated steroid pulse therapy and intravenous immunoglobulin therapy; however, he died of advanced lung cancer. Immune checkpoint inhibitor-induced neuromuscular disease is increasingly being observed in clinical practice. We report a rare case of dermatomyositis with squamous cell carcinoma of the lungs secondary to nivolumab treatment.

Dermatomyositis Anteceding Lung Adenocarcinoma

Dermatomyositis is often presented as paraneoplastic syndrome. The diagnosis of dermatomyositis can prompt clinicians to further investigate the underlying cause, in particular malignancy. This case report illustrates the association of lung adenocarcinoma and dermatomyositis with antecedent presentation of cutaneous and musculoskeletal manifestations, one year prior to the diagnosis of carcinoma.

Paraneoplastic syndromes in lung cancer and their management

Paraneoplastic syndromes are most frequently associated with lung cancer. This review considers a variety of paraneoplastic syndromes associated with lung cancer and discusses their pathophysiology, clinical features and management options.

Dermatomyositis associated with adenocarcinoma of the lung: A case report

The association of dermatomyositis and underlying malignancies, especially small cell and squamous cell carcinoma of the lung, has been recognized a long time ago. We report the case of a 63-year-old male chronic smoker with adenocarcinoma lung associated with dermatomyositis. The occurrence of dermatomyositis should be considered as a potential presentation of paraneoplastic syndromes and physicians encountering similar clinical situations should perform extensive diagnostic work-up to exclude underlying neoplastic lesions.

Ground-glass opacity heralding invasive lung adenocarcinoma with prodromal dermatomyositis: a case report

Background

Dermatomyositis, an inflammatory myopathy with cutaneous involvement, is associated with malignancy and often manifests paraneoplastically. While co-occurrence with small cell carcinoma is well attested, primary lung adenocarcinoma, which may present as focal ground-glass opacification on computed tomography of the thorax, is less frequently coincident.

Case presentation

We report the case of a 72-year-old female patient with dermatomyositis — treated with a combination of prednisone, methotrexate, and intravenous immunoglobulin — and an indolent, subsolid, non-hypermetabolic pulmonary lesion, which was determined to be invasive primary lung adenocarcinoma. Supporting a paraneoplastic basis, immunosuppressive therapy was discontinued following tumor excision without relapse of signs or symptoms of dermatomyositis.

Conclusions

While dermatomyositis prodromal to lung adenocarcinoma is not without precedent, association with an indolent, subsolid lesion has, to the best of our knowledge, not been reported. The case described herein illustrates the importance of maintaining a high index of suspicion for malignancy in the setting of dermatomyositis.

A case report of dermatomyositis associated with small cell lung cancer

Dermatomyositis associated with lung cancer is uncommon. Dermatomyositis associated with small cell lung cancer is very rare and carries a poor prognosis. We present a case of a patient with dermatomyositis associated with small cell carcinoma of the lung and review the literature.

Autoimmune paraneoplastic syndromes associated to lung cancer: A systematic review of the literature Part 4: Neurological paraneoplastic syndromes, involving the peripheral nervous system and the neuromuscular junction and muscles

The development of new immune treatment in oncology and particularly for lung cancer may induce new complications, particularly activation or reactivation of auto-immune diseases. In this context, a systematic review on the auto-immune paraneoplastic syndromes that can complicate lung cancer appears useful. This article is the fourth of a series of five and deals mainly with neurological paraneoplastic syndromes involving the peripheral nervous system and the neuromuscular junction and muscles.

Dermatomyositis as a symptom of primary lung cancer: A case report and review of the literature

Dermatomyositis (DM) is a rare autoimmune disease associated with manifestations of proximal muscle weakness and typical cutaneous skin rash. Patients with DM have a higher incidence rate of cancer, compared with the general population, since DM usually presents as a paraneoplastic syndrome. The present study reports a case of a 69-year-old male patient presenting with typical cutaneous rash and aggravating proximal muscle weakness for 3 months. When first admitted to the Department of Dermatology of Shandong Provincial Hospital Affiliated to Shandong University (Jinan, China), the patient was diagnosed with DM. Subsequently, chest computed tomography scan revealed a neoplasm located in the right upper lobe. Video-assisted thoracoscopic surgery right upper lobectomy and lymph node dissection were then performed. The patient experienced a fast recovery from the surgery. The removal of the neoplasm clearly improved the symptoms of DM. Considering that DM is usually associated with the existence of a tumor, cases of DM require a thorough diagnostic investigation in order to exclude an underlying malignancy.

A mild form of dermatomyositis as a prodromal sign of lung adenocarcinoma: a case report

Background

Dermatomyositis is an idiopathic connective tissue disease characterized by specific cutaneous findings and inflammatory lesions in the muscle biopsy. An association between dermatomyositis and malignancy, including breast, ovarian, lung and colon cancer was recognized many years ago, with an incidence of malignancy in approximately 20 % of cases. Dermatomyositis is hypothesized to be an autoimmune reaction against factors or hormones secreted by the tumor; however, the exact autoimmune mechanism of the disease pathogenesis remains unknown.

Case presentation

Here we report a case of a woman with dermatomyositis who was diagnosed with lung adenocarcinoma in the setting of weight loss, progressive fatigue and muscle weakness. A 43-year-old Caucasian woman was referred to our hospital by her physician for suspected contact dermatitis since she described mild itching sensations in her arms and legs as her major symptom. A physical examination revealed erythematous papular lesions over her metacarpophalangeal and proximal interphalangeal joints together with a periungual involvement with redness, hyperkeratosis and capillary telangiectasia along the distal nailfolds on her hands. She was unaware of these features and they did not seem to bother her. A thorough examination of her medical history, however, revealed more symptoms. Pain and weakness in the muscles of her proximal extremities and neck flexor muscles led to difficulty in raising her arms and climbing stairs. At the same time she experienced swallowing difficulties and reported an uncharacteristic weight loss of 10 kg in the last 3 months. The results of laboratory tests showed increased values of serum creatine kinase and myoglobin. An electromyogram, a skin biopsy and a muscle biopsy confirmed the diagnosis of dermatomyositis. A computed tomography of her thorax showed a nodular mass in the upper lobe of her right lung. A histological examination of the lung biopsy showed an adenocarcinoma of moderate differentiation. She was diagnosed with paraneoplastic dermatomyositis as the first sign of a lung adenocarcinoma.

Conclusions

Our case report highlights the importance of a thorough search for underlying malignancy in patients with dermatomyositis even if dermatomyositis has a mild appearance or a discrete skin manifestation.

Squamous Cell Lung Cancer Associated With Systemic Sclerosis

We here describe a 50-year-old woman diagnosed with squamous cell lung cancer (SqLC) with underlying interstitial lung disease (ILD) 14 years after a diagnosis of systemic sclerosis (SSc). We reviewed the literature and collected 21 well-documented cases with SqLC associated with SSc including the present case. Several characteristics of SqLC associated with SSc have been found. First, the average age at diagnosis of SqLC is 57 years, which is much younger than that reported for patients without SSc. Second, SqLC could occur even in never or light smokers, although SqLC usually has a strong association with smoking history. Third, two-thirds of the available cases have ILD. In addition, SqLC developed in the area of ILD in most cases with ILD. Fourth, SqLC generally occurs after a long period from the diagnosis of SSc; the average of this interval reaches 12 years. It would be helpful to know these features so that physicians follow up and treat SSc patients adequately.

A 62-year-old man with skin rash and an abnormal chest radiograph

A 62-year-old man developed a scalp rash 2 months ago, followed by bilateral eyelid swelling. The nonpruritic rash then spread to involve most of his skin. He also had fatigue, muscle weakness, mild muscle soreness with activity, and dysphagia for solid foods for the last 3 weeks. He had no other symptoms. He had a 50 pack-year history of smoking and drank two to three shots of alcohol daily.

Relapse of Dermatomyositis after 10 Years in Remission Following Curative Surgical Treatment of Lung Cancer

A 55-year-old woman with dermatomyositis and small cell lung cancer was successfully treated with surgery followed by combination chemotherapy in 1987. She had been in remission without further immunosuppressive therapy for 10 years. However, myositis with cutaneous manifestations specific for dermatomyositis relapsed when the patient was 69 years old. Intensive examinations revealed no neoplasm, and she responded to a moderate dose of systemic corticosteroids. This case suggests a long-lasting autoimmune abnormality in dermatomyositis and that a neoplasm is an important factor in eliciting an occult dermatomyositis.

Respiratory failure in a patient with dermatomyositis

Since its original description in 1956 the association between interstitial lung disease and polymyositis (PM) and dermatomyositis (DM) has become well established. Interstitial lung disease (ILD) can be a significant complication in rheumatic diseases (RDs). Although most patients with RD do not develop clinically evident ILD, these systemic autoimmune disorders are estimated to be responsible for approximately 25% of all ILD deaths and 2% of deaths due to all respiratory causes. Radiologic abnormalities in DM are characterized by a high incidence of airspace consolidation. Non-Specific Interstitial Pneumonia (NSIP) is the most common form of lung disease, with a frequency in biopsies 4-fold greater than that of Usual Interstitial Pneumonia (UIP) in PM and a slightly smaller predominance in DM.

We report a case of a female patient, 57 years old, no former smoker, whose clinical history was onset in November 2008 with asthenia with muscle and osteoarticular pain especially located in the upper limbs and then also expanded to the lower limbs. The EMG was compatible with dermatomyositis in the acute phase. The patient received therapy with steroids and tacrolimus, also making several rounds of treatment with immunoglobulin. Given the recurrence of myositis in association with signs of poorly controlled interstitial lung disease, immunosuppressive therapy with Rituximab was administered. The Computed Tomography (CT) scans showed "bronchiectasis and traction bronchiolectasis, hypodense areas consistent with the phenomena of air trapping. The pattern of interstitial lung disease with fibrotic evolution seems consistent with NSIP.

The arterial blood gas analysis showed a pattern of hypoxic-hypercapnic respiratory failure (pH: 7,34, PaO₂: 67 mmHg; PaCO₂: 55 mmHg).

As a result of an episode of marked desaturation unresponsive to supplemental oxygen at high flows we proceeded to noninvasive mechanical ventilation with Helmet for 24 hours/24. This ventilatory support was maintained for a week, with resolution of the respiratory failure.

In this brief case report we want to highlight various pulmonary complications as a result of dermatomyositis. The progression of respiratory complications may also lead to a situation of respiratory failure, as in our patient, and require a noninvasive ventilatory treatment.

18F-FDG PET detection of unknown primary malignancy in dermatomyositis

Dermatomyositis is an inflammatory myopathy that has an association with malignancy in adults. We present a patient who initially presented with adenopathy and progressive muscular weakness and was diagnosed with dermatomyositis and lung carcinoma on further investigation. Whole-body PET/CT scan revealed diffuse proximal muscle hypermetabolism representing the inflammatory nature of dermatomyositis, and an intensely FDG-avid primary right lower lung small cell lung carcinoma and metastatic thoracic lymphadenopathy. PET/CT imaging may offer an "all-in-one" procedure as an alternative to other diagnostic procedures, reducing the number of unnecessary investigations in patients presenting with paraneoplastic syndromes searching for underlying malignancy.

Pleuropulmonary pathology in patients with rheumatic disease

Thoracic manifestations of rheumatic disease (RD) are increasingly recognized as a significant cause of morbidity and mortality worldwide. Rheumatologic underpinnings have been identified in a significant proportion of patients with interstitial lung disease. The 5 RDs most frequently associated with pleuropulmonary disease are (1) rheumatoid arthritis, (2) systemic lupus erythematosus, (3) progressive systemic sclerosis, (4) polymyositis/dermatomyositis, and (5) Sjögren syndrome. The onset of thoracic involvement in these diseases is variable. In some patients, it precedes the systemic disease or is its only manifestation. Moreover, there is a wide spectrum of clinical presentation ranging from subclinical abnormalities to acute respiratory failure. Histopathologically, the hallmark features of thoracic involvement by RD are inflammatory, targeting one or more lung compartments. The reactions range from acute to chronic, with remodeling by fibrosis being a common result. Although the inflammatory findings are often nonspecific, certain reactions or anatomic distributions may favor one RD over another, and occasionally, a distinctive histopathology may be present (eg, rheumatoid nodules). Three diagnostic dilemmas are encountered in patients with RD who develop diffuse lung disease: 1) opportunistic infection in the immunocompromised host, 2) drug toxicity related to the medications used to treat the systemic disease, and 3) manifestations of the patient's known systemic disease in lung and pleura. To confidently address the latter, the 5 major RDs are presented here, with their most common pleuropulmonary pathologic manifestations, accompanied by brief clinical and radiologic correlations.

Lung cancer and interstitial lung diseases: a systematic review

Interstitial lung diseases (ILDs) represent a heterogeneous group of more than two hundred diseases of either known or unknown etiology with different pathogenesis and prognosis. Lung cancer, which is the major cause of cancer death in the developed countries, is mainly attributed to cigarette smoking and exposure to inhaled carcinogens. Different studies suggest a link between ILDs and lung cancer, through different pathogenetic mechanisms, such as inflammation, coagulation, dysregulated apoptosis, focal hypoxia, activation, and accumulation of myofibroblasts as well as extracellular matrix accumulation. This paper reviews current evidence on the association between lung cancer and interstitial lung diseases such as idiopathic pulmonary fibrosis, sarcoidosis, systemic sclerosis, dermatomyositis/polymyositis, rheumatoid arthritis, systemic lupus erythematosus, and pneumoconiosis.

Malignancy in myositis

Dermatomyositis is associated with an underlying malignancy in about 24% of cases. This association is also true for polymyositis but is less prominent. The malignancy is usually an adenocarcinoma of the ovary, lung, or gastrointestinal tract in Western countries and nasopharyngeal carcinoma in Southeast Asia, Southern China, and Northern Africa. Factors predictive of malignancy in myositis patients include more severe skin and muscle disease and the absence of overlap connective tissue disease features, such as interstitial lung disease. Anti-p155/140 antibodies have a strong predictive value for malignancy in adult patients. Patients with dermatomyositis or polymyositis require an evaluation for occult malignancy at the time of diagnosis and, in some cases, in the event of a subsequent recurrence. This paraneoplastic phenomenon may stem from an immune reaction to antigens expressed in both cancer cells and regenerating fibers in affected muscle.

Paraneoplastic muscle disease

In paraneoplastic muscle disease, the malignancy may remotely affect neuromuscular transmission or incite muscle inflammation or necrosis. In several of these diseases, an autoimmune basis for the muscle disease has been established and has become a defining feature. These paraneoplastic muscle diseases may be the first manifestation of a malignancy, and their diagnosis thus demands a vigilant search for an underlying tumor. This article is focused on inflammatory and necrotizing myopathies and disorders of neuromuscular transmission that may arise in the setting of malignancy and are considered paraneoplastic phenomena.

Lung adenocarcinoma, dermatomyositis, and Lambert-Eaton myasthenic syndrome: a rare combination

The incidence of lung neoplasms is increasing in Brazil and in the world, probably as a result of the increase in smoking. Due to the greater number of cases, atypical presentations appear. We report the case of a 66-year-old hypertensive male smoker who presented progressive proximal muscular weakness and, in two months, evolved to dysphagia, dysphonia, and V-shaped skin lesions on the chest. A chest X-ray showed a spiculated pulmonary nodule in the right upper lobe. The biochemical analysis revealed elevated creatine kinase levels. After complementary tests and biopsies, the patient underwent right upper lobectomy. Histopathology showed a moderately differentiated adenocarcinoma. The overall analysis of the case and a review of the literature allow us to suggest that the clinical profile of the patient was a result of an overlap of two paraneoplastic syndromes (dermatomyositis and Lambert-Eaton myasthenic syndrome) secondary to lung adenocarcinoma.

Case report: dramatic recovery of lung adenocarcinoma-associated dermatomyositis with targeted lung cancer therapy alone

This case report details the sudden onset of severe dermatomyositis (DM) symptoms followed by rapid progression of adenocarcinoma of the lung and an obvious diminution of the primary tumor with the administration of lung cancer targeted drug therapy alone, followed by nearly complete disappearance of the DM symptoms, with no conspicuous improvement in the DM symptoms when using corticosteroids.

Cancer-associated myositis: clinical features and prognostic signs

Idiopathic inflammatory myositis is characterized by progressive weakness of the proximal muscles. There is a higher risk of malignancy than in the normal population. The aim of this study was to evaluate the frequency of malignancy among 251 myositis patients. We also compared clinical and immunological characteristics of cancer-associated myositis with primary myositis. There were no malignancies among polymyositis, overlap, or juvenile myositis patients. Twenty-two of ninety dermatomyositis patients also had a malignant disease. Patients with cancer-associated dermatomyositis were significantly older than primary myositis patients and had more severe cutaneous and muscle symptoms. Dysphagia and diaphragmatic involvement were more frequent among cancer-associated patients, while extramuscular features were less frequent. After successful treatment of the malignancy, we were able to manage myositis symptoms. One-year survival rate was significantly better in primary dermatomyositis patients. The subset of cancer-associated myositis differs from primary myositis in many aspects of its clinical and immunological features. Prognosis and life expectancy in cancer-associated myositis patients is determined by the underlying malignant disease. Therefore, age- and sex-specific examinations for detection of an underlying malignancy are important in the management of patients with dermatomyositis.

Paraneoplastic Polymyositis Associated With Squamous Cell Carcinoma of the Lung

An association between polymyositis and lung cancer has been debated. Published data usually lack either lung cancer histologic differentiation or biopsy-based delineation between polymyositis and dermatomyositis. We reported a case of a 56-year-old man with squamous cell carcinoma of the lung confined to a single hilar lymph node presenting with biopsy-proven polymyositis of 3 months in duration. Polymyositis should be considered as a potential presentation of paraneoplastic syndrome, especially in patients who are at risk for lung cancer.

Paraneoplastic rheumatic syndromes

Paraneoplastic symptoms caused by a malignancy but not directly related to tumour invasion are the result of a wide variety of tumour-derived biologic mediators, such as hormones, peptides, antibodies, cytotoxic lymphocytes, autocrine and paracrine mediators. Recognition of paraneoplastic syndromes is important, as it may lead to an early diagnosis of cancer. On the other hand, the clinical severity of the symptoms can be used as a guide to the extent of response to underlying tumour therapy. The quality of life of the patient is affected, therefore the palliative treatment of paraneoplasia is very important.

High-Grade Neuroendocrine Carcinoma of the Lung Presenting an Unusual Spread Mimicking Pleural Mesothelioma Associated with Dermatomyositis

Neuroendocrine tumors of the lung comprise a heterogeneous group of tumors that represents a spectrum of disease from typical carcinoid tumors to the high-grade neuroendocrine carcinomas (large-cell neuroendocrine carcinomas and small-cell carcinomas). The high-grade neuroendocrine carcinomas are characterized by early metastasis and poor prognosis. The peripheral location and especially the massive pleural spread are rare for a high-grade neuroendocrine carcinoma. We report a case in which a high-grade neuroendocrine carcinoma, associated with dermatomyositis, presented an unusual pattern of progression, mimicking malignant pleural mesothelioma on diagnostic imaging.

Malignancy in patients with inflammatory myopathy

The most recent evidence from population-based cohort studies confirms the association between malignancy and dermatomyositis and polymyositis. These studies show an even stronger association between polymyositis and malignancy than previous studies, suggesting less misclassification. This is particularly true of one study that used pathologic criteria to distinguish between myositis subtypes. Recent data also confirm that the association for dermatomyositis and polymyositis is not purely caused by diagnostic suspicion or surveillance bias. More data are still required to determine individual cancer risks, although it appears that ovarian and lung cancer are associated with dermatomyositis while lung cancer and non-Hodgkin's lymphoma are associated with polymyositis. An association between malignant disease and inclusion body myositis has also been verified for the first time. Of interest, too, is the increasing number of reports documenting cases in which the clinical course of the myositis mirrors that of the cancer, supporting the notion that in some instances, myositis is a paraneoplastic disorder.