SESSION TITLE: Miscellaneous Global Case Reports
SESSION TYPE: Global Case Report
PRESENTED ON: Tuesday, October 29, 2013 at 01:30 PM - 02:30 PM
INTRODUCTION: Polymyositis (PM) and Dermatomyositis (DM) are well known to be associated with an increased risk for various cancers; among them all the histologic subtypes of lung cancer. Anti-synthetase syndrome (ASS) is encountered in about 25% of PM-DM subjects. ASS constitutes of specific anti-myositis antibodies and any of myositis, interstitial lung disease (ILD), raynaud phenomenon, fever, arthritis and mechanic`s hands. Few data exist regarding the association between ASS and lung cancer.
CASE PRESENTATION: Our patient was a 63 year old male, current smoker (75pack/years). He was diagnosed with COPD 2 years ago and arterial hypertension. He was admitted to our department complaining of fatigue, proximal muscle weakness and shortness of breath at mild exercise for the previous 2 months. Physical examination revealed scattered rales in both lungs, a hyperkeratotic rash in the lateral and palmar surface of both his hands, and a buttocks` rash. Chest radiography showed hyperinflation and a thickenning of the right paratracheal lining. Blood tests revealed an ESR 40mm/h and a Creatin Phosphokinase (CPK) levels of 2,470 U/L. Tumor markers were negative. A diagnosis of DM was suspected. Muscle biopsy and electromyogram confirmed a diagnosis of DM. Further, immunological testing revealed ANA titers of 1:320 and positive anti-Jo1 autoantibodies. Combined with the myositis and the hands` rash compatible with "mechanic`s hands", ASS was conclusively diagnosed. A Computed Tomography (CT) scan of the chest performed afterwards showed enlarged upper right paratracheal and subcarinal lymph nodes, a right lower lobe 1.5 cm nodule and sites of pleural thickening in the right hemithorax. Positron Emission Tomography (PET) scan was done to better evaluate the above findings. PET scan detected suggestive of malignancy uptake in the mediastinal lymph nodes and in the pleural lesions. A diagnostic bronchoscopy was then carried out. Transbronchial Needle Aspiration (TBNA) using a 21-gauge needle obtained cytology material from station 7 nodes which was diagnostic for Non Small Cell Lung Cancer (NSCLC), specifically adenocarcinoma (Stage IV: TxN2M1a). Consequently, a concurrent diagnosis of Dermatomyositis, especially ASS, and lung adenocarcinoma was made. The patient was then started on first line chemotherapy.
DISCUSSION: Dermatomyositis has been shown to carry an increased standardized incidence ratio for concomitant malignancy, raging from 2.4 to 6.2 in various studies (1). This risk is higher for DM compared to other inflammatory myopathies, thus identifying DM as a "paraneoplastic" disorder. However, it is not clear which are the risk factors predisposing a subject with DM to develop a malignancy. ASS comprises of a DM subgroup with positive Myositis specific autoantibodies (MSA`s) (Jo-1, Mi-2, PL-7, 155/140). A high incidence of ILD (80%) is encountered in ASS, but yet ILD is not uniformly met. It has been postulated that DM patients with ASS and MSA are associated with a significantly lower risk of malignancy than DM patients without ASS, suggesting for ASS a rather "protective" role (2). In a recent study, Jo-1 antibodies were present in 4.8% of concomitant DM and cancer patients, but in 15.9% of DM patients without malignancy (3). Overall, although ASS appears less commonly associated with cancer than non-ASS DM, cases of such an association exist in the current literature.
CONCLUSIONS: Currently, it is unknown which DM patients are more prone to malignancy and therefore should undergo more intense investigation to that direction. ASS is associated with ILD and, possibly, with a lower probability of concurrent cancer. However, our case report clearly shows that ASS without ILD may be associated with lung adenocarcinoma and that prompt evaluation is warranted.
Reference #1: 1. Buchbinder R, Forbes A, Hall S, et al. Incidence of malignant disease in biopsy-proven inflammatory myopathy. A population-based cohort study. Ann Intern Med. 2001 Jun 19;134(12):1087-95.
Reference #2: 2. Chinoy H, Fertig N, Oddis CV, et al. The diagnostic utility of myositis autoantibody testing for predicting the risk of cancer-associated myositis. Ann Rheum Dis 2007; 66(10):1345-9.
Reference #3: 3. Azuma K, Yamada H, Ohkubo M, et al. Incidence and predictive factors for malignancies in 136 Japanese patients with dermatomyositis, polymyositis and clinically amyopathic dermatomyositis. Mod Rheumatol 2011; 21(2):178-83.
DISCLOSURE: The following authors have nothing to disclose: Ilias Papanikolaou, Konstantinos Pagratis, Andreas Afthinos, Dionysios Zalachoris, Eleftherios Markatis, Ioanna Laina, Dimitrios Karantanis, Maria Gonidi
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