Successful management of interstitial lung disease in dermatomyositis complicated by malignancy: a case-based review.

Dermatomyositis (DM) is associated with interstitial lung disease (ILD) and malignancy. However, the coexistence of ILD and malignancy (DM–ILD–malignancy) is rare, and limited information exists regarding its management. Herein, we report the case of a 70-year-old man who developed DM with rapidly progressive ILD and advanced gastric cancer and provide a literature review of managing DM–ILD–malignancy. The patient presented with typical DM skin rashes and shortness of breath, which worsened within 1 month, without muscular symptoms. Additionally, the patient tested negative for myositis-specific autoantibodies (MSAs). Computed tomography revealed ILD and advanced gastric cancer, which was confirmed on endoscopic examination to be a poorly differentiated adenocarcinoma. Although the patient's ILD progressed rapidly, surgical treatment of the cancer was prioritized. Prednisolone (PSL) 0.5 mg/kg was initiated 3 days before surgery and increased to 1 mg/kg at 7 days postoperative. Remarkable improvement in the skin rash and ILD was observed, and the PSL dose was tapered without immunosuppressants. A literature review revealed that anti-melanoma differentiation-associated gene 5 and anti-aminoacyl transfer RNA synthetase antibodies are the predominant MSAs in DM–ILD–malignancy, and the optimal treatment should be determined based on several factors, including ILD patterns, and malignancy type and stage. In particular, lung cancer may be a risk factor for the acute exacerbation of ILD, and preceding immunosuppression would be useful. Furthermore, prioritizing surgery for gastric cancer is effective because of its paraneoplastic nature. [ABSTRACT FROM AUTHOR]