Pericardial artery lymphoma in a patient with dermatomyositis: A case report

A woman in her 60s presented with erythema on both elbows, dyspnea on exertion, discomfort, and swelling of the left upper extremity, followed by swelling and myalgia of the right upper and lower extremities. She was diagnosed with anti-transcriptional intermediary factor 1-γ antibody-positive dermatomyositis with interstitial pneumonia. The initial screening tests for malignant diseases including contrast-enhanced computed tomography, upper and lower endoscopy, and gynecological examination did not reveal any obvious abnormalities. The patient experienced two recurrent episodes of muscle weakness and dysphagia during treatment with intravenous glucocorticoids and cyclophosphamide. Five months after diagnosis, a bone marrow biopsy and positron emission tomography-computed tomography scan revealed a coronary malignant lymphoma with suspected systemic metastasis. Although chemotherapy was initiated, the patient ultimately succumbed to alveolar haemorrhage. Coronary lymphoma is very rare and there has been no report of cases associated with myositis. Positron emission tomography-computed tomography may be useful for searching malignancy in anti-transcriptional intermediary factor 1-γ antibody-positive dermatomyositis cases of recurrent relapse.