2016 Volume 56 Issue 3 Pages 189-193
Background. Thymic carcinoma is a cause of a cancer-associated dermatomyositis. Case. A 73-year-old female was referred to our hospital with sudden-onset dermatitis and was diagnosed with dermatomyositis. Since steroid therapy was accompanied by the waxing and waning of the patient's skin symptoms, cancer-associated dermatomyositis was suspected. Chest computed tomography revealed a lobular anterior mediastinal tumor of 42 mm in diameter with mediastinal and supraclavicular lymphadenopathy. Thymectomy with resection of the invaded pericardium and left brachiocephalic vein and lymphadenectomy were performed via median sternotomy. A pathological examination revealed a poorly differentiated squamous cell carcinoma of the thymus with metastatic lymph nodes (pT1aN2M0, stage IVb). Although the clinical symptoms of dermatomyositis were ameliorated soon after resection, the patient's skin rashes worsened after the recurrence of thymic carcinoma. Conclusion. The abrupt development of symptoms and the remission of skin symptoms in response to the therapeutic process were helpful as evidence of thymic cancer-associated dermatomyositis.
