The subject was a 46-year-old woman who visited our hospital complaining mainly of polyarthralgia and was diagnosed as having dermatomyositis. High-resolution computed tomography of the lungs revealed evidence of interstitial lung disease with coexistence of multiple nodular and cystic opacities. Because none of these patterns are characteristic of dermatomyositis-associated pulmonary involvement, a surgical lung biopsy was performed. Based on the histopathological findings, the subject was diagnosed as having coexisting dermatomyositis-associated interstitial pneumonia, lung lymphangioleiomyomatosis, and intrapulmonary lymph node. Since there is no report yet of cases with coexistent dermatomyositis associated with interstitial pneumonia and lung lymphangioleiomyomatosis, the coexistence was considered an event of chance. Dermatomyositis was believed to be the cause of intrapulmonary lymph node. It is thought that surgical lung biopsy should be considered in all patients with collagen vascular diseases who have a CT shadow that cannot be explained by the pulmonary collagenosis.