[A case of dermatomyositis with significantly high level of KL-6 associated with ovarian cancer].

The patient was a 58 year-old woman. Starting about seven months before the initial examination, the patient began to experience a general malaise, coupled with reddish purple scaling eruption on the MP joints, knuckles, elbows, and knees, and dark purplish erythema on both upper eyelids. About two months before the initial examination, the patient visited a local medical doctor because she began to experience arthralgia and muscular weakness. Based on the condition of her weakening proximal muscles and increased levels of myogenic enzymes, the patient was diagnosed as having Dermatomyositis. Oral administration of PSL (25 mg a day) was initiated, and the patient was referred to our department to undergo thorough examination. Although deterioration in muscular strength and elevation of myogenic enzyme levels were mild during the initial examination, the level of KL-6 was significantly elevated to 2600 U/ml. Numerous blood gas analyses and chest CT did not reveal any exacerbation of interstitial pneumonia. Various tests were performed to determine whether or not there was any malignancy, and although a small amount of ascites fluid was detected, diagnostic imaging revealed no clear abnormalities. Since cytological diagnosis of the ascites fluid was class V, an exploratory laparotomy was performed, and ovarian cancer complicated by peritoneal metastasis was discovered. As a result, the patient was diagnosed as having dermatomyositis accompanied by ovarian cancer. The level of KL-6 in the ascites fluid was significantly high at 10,900 U/ml, and immunohistological staining using anti-KL-6 antibodies confirmed the presence of KL-6 in the ovarian tumor, thus suggesting that KL-6 was produced by the ovarian cancer.