title: [A benign clear cell tumor of the lung that grew gradually over five years].
abstract: A 38-year-old man was found to have an abnormal shadow in his chest X-ray film during a general medical examination. A nodule with a homogeneous density and a clear margin was seen in the upper lobe of the right lung. Since this shadow gradually enlarged during a five-year follow-up period, he was admitted to our hospital. Chest contrast and dynamic CT scans and aortography showed characteristics of a benign tumor with somewhat rich vascularity. The doubling time of this tumor was about 430 days. Transbronchial brushing for cytologic study and a transbronchial biopsy showed no malignancy. However, the tumor was surgically resected because of its gradual growth over the five years. The resected tumor was histologically diagnosed as a benign clear cell tumor of the lung. This disease was first described by Leibow and Castleman in 1963, as a benign pulmonary tumor similar to metastatic renal cell carcinoma. This disease is extremely rare and only 61 cases have been reported: twenty cases, including the present case, in Japan and 41 in other countries.
authors.affiliation: First Department of Medicine, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Mishina
authors.forename: I
authors.initials: I
authors.lastname: Suzuki
authors.forename: M
authors.initials: M
authors.lastname: Fujino
authors.forename: N
authors.initials: N
authors.lastname: Watanabe
authors.forename: H
authors.initials: H
authors.lastname: Akita
authors.forename: Y
authors.initials: Y
authors.lastname: Narita
authors.forename: Y
authors.initials: Y
authors.lastname: Kawakami
mesh_terms: D018262:Adenocarcinoma, Clear Cell / Q000473:pathology* / Q000601:surgery; D000328:Adult; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology* / Q000601:surgery; D008297:Male; D013997:Time Factors