title: Solitary fibroleiomyomatous hamartoma of the lung in a patient without a pre-existing smooth-muscle tumor.
abstract: A solitary well-demarcated tumor was found in the left lung of a 53-year-old man. It was located in the posterior region of the lower lobe just adjacent to, but apart from, the pleura. It was resected by video-associated thoracic surgery. Macroscopically, the tumor was a whitish solid nodule without hemorrhage or necrosis, and it was 1.5 cm in diameter. Histologically, the tumor consisted of a proliferation of fibromuscular tissue in interlacing fascicles in which many tubular or cleft-like epithelial inclusions were involved. The epithelial inclusions showed cystic changes with goblet cell metaplasia in part, but no atypical changes. Other mesenchymal components such as cartilaginous, myxomatous or adipose tissues were not seen. The patient had no history of neoplasm, including smooth-muscle tumor. Thus, we diagnosed this tumor as a "true" fibroleiomyomatous hamartoma, as distinct from so-called fibroleiomyomatous hamartoma or benign metastasizing leiomyoma, which are usually found in the lungs of women who have had hysterectomies, as multiple fibromuscular nodules. We report here this rare case and we review and discuss published reports of fibromuscular tumors of the lung.
authors.affiliation: Second Department of Pathology, Miyazaki Medical College, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan. hitoh@post.miyazaki-med.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Itoh
authors.forename: M
authors.initials: M
authors.lastname: Yanagi
authors.forename: T
authors.initials: T
authors.lastname: Setoyama
authors.forename: K
authors.initials: K
authors.lastname: Shirao
authors.forename: S
authors.initials: S
authors.lastname: Yanagi
authors.forename: H
authors.initials: H
authors.lastname: Kataoka
authors.forename: T
authors.initials: T
authors.lastname: Shimotakahara
authors.forename: M
authors.initials: M
authors.lastname: Koono
mesh_terms: D006222:Hamartoma / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D007889:Leiomyoma / Q000000981:diagnostic imaging / Q000473:pathology*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D018235:Smooth Muscle Tumor / Q000000981:diagnostic imaging / Q000473:pathology*; D014057:Tomography, X-Ray Computed