title: Contrast-enhanced dynamic magnetic resonance imaging of primary pulmonary leiomyosarcoma.
abstract: An abnormal opacity was found incidentally on chest radiography in a 19-year-old Japanese man with lumbago. Chest computed tomography (CT) revealed a 55 x 40 mm well-defined mass with smooth margins in the lower lobe of the right lung (S6). Contrast-enhanced dynamic CT showed that the lesion was not enhanced, suggesting a cystic lesion, such as a bronchogenic cyst. However, contrast-enhanced dynamic magnetic resonance imaging (MRI) revealed enhancement of the lesion, which had a clear margin and homogenous consistency, suggesting a benign pulmonary solid tumor. Video-assisted thoracoscopic surgery, S6 segmentectomy, was performed, disclosing the lesion to be solid. Histopathologically, the tumor consists of spindle cells with ample eosinophilic cytoplasm arranged in an interlacing pattern. Immunohistochemical staining revealed positive desmin reactivity but was negative for alpha smooth muscle actin and HHF-35 (muscle specific actin), indicating atypical phenotypic differentiation. The lesion was accordingly diagnosed as leiomyosarcoma with low grade malignancy, and right lower lobectomy was performed. The patient has remained free from recurrence for 18 months without any additional chemotherapy or radiation therapy. Contrast-enhanced dynamic MRI should be carried out to facilitate accurate preoperative diagnosis and selection of the correct surgical plan.
authors.affiliation: Department of Pathology, Nagasaki University Hospital, Nagasaki, Japan. toma@nagasaki-u.ac.jp
authors.forename: Tomayoshi
authors.initials: T
authors.lastname: Hayashi
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Tagawa
authors.forename: Kazuto
authors.initials: K
authors.lastname: Ashizawa
authors.forename: Kuniko
authors.initials: K
authors.lastname: Abe
authors.forename: Naoe
authors.initials: N
authors.lastname: Kinoshita
authors.forename: Shin
authors.initials: S
authors.lastname: Tsutsui
authors.forename: Masanobu
authors.initials: M
authors.lastname: Anami
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nagayasu
mesh_terms: D000328:Adult; D003287:Contrast Media / Q000494:pharmacology*; D006801:Humans; D007150:Immunohistochemistry; D007890:Leiomyosarcoma / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology*; D008168:Lung / Q000473:pathology; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D013902:Radiography, Thoracic / Q000379:methods; D020775:Thoracic Surgery, Video-Assisted; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D003287:Contrast Media