title: Malignant transformation of alveolar adenoma to papillary adenocarcinoma: a case report.
abstract: We present a case involving alveolar adenoma (AA) comprising a malignant component. An 83-year-old man was referred with a solitary pulmonary nodule, which was diagnosed as adenocarcinoma (AC) by transbronchial biopsy. Resected specimen after left S1+2 segmentectomy revealed that the tumor comprised two histologically distinct areas-a central multi-cystic area (AA) and a surrounding area (papillary AC). Careful examination clarified that the borderline lesion showed intermediate mindbomb homolog-1 index and cytological atypia with low papillary growth, suggesting the possibility of malignant transformation of the AA. The malignant potential and coexisting lung carcinoma should be considered in evaluating the tumor diagnosed as AA.
authors.affiliation: 1 Division of Thoracic Surgery, Department of Surgery, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan ; 2 Department of Thoracic Surgery, Saiseikai Suita Hospital, Osaka, Japan ; 3 Department of Pathology, Nara Medical University School of Medicine, Nara, Japan ; 4 Department of Respiratory Medicine, Saiseikai Suita Hospital, Osaka, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Okada
authors.affiliation: 1 Division of Thoracic Surgery, Department of Surgery, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan ; 2 Department of Thoracic Surgery, Saiseikai Suita Hospital, Osaka, Japan ; 3 Department of Pathology, Nara Medical University School of Medicine, Nara, Japan ; 4 Department of Respiratory Medicine, Saiseikai Suita Hospital, Osaka, Japan.
authors.forename: Chiho
authors.initials: C
authors.lastname: Ohbayashi
authors.affiliation: 1 Division of Thoracic Surgery, Department of Surgery, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan ; 2 Department of Thoracic Surgery, Saiseikai Suita Hospital, Osaka, Japan ; 3 Department of Pathology, Nara Medical University School of Medicine, Nara, Japan ; 4 Department of Respiratory Medicine, Saiseikai Suita Hospital, Osaka, Japan.
authors.forename: Motohiro
authors.initials: M
authors.lastname: Nishimura
authors.affiliation: 1 Division of Thoracic Surgery, Department of Surgery, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan ; 2 Department of Thoracic Surgery, Saiseikai Suita Hospital, Osaka, Japan ; 3 Department of Pathology, Nara Medical University School of Medicine, Nara, Japan ; 4 Department of Respiratory Medicine, Saiseikai Suita Hospital, Osaka, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Abe
authors.affiliation: 1 Division of Thoracic Surgery, Department of Surgery, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan ; 2 Department of Thoracic Surgery, Saiseikai Suita Hospital, Osaka, Japan ; 3 Department of Pathology, Nara Medical University School of Medicine, Nara, Japan ; 4 Department of Respiratory Medicine, Saiseikai Suita Hospital, Osaka, Japan.
authors.forename: Sumito
authors.initials: S
authors.lastname: Choh
authors.affiliation: 1 Division of Thoracic Surgery, Department of Surgery, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan ; 2 Department of Thoracic Surgery, Saiseikai Suita Hospital, Osaka, Japan ; 3 Department of Pathology, Nara Medical University School of Medicine, Nara, Japan ; 4 Department of Respiratory Medicine, Saiseikai Suita Hospital, Osaka, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Shimada
authors.affiliation: 1 Division of Thoracic Surgery, Department of Surgery, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan ; 2 Department of Thoracic Surgery, Saiseikai Suita Hospital, Osaka, Japan ; 3 Department of Pathology, Nara Medical University School of Medicine, Nara, Japan ; 4 Department of Respiratory Medicine, Saiseikai Suita Hospital, Osaka, Japan.
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Inoue
keywords: Alveolar adenoma (AA); adenocarcinoma (AC); lung cancer; malignant transformation