Distal-type bronchiolar adenoma of the lung expressing p16INK4a - morphologic, immunohistochemical, ultrastructural and genomic analysis - report of a case and review of the literature.

Bronchiolar adenoma (BA) of the lung is a rare benign neoplasm. Because of a chest abnormal shadow indicated by health checkup, a 77-year-old female nonsmoker underwent computed tomography, revealing an 8 mm ground glass nodule in the peripheral field of the right lower lobe. Wedge resection of the nodule was performed, with a frozen diagnosis of primary lung adenocarcinoma. The localized, 8 × 4 × 3 mm-sized, jelly-like mass microscopically revealed a lepidic-growing lesion composed of ciliated columnar cells, mucous cells and basal cells surrounded by mucin pool. Neither nuclear atypia nor mitotic activity was noted. Immunohistochemically, the ciliated, mucous and basal cells were positive for TTF-1 and p16INK4a . Mucous cells were positive for napsin A and focally expressed MUC5AC. MUC6 was negative. Basal cells were positive for CK5/6, p40, p63 and podoplanin. Human papillomavirus genome was undetectable by in situ hybridization. Ultrastructurally, the bronchiolar epithelial tubules consisted of two layers, the inner nonciliated microvillous cells and the outer basal-like cells, and some of the inner cells were filled with mucin granules in cytoplasm. Molecular analysis of the tumor failed to show driver mutations. The final diagnosis was distal-type BA. The postoperative course was uneventful for 6 months.

Medium Term Pulmonary Function Test After Thoracoscopic Lobectomy for Congenital Pulmonary Airway Malformation: A Comparative Study with Normal Control.

INTRODUCTION: Congenital pulmonary airway malformation (CPAM) is a major indication of lobectomy in children. Early lobectomy had been proposed for the advantage of compensatory lung growth. Despite the increasing use of thoracoscopic lobectomy its effect on postoperative lung function was still not well established in the literature. This study was therefore performed to study the result of postoperative pulmonary function test (PFT) on a medium term basis. MATERIALS AND METHODS: All patients who underwent thoracoscopic lobectomy for CPAM between 2006 and 2010 were recruited into the study. PFT was performed 5 years after the operation. Age-matched healthy individuals with similar body size were recruited for PFT as the control group. Demographic data and PFT results were extracted for statistical analysis. Test result less than 80% of predicted value was considered abnormal. RESULTS: Fifteen consecutive patients were identified in the study period, 8 boys and 7 girls. The PFT was performed at a mean age of 9 years. None of the patients had respiratory symptoms. The forced vital capacity (FVC) (99.6% versus 97.0% predicted, P = .56), forced expiratory volume in 1 second (FEV1) (86.0% versus 89.1% predicted, P = .52), FEV1 to FVC ratio (96.6% versus 98.7% predicted, P = .60), total lung capacity (92.5% versus 94.5% predicted, P = .68), and alveolar volume adjusted diffusion capacity of carbon monoxide (106.4% versus 100.4% predicted, P = .35) showed no statistical difference from the control group. CONCLUSION: Patients who underwent thoracoscopic lobectomy have normal lung function 5 years after the operation. Further study is necessary to confirm the long-term result.

Ex Vivo Artifacts and Histopathologic Pitfalls in the Lung.

CONTEXT: Surgical and pathologic handling of lung physically affects lung tissue. This leads to artifacts that alter the morphologic appearance of pulmonary parenchyma. OBJECTIVE: To describe and illustrate mechanisms of ex vivo artifacts that may lead to diagnostic pitfalls. DESIGN: In this study 4 mechanisms of ex vivo artifacts and corresponding diagnostic pitfalls are described and illustrated. RESULTS: The 4 patterns of artifacts are: (1) surgical collapse, due to the removal of air and blood from pulmonary resections; (2) ex vivo contraction of bronchial and bronchiolar smooth muscle; (3) clamping edema of open lung biopsies; and (4) spreading of tissue fragments and individual cells through a knife surface. Morphologic pitfalls include diagnostic patterns of adenocarcinoma, asthma, constrictive bronchiolitis, and lymphedema. CONCLUSION: Four patterns of pulmonary ex vivo artifacts are important to recognize in order to avoid morphologic misinterpretations.

Abundant cartilage formation of congenital pulmonary airway malformation--a case report.

Congenital pulmonary airway malformation (CPAM) of the lung is an uncommon developmental anomaly. We report an unusual case of type 1 CPAM with abundant cartilage in a 5-year-old boy. On chest radiography, a left lung mass was detected incidentally, and tumor resection was performed under the impression of a benign tumor. The pathological examination of the mass revealed abundant cartilage in the walls of malformed bronchioles with partially cystic dilatation. We think that this case represents a cartilaginous variant of CPAM. The cartilaginous variant of CPAM should be differentiated pathologically from other pulmonary neoplasms containing abundant cartilage, such as chondroid hamartoma.