Cytologic characteristics of pulmonary papillary adenoma. A case report

BACKGROUND: Pulmonary papillary adenoma is a benign pulmonary neoplasm. Previously pulmonary papillary adenoma was described in terms of immunohistochemistry and ultrastructure. However, there are no previous reports describing the cytologic characteristics of pulmonary papillary adenoma. CASE: A 50-year-old male was admitted for evaluation of a coin lesion in the left upper lung field. Radiologic images showed a solid, round tumor approximately 25 mm in diameter in the left upper lung. Transbronchial needle aspiration biopsy (TBNA) was performed, and small numbers of atypical cells were collected. Adenocarcinoma was suggested clinically, and left upper segmentectomy was performed. The histologic diagnosis was pulmonary papillary adenoma. Imprint cytology of the cut surface of the tumor showed tumor cells arranged in sheets that contained scant or vesicular cytoplasm. The nuclei were oval or round, without obvious anisokaryosis, and their chromatin was fine, without hyperchromasia. Cytologically, the nuclei of the tumor cells in the imprint specimen (38.70 +/- 8.69 microns 2) were uniform in size and similar to the atypical cells in the TBNA specimen (38.29 +/- 11.56 microns 2) but significantly larger than the nuclei of the bronchial cells (23.61 +/- 5.98 microns 2) (P < .0001). CONCLUSION: The cytologic appearance of pulmonary papillary adenoma was characterized morphologically and morphometrically. The possibility of cytodiagnosis by TBNA was suggested.