2020 Volume 59 Issue 6 Pages 273-278
Background : Pulmonary tumorlet (PT) is a non-neoplastic proliferative lesion of the neuroendocrine cells along the bronchial basement membrane, and is often associated with bronchiectasis. To the best of our knowledge, there are only two previous reports of the cytological characteristics of PT. Herein, we report an extremely rare case in which we used touch imprint cytology for the diagnosis of PT associated with bronchiectasis.
Case : A 70-year-old woman was admitted to our hospital with a history of hemoptysis. Chest computed tomography (CT) showed consolidation of a homogeneous nodular opacity in the right pulmonary middle lobe, measuring 10 mm in diameter. We prepared a touch imprint cytology sample using the surgically resected pulmonary specimen. Cytologically, the lesion was provisionally diagnosed as a typical carcinoid (TC). Histopathology indicated bronchiectasis as the background underlying pulmonary condition. Immunohistochemistry showed positive staining of the lesion for CD56, chromogranin A, synaptophysin, and thyroid transcription factor (TTF-1). The Ki-67 index was less than 1%. Based on the above findings, the lesion was finally diagnosed as PT associated with bronchiectasis.
Conclusion : In this case, the diagnosis of PT could be established by histopathology and immunohistochemistry. It is difficult to distinguish PT from TC based solely on the cytological findings, because of similarities in the cell morphologies between the two conditions. Detection of bronchiectasis in the background lung and hypocellularity of the cytological smear, in addition to an awareness of PT, is useful for the cytological diagnosis of PT.
