Abstract

Well differentiated fetal adenocarcinoma of the lung is a subtype of pulmonary blastoma. In this report, CT-guided fine needle aspiration smears were performed at the right upper lobe of the lung in a 45 year-old male patient who had the smoking history of one pack per day for 25 years. The smears disclosed round, papillary, and tubular patterns of cell clusters. The individual cells had relatively uniform, small to medium sized nuclei without nucleoli, and showed vesicular or eosinophilic cytoplasm with indistinct cell border. The morules were seen in the central area of papillary clusters. They were composed of two cell types, outer single layered cuboidal cellular lining and central three-dimensional cluster of cells simulating fetal lung. These cytologic features need to be differentiated from usual pulmonary adenocarcinoma, carcinoid, and pulmonary blastoma. On histologic findings, the tumor arised in the bronchial epithelium. And the tumor cells had abundant intracytoplasmic glycogen with neuroendocrine feature on histochemical study. In addition, the multiplicity of this tumor is the unique point comparable to the previous reports.

• Keywords: Lung;Well differentiated fetal adenocarcinoma;Fine needle aspiration cytology