Papillary adenoma of the lung is a rather rare tumor. We will present a case of papillary adenoma in the lung with malignant transformation in a 65-year-old male patient. A high dense soft tissue mass was detected in the lateral segment of the right middle lobe by CT examination. Cytologically, the tumor contained the benign cells similar to normal alveolar epithelium and the malignant cells which were significantly enlarged and irregular, crowded, or overlapping. Immunohistochemical staining showed that the epithelial cells were diffusely positive for TTF-1, napsin-A, and CK7, but were negative for p63, p40, CK5/6, CgA, Syn, CD56, and TG. The Ki67 index was about 5%. All of these evidences indicated that it was a case of papillary adenoma with malignant transformation. Thus, it should be noted that more active treatment measures should be taken to treat pulmonary papillary adenoma.

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恶性转化的肺乳头状腺瘤细胞学特征及文献复习

肺乳头状腺瘤是一种相当罕见的肿瘤。我们将介绍一例 65 岁男性患者的肺乳头状腺瘤恶变病例。CT检查发现右中叶外侧段有一高密度软组织肿块。细胞学上，肿瘤内含有与正常肺泡上皮相似的良性细胞和明显增大、不规则、拥挤或重叠的恶性细胞。免疫组织化学染色显示上皮细胞对 TTF-1、napsin-A 和 CK7 呈弥漫性阳性，但对 p63、p40、CK5/6、CgA、Syn、CD56 和 TG 呈阴性。Ki67 指数约为 5%。所有这些证据都表明这是一例乳头状腺瘤恶变。因此，