复发性呼吸道乳头状瘤病 (RRP) 通常是良性的，是一种以复发性乳头状瘤（疣样病变）为特征的难治性疾病。虽然它最常见地涉及上呼吸道的粘膜上皮层，但在极少数情况下，它也可能涉及肺实质。 RRP 具有恶变的风险，最常见的是非小细胞鳞状肺癌。在此，我们介绍一名 32 岁孕妇的病例，她既往有 RRP 病史，在产后不久出现轻度呼吸窘迫。这促使胸部影像学检查显示右下叶密度低，伴有广泛的肺门和肺门周围淋巴结肿大。支气管标本的组织病理学显示鳞状细胞癌，100% 表达程序性死亡配体 1 (PD-L1)。患者胎盘的肉眼检查显示多个棕褐色结节，经组织病理学检查证实为从肺转移的鳞状细胞癌的多灶性区域。该患者接受了分期正电子发射断层扫描 (PET) 扫描，结果显示右肺中叶和下叶存在代谢亢进区域，右侧气管旁区域有活力，左乳房有增强病变。乳腺病变活检也呈鳞状细胞癌和 PD-L1 阳性。她被诊断患有 IVB 期（T1c、N3、M1c）非小细胞鳞状肺癌，并开始服用派姆单抗。在对治疗产生最初的混合反应后添加卡铂和紫杉醇。该患者不遵守更新的治疗方案以及门诊随访。重新分期 PET 扫描显示对修改后的免疫疗法/化疗方案的反应不足。最终，她在初次诊断后一年半内去世。乳头状瘤病变恶变为鳞状细胞癌的情况很少见，并且转移至乳腺和/或胎盘的情况也极为罕见。据我们所知，这是首例报告的 RRP 患者鳞状细胞肺癌胎盘和乳腺转移病例。版权所有 © 2023，Gogineni 等人。

Recurrent respiratory papillomatosis (RRP), which is usually benign, is an intractable disease characterized by recurrent papillomas (wart-like lesions). Although it most commonly involves the mucosal epithelial lining of the upper respiratory tract, on rare occasions, it can also involve lung parenchyma. RRP carries the risk of malignant transformation, most often to non-small-cell squamous lung cancer. Here, we present the case of a 32-year-old pregnant female with a past medical history of RRP who developed mild respiratory distress during her immediate postpartum period. This prompted imaging of the chest which revealed right lower lobe hypodensities with extensive hilar and perihilar lymphadenopathy. Histopathology of the bronchial specimen showed squamous cell carcinoma with 100% programmed death-ligand 1 (PD-L1) expression. Gross examination of the patient's placenta showed multiple tan-colored nodules which was confirmed on histopathological examination as multifocal regions of squamous cell carcinoma metastatic from the lung. The patient underwent a staging positron emission tomography (PET) scan which showed hypermetabolic regions in the right middle and lower lobes of the lung, with avidity in the right paratracheal region and an enhancing lesion in the left breast. Biopsy from the breast lesion was also positive for squamous cell carcinoma and PD-L1. She was diagnosed with Stage IVB (T1c, N3, M1c) non-small-cell squamous lung cancer and was started on pembrolizumab. Carboplatin and paclitaxel were added after an initial mixed response to therapy. The patient was non-compliant with her updated treatment regimen as well as with outpatient follow-up visits. A restaging PET scan demonstrated an inadequate response to the amended immunotherapy/chemotherapy regimen. Ultimately, she passed away within one and a half years of her initial diagnosis. Malignant transformation of papillomatous lesions into squamous cell cancer is infrequent, and the occurrence of metastasis to the breast and/or placenta is exceptionally rare. To our knowledge, this is the first reported case of placental and breast metastasis of squamous cell lung cancer in a patient with RRP.Copyright © 2023, Gogineni et al.