Medical Student, Cooper Medical School of Rowan University, Camden, New Jersey, USA.
Department of Thoracic surgery, Cooper University Hospital, Camden, New Jersey, USA.
Diagn Cytopathol. 2021 Jun;49(6):E234-E237. doi: 10.1002/dc.24686. Epub 2020 Dec 21.
Malignant mesothelioma, a neoplasm arising within the serosal surfaces, has been linked closely to asbestos exposure. We present a case of 72-year-old male with a 27 year work-related history of asbestos exposure who presented with dyspnea. Chest computed tomography scan showed a large, right pleural effusion with compressive right lung atelectasis. Biopsies, subsequent pleurectomy and lung wedge resections revealed epithelioid malignant mesothelioma with associated focal non-keratinizing squamous-cell carcinoma, supported by extensive immunohistochemical stains and molecular studies. The patient was treated with 6 cycles of carboplatin/pemetrexed, showing no new metastases. Seven months post-treatment, the patient presented with progressive dyspnea and large pleural effusions. Bilateral pleural fluid was collected and showed malignant epithelioid cells, morphologically similar to the patient's pleural neoplastic cells. However, the tumor was positive for squamous cells markers and showed BAP1 loss, while negative for mesothelial markers. The findings support the diagnosis of squamous-cell carcinoma and were consistent with the patient's previously diagnosed pleural neoplastic origin. A malignant mesothelioma associated with squamous-cell carcinoma is a rare phenonmenon. To our knowledge, only two case reports are available in current literature. This unique case shows a single pleura tumor differentiating as both malignant mesothelioma and squamous-cell carcinoma. Squamous-cell carcinoma is the predominating malignancy seen within the bilateral pleural effusions, a potential pitfall for cytology specimen diagnosis.
恶性间皮瘤是一种起源于浆膜表面的肿瘤，与石棉暴露密切相关。我们报告了一例 72 岁男性，有 27 年与石棉暴露相关的工作史，出现呼吸困难。胸部计算机断层扫描显示大量右侧胸腔积液，伴有右侧肺不张。活检、随后的胸膜切除术和肺楔形切除术显示上皮样恶性间皮瘤伴局灶性非角化性鳞状细胞癌，广泛的免疫组织化学染色和分子研究支持这一诊断。患者接受了 6 个周期的卡铂/培美曲塞治疗，未发现新的转移灶。治疗后 7 个月，患者出现进行性呼吸困难和大量胸腔积液。双侧胸腔积液采集显示恶性上皮样细胞，形态上与患者的胸膜肿瘤细胞相似。然而，肿瘤鳞状细胞标志物阳性，BAP1 缺失，而间皮标志物阴性。这些发现支持鳞状细胞癌的诊断，与患者先前诊断的胸膜肿瘤起源一致。恶性间皮瘤伴鳞状细胞癌是一种罕见的现象。据我们所知，目前文献中只有两例病例报告。这个独特的病例显示单一胸膜肿瘤分化为恶性间皮瘤和鳞状细胞癌。在双侧胸腔积液中，鳞状细胞癌是主要的恶性肿瘤，这可能是细胞学标本诊断的一个潜在陷阱。
