Endocrine Abstracts

Introduction: First assessment of lung tumors is often performed by imaging combined with biopsy. This is necessary for immunohistochemical tumor typing, evaluation of treatment options and prognosis. It has been shown in literature reviews that Endobronchial ultrasound (EBUS) with fine needle aspiration cytology (FNAC) is not inferior in diagnostic quality, but much less invasive than mediastinoscopy of chest laparotomy (1–3). In this case report we will describe the cut-backs of fine needle biopsies in the differentiation of lung tumors.

Case: A 49-years old woman was referred to the pneumology department after incidental finding of a pulmonary nodule in the left lower lobe on a post-operative abdominal CT scan. Further imaging showed additional nodules in the left and right lung. Our patient had no concerning complaints nor did she present with any noticeable clinical red flags. Past medical history included a resected melanoma and auto-immune hypothyroidism, as well as an extensive oncological family history. Bronchoscopy with EBUS-miniprobe guided transbronchial biopsy was performed to assess the nodules. Biopsy using FNAC defined a epithelioid tumor which was classified as a small cell lung cancer. However, post-resection histology proved the tumor to be a carcinoid tumor. Literature review showed a recently published case report with very similar findings (4).

Discussion: Differential work-up of pulmonary malignancies is often made with small biopsy or FNAC. Especially in case of atypical presentation, it is of importance to re-evaluate the working diagnosis with histology of the resected tumor (5). The differentiation between small cell lung cancer and carcinoid tumors based on small biopsy seems often to be inaccurate. This has great implications in choice of therapy and follow-up (6). Through this case, we want to emphasize the shortcomings of FNAC in tumor typing and the importance of tumor type confirmation with post-resection histology.

References: 1. Yasufuku K, Pierre A, Darling G, de Perrot M, Waddell T, Johnston M, et al. A prospective controlled trial of endobronchial ultrasound-guided transbronchial needle aspiration compared with mediastinoscopy for mediastinal lymph node staging of lung cancer. The Journal of thoracic and cardiovascular surgery. 2011; 142(6):1393–400.e1.

2. T B, F. J H. Endobronchial ultrasound: A new innovation in bronchoscopy. Lung India: Official Organ of Indian Chest Society. 2009; 26(1):17–21.

3. Medford AR, Bennett JA, Free CM, Agrawal S. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA): applications in chest disease. Respirology (Carlton, Vic). 2010; 15(1):71–9.

4. Kyritsis I, Krebs B, Kampe S, Theegarten D, Aigner C, Welter S. Erroneous diagnosis of small cell lung cancer based on small biopsies with far-reaching consequences: case report of a typical carcinoid tumor. Journal of thoracic disease. 2017; 9(2):E99–e102.

5. Zheng M. Classification and Pathology of Lung Cancer. Surgical oncology clinics of North America. 2016; 25(3):447–68.

6. Sanchez de Cos Escuin J. Diagnosis and treatment of neuroendocrine lung tumors. Archivos de bronconeumologia. 2014; 50(9):392–6.