PRIMARY TYPICAL CARCINOID OF THE PLEURA: A RARE INCIDENTAL FINDING

Abstract

SESSION TITLE: Disorders of the Pleura 1 SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/09/2018 01:15 pm - 02:15 pm INTRODUCTION: Carcinoid tumors are a rare occurrence of the thoracic cavity, constituting roughly 0.5 to 2.5% of all pulmonary neoplasms. This case discusses an incidental finding of a primary pleural carcinoid in a patient presenting with spontaneous pneumothorax requiring operative management. CASE PRESENTATION: A 73 year old male with a history of COPD presented with a shortness of breath and was transferred to our facility for a persistent spontaneous right pneumothorax. A CT scan was obtained showing multiple bilateral emphysematous blebs, but no pulmonary or chest wall lesions (Figure 1). The patient was taken to the operating room for a right VATS, partial pleurectomy, and talc pleurodesis after a persistent pneumothorax despite multiple chest tubes. Intraoperatively, no abnormalities were noted in the pleura or chest wall at the time of pleurectomy. Two chest tubes were positioned intraoperatively and placed to waterseal on POD3. They were removed on POD5 and patient was discharged POD7. The parietal pleural specimen was described as an irregularly shaped yellow membrane measuring 14.5X0.5X0.1 cm. There were no gross lesions. Microscopy revealed a well differentiated neuroendocrine carcinoid tumor with a maximum diameter of 3mm. Nests of neuroendocrine cells were present and stained positive for CD-56, CK7, synaptophysin, and CEA. ERG, CK20, WT-1, cam 5.2, TTF-1, CDX-2, and calretinin were negative (Figure 2). Follow-up PET-CT at clinic revealed no evidence of residual disease (Figure 3). DISCUSSION: The most common primary location of carcinoid tumors is the small intestine (30.4%), followed by pulmonary (29.8%) and colon (9.2%). A majority of reported pleural cases are of metastatic disease. Therefore, primary pleural carcinoid disease is a rarity. CT imaging can identify thoracic or gastrointestinal primary carcinoid tumors. In a retrospective review of 50 patients with carcinoid syndrome, Moss et al. identified pleural thickening in nine patients, of which 4 had a primary tumor. Presentation of these patients with primary pleural carcinoid is usually due to mass effect or as an incidental finding on imaging. In this case report, the patient was found to have a 3 mm focus in a pleurectomy specimen. Given the rarity of primary pleural carcinoid, this finding warranted further investigation to ensure that this was not metastatic disease. CONCLUSIONS: A multidisciplinary approach to these rare cases with pathology and radiology cannot be stressed enough. The first step is to rule out other more common pleural malignancies though a panel of histologic stains. Further imaging, including a PET CT, is suggested to identify FDG avid lesions that can be the primary origin. Reference #1: Bertino EM, Confer PD, Colonna JE, Ross P, Otterson GA. Pulmonary neuroendocrine/carcinoid tumors. Cancer. 2009;115:4434-4441. Reference #2: Townshend AP, Lakshminarayanan B, Ucar AE, Chaudry ZR, Duffy JP. Rare pleural recurrence of typical pulmonary carcinoid tumor 30 years after lobectomy. The Annals of thoracic surgery. 2007;83:1523-1524. Reference #3: Moss SF, Lehner PJ, Gilbey SG, et al. Pleural involvement in the carcinoid syndrome. QJM: An International Journal of Medicine. 1993;86:49-53. DISCLOSURES: No relevant relationships by Ernest Chan, source=Web Response No relevant relationships by Lawrence Crist, source=Web Response No relevant relationships by Rajeev Dhupar, source=Web Response I own stock in this company relationship with Inntuitive SUrgical Please note: $20001 - $100000 Added 03/03/2018 by James Luketich, source=Web Response, value=None, I purchsed my self as an stock holder relationship with johnson and Johnson Please note: $20001 - $100000 Added 03/03/2018 by James Luketich, source=Web Response, value=none, I purchsed myself as an no disclosure on file for Anupama Sharma; no disclosure on file for Diane Strollo