PANCOAST SYNDROME DUE TO A HIGH GRADE ANAPLASTIC TUMOR

Abstract

SESSION TITLE: Medical Student/Resident Lung Cancer Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Pancoast tumor is an uncommon type of lung cancer that arises from within the superior sulcus, with most clinical manifestations occurring due to mass effect. Pancoast syndrome describes symptoms that accompany such tumors. Symptoms include shoulder and arm musculoskeletal pain, Horner’s syndrome, and neurological complications of the upper extremities. Non-small cell lung cancers (NSCLC), most commonly adenocarcinoma is a predominant cause of Pancoast syndrome (1). CASE PRESENTATION: A 39-year-old male with a medical history of left-sided pneumothorax secondary to a stab wound and chronic cigar use presented to the hospital complaining of a right neck mass and right arm pain. Physical exam was notable for right supraclavicular lymphadenopathy. Initial labs were remarkable for leukocytosis of 13,200 cells/m3, hemoglobin 11 g/dl, lactate dehydrogenase 1590 IU/L, and ESR 92 mm/h. Neck CT with contrast showed a right side supraclavicular mass with right internal jugular vein thrombosis. Heparin infusion was initiated. Chest CT with contrast showed diffuse emphysematous changes, and a large bulky mass involving the medial right upper lobe and anterior mediastinum, with a mass-effect upon the brachiocephalic vein and superior vena cava consistent with Pancoast syndrome (image 1). Alpha 1 antitrypsin levels were normal. Ultrasound-guided biopsy of the right supraclavicular mass demonstrated a poorly differentiated malignant neoplasm composed of anaplastic cell sheets with extensive areas of necrosis. Immunohistochemical analysis was positive for CD34 and Vimentin (image 2). CT abdomen and pelvis showed multiple retroperitoneal nodal metastases and a right upper quadrant mass abutting the liver and posterior diaphragm. His tumor was inoperable, and palliative chemotherapy was elected. DISCUSSION: Most Pancoast tumors are caused by NSCLC(1), however, other malignancies can be responsible as well. In our patient, this occurred due to a poorly differentiated tumor with immunohistochemistry suggesting a possible mesenchymal origin. Surgery was contraindicated due to extensive local progression and distant metastases. In such patients, Site-specific chemotherapy can be selected based upon molecular testing and identification of the primary site (2). CONCLUSIONS: This case is notable for its rarity due to a poorly differentiated tumor of unknown primary site invaded the lung parenchyma and adjacent structures resulting in Pancoast’s syndrome. In such Cancer of Unknown Primary Site (CUP), empiric chemotherapy is the best treatment option available until further advancements in molecular targeted therapies are achieved (2). Reference #1: Marulli G, Battistella L, Mammana M, Calabrese F, Rea F.Superior sulcus tumors (Pancoast tumors). Ann Transl Med. 2016;4(12):239. doi:10.21037/atm.2016.06.16. Reference #2: Greco FA, Lennington WJ, Spigel DR, Hainsworth JD. Poorly differentiated neoplasms of unknown primary site: diagnostic usefulness of a molecular cancer classifier assay. Mol Diagn Ther 2015; 19:91. DISCLOSURES: No relevant relationships by christian ALMANZAR ZORRILLA, source=Web Response No relevant relationships by Omar Ansari, source=Web Response No relevant relationships by Mauricio Gomez, source=Web Response No relevant relationships by Seth Maxwell, source=Web Response No relevant relationships by Kishankumar Patel, source=Web Response No relevant relationships by Luis Silva, source=Web Response