STAGE IV PULMONARY SARCOMATOID CARCINOMA MASQUERADING AS A PACEMAKER

Abstract

SESSION TITLE: Lung Cancer 1 SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/09/2018 01:15 PM - 02:15 PM INTRODUCTION: Pulmonary sarcomatoid carcinoma (PSC) is a broad term used to describe poorly differentiated non-small cell lung cancers (NSCLCs) with sarcoma or sarcoma-like (spindle and/or giant cell) features. PSC constitutes less than 1% of all lung cancers, but it is the most common pulmonary neoplasm composed of spindled or pleomorphic tumor cells. We present a case of a stage IV PSC with a unique presentation. CASE PRESENTATION: A 75 year-old male presented with progressive worsening of generalized weakness, loss of appetite, subjective weight loss, and increased number of falls over a three-month period. He had a history of Addison’s disease with chronic hyponatremia and a 100 pack-year smoking history. On exam, the patient had a raised area on the left anterior chest wall, initially suspected to be a pacemaker given its shape and location. However, the patient denied ever having any cardiac procedures. Chest x-ray followed by Computed Tomography (CT) of the chest demonstrated a 13.1 x 9.2 x 10.7 cm mass occupying the left hemithorax that involved the mediastinum, touched the aortic arch and pulmonary artery, eroded through the second left anterior rib, and extended into the pectoralis muscles. The percutaneous biopsy specimen showed a malignant spindle cell neoplasm with marked pleomorphism and necrosis. It stained positively for p63, GATA3, and SMA; weakly/equivocally for pancytokeratin; and negatively for CK5/6, CD34, Desmin, SOX10, CK7, EMA, calretinin, and CK20. The patient was deemed too weak to tolerate aggressive systemic chemotherapy. Palliative radiation was initiated. DISCUSSION: PSC carries a significantly worse prognosis than other major types of NSCLCs. Patients are predominantly male smokers, with a mean age of 65 at time of diagnosis. Definitive diagnosis typically requires a resection specimen, which is obtained concomitantly as part of treatment, or not pursued in advanced stages. The main treatments for early-stage PSC are surgical resection and perioperative chemotherapy. No standard targeted or immunotherapy treatments are available. CONCLUSIONS: PSCs are extremely rare, and as such, clinical presentations can be unique. In the case of this patient, one cannot underestimate the importance of a thorough physical exam and history. Reference #1: Franks TJ, Galvin JR. Sarcomatoid Carcinoma of the Lung: Histologic Criteria and Common Lesions in the Differential Diagnosis. Arch Pathol Lab Med. 2010; 134(1):49-54. Reference #2: Maneenil K, Xue Z, Liu M, et al. Sarcomatoid Carcinoma of the Lung: The Mayo Clinic Experience in 127 Patients. Clin Lung Cancer. In press. https://doi.org/10.1016/j.cllc.2017.12.008. Reference #3: Travis WD. Sarcomatoid neoplasms of the lung and pleura. Arch Pathol Lab Med. 2010; 134(11):1645-58. DISCLOSURES: No relevant relationships by Muhammad Habib, source=Web Response No relevant relationships by Manish Patel, source=Web Response No relevant relationships by Thien Vo, source=Web Response No relevant relationships by Grace Wang, source=Web Response