Embolic Stroke in a Patient With Lung Mass

Abstract

INTRODUCTION: We report an unusual case of embolic stroke in a middle-aged male. CASE PRESENTATION: A 63-year-old male smoker presented to an outside hospital with aphasia, headache, and blurry vision. Initial head CT revealed a hypodense lesion in the right temporal lobe. MRI of the brain showed areas consistent with multiple acute or subacute infarcts in the right temporal and occipital regions and left temporal and cerebellar regions. A transesophageal echocardiogram revealed a large (36 x 6 mm) pedunculated echogenic left atrial mass, adjacent to the posterior leaflet of the mitral valve and prolapsing into the left ventricular outflow tract. The patient was transferred to our hospital for further evaluation. A Chest radiograph revealed a 4.3 cm left lower lobe mass. A CT of chest confirmed a 3.7 x 3.8 cm lobulated mass in the superior segment of the left lower lobe. A CT-guided transthoracic needle biopsy showed abundant necrosis with malignant appearing epithelial and chondroid cells. A PET scan revealed intense uptake of the mass with a maximum SUV of 6 and linear extension of activity from the mass toward the left atrium corresponding with the course of the inferior pulmonary vein. There was no evidence of distant metastasis. The left atrial mass along with the left inferior pulmonary vein was excised via sternotomy on cardiopulmonary bypass. Subsequently, a left lower lobectomy was performed by video-assisted thoracoscopy. The pathology revealed high grade malignancy with both epithelial and sarcomatous components, consistent with carcinosarcoma. Immunohistochemical stains show focal positivity of the epithelial component for cytokeratins AE1/AE3, CK5/6 and CK7, and negativity for CK20. The tumor also showed diffuse positivity for vimentin and focal positivity for p63. The patient is awaiting chemotherapy. DISCUSSION: Carcinosarcoma is a rare malignancy representing less than 0.3% of all lung tumors. Carcinosarcomas are extremely aggressive biphasic tumors composed of an admixture of malignant epithelial and sarcomatous components. Carcinosarcomas most commonly present in men in their fifth to seventh decades of life. A strong association with smoking has been observed. Controversy exists as to whether carcinosarcomas represent the collision of two distinct primary tumors or a single tumor derived from a pluripotential cell that undergoes sarcomatous and carcinomatous differentiation. The tumor necrosis that carcinosarcomas commonly undergo makes attempts at percutaneous needle or transbronchial biopsy techniques difficult. Patients with carcinosarcomas have a poor prognosis. The median duration of survival after diagnosis is six months, with 6 percent of patients surviving five years. Patients should be considered for curative resection whenever possible, although extension to regional lymph nodes portends a poor surgical result. The value of adjuvant radiation therapy or systemic chemotherapy for patients with unresectable disease is unclear. CONCLUSIONS: To our knowledge, this is the first case of a carcinosarcoma of the lung with vascular invasion of the inferior pulmonary vein and left atrium and presenting as an embolic stroke. This case demonstrates that an accurate preoperative diagnosis of carcinosarcoma of the lung is rarely made because of the difficulty in sampling both histologic components of the tumor.