Definition
• A group of poorly differentiated non–small-cell carcinomas of the lung with sarcoma-like differentiation or a component of sarcoma
Clinical features
Epidemiology
• Rare: 1% of all lung malignancies
• Mean age, 60 years (except pulmonary blastoma)
• Male:female ratio, 4:1 (except pulmonary blastoma)
• Strong association with smoking
Presentation
• Patients with peripheral lesions usually present with chest pain
• Patients with central tumors present with signs of obstruction: coughing, hemoptysis, dyspnea, or recurrent infection
Prognosis and treatment
• Surgical resection and chemoradiation therapy
• Worse prognosis than conventional non–small-cell carcinomas
Pathology
Gross
• Peripheral (more common) or central; upper lobes are more likely to be involved
• Solitary large tumor mass with soft to firm cut surface with areas of hemorrhage and necrosis
• Peripheral tumors frequently invade pleura or chest wall
Histology
• Five histological subtypes (each discussed in the following chapters):
• Pleomorphic carcinoma
• Spindle cell carcinoma (also considered a variant of squamous cell carcinoma)
• Giant cell carcinoma
• Carcinosarcoma
• Pulmonary blastoma
Immunopathology/special stains
• When no obvious malignant epithelial component is present in the tumor, multiple keratins (AE1/AE3, CAM5.2, CK5/6), p63, and/or EMA immunostains are needed to prove the epithelial differentiation
Fig 1 Sarcomatoid carcinoma. Gross photograph of large peripheral tumor invading the chest wall, part of which was resected with a lobectomy.
Fig 2 Sarcomatoid carcinoma. Cut surface of the same specimen, fixed in formalin, shows large solid gray-tan tumor.