A malignant epithelial neoplasm characterized by the presence of spindle cells and anaplastic morphologic features. Giant cells and a sarcomatous component may also be present. The disease is Monarch Disease Ontology entry MONDO_0006406 (sarcomatoid carcinoma). Also known as: carcinoma, spindle cell, malignant, pseudosarcomatous carcinoma, spindle cell carcinoma, spindle cell carcinoma (morphologic abnormality).