umls-concept:C0149925 | skos:definition | CSP: radiosensitive tumor composed of small, oval, undifferentiated cells that are intensely hematoxyphilic and typically bronchogenic.,NCI: An aggressive (fast-growing) cancer that forms in tissues of the lung and can spread to other parts of the body. The cancer cells look small and oval-shaped when looked at under a microscope.,MSH: A form of highly malignant lung cancer that is composed of small ovoid cells (SMALL CELL CARCINOMA).,NCI: A highly aggressive subtype of lung carcinoma characterized by the presence of malignant small cells and necrosis. Metastatic disease is usually present at the time of diagnosis. | lld:umls |