Cartilage-containing tumours of the lung. Relationship between the purely cartilaginous type (chondroma) and the mixed type (so-called hamartoma): an unusual case of multiple tumours.

An unusual case is reported of a woman aged 27 years who presented with four intrapulmonary cartilage-containing tumours which were resected from the left lung. The appearance of two new shadows in the chest several years later suggested that two of the resected tumours had recurred. Three of the four resected tumours consisted entirely of cartilage and bone and other connective tissues. The fourth tumour, although consisting almost entirely of cartilage and connective tissue, also contained epithelial tissue in the form of two small clefts, one in the periphery and the other in a connective tissue septum between the lobules of cartilage of the tumour. These tumours are regarded as a variation of the more typical cartilage-containing tumour of the lung which contains many spaces lined by respiratory epithelium and is regarded as a neoplasm arising in the connective tissue beneath the mucosa of a small bronchus with subsequent expansion into its lumen and enclosing spaces lined by the mucosal epithelium during its eccentric growth. The tumours consisting almost entirely of cartilage without spaces lined by epithelial cells are thought to expand into the adjacent lung tissue and not into the bronchial lumen. Therefore there is no inclusion of respiratory epithelium from the mucosa of the bronchus of origin.