[Benign clear cell tumour of the lung (author's transl)]

The benign clear cell tumor of the lung is an uncommon neoplasm. It is often confused, before histological analysis, with metastases. The data of one personal observation are similar to those of 19 other cases of the literature. This tumor which occurs with an equal frequency in adults of the two sexes is often asymptomatic. It is discovered after a systematic x-ray control of the lungs. It is located in the peripheral parenchyma and looks like a round, homogeneous, well delimited opacity. Its evolution is always favourable after surgical excision. The benign clear cell tumour is never identified before pathological study. This neoplasm 1 to 6 cm in diameter consists of a uniform proliferation of clear cells filled up with free of intra-vesicular glycogen. Its cytological and structural features are not the same as those of the other primitive bronchopulmonary tumours having an important clear cell contingent. The histochemical and ultra-structural studies are at the origin of three hypotheses; is the benign clear cell tumor an apudoma, a smooth muscular neoplasm or an adenoma of the terminal bronchioles?