Vascular tumours of the lung are classified according to their cell of origin as haemangiopericytomas, haemangioendotheliomas, or sclerosing haemangiomas (Feldman and Seaman, 1964; Mori, 1968; Tralka and Katz, 1963). Of these three types, sclerosing haemangioma is the most common (Feldman and Seaman, 1964; Mori, 1968; Tralka and Katz, 1963), yet only 18 have been well documented in the English literature (Arean and Wheat, 1962; Edwards and Taylor, 1938; Goorwitch and Madoff, 1955; Haas et al., 1972; Hill and Eggleston, 1972; Liebow and Hubbell, 1956; Magri et al., 1957; Mori, 1968; Rubin et al., 1958; Solomon and Wessely, 1959; Turunen et al., 1957). We are reporting an additional case of pulmonary sclerosing haemangioma, to our knowledge the first in the radiologic literature. An asymptomatic, 40-year-old woman had a routine chest X ray film in March 1975, and a solitary, right lung mass was detected. Sputum culture and cytologic findings were negative. Results of needle biopsy of the mass suggested alveolar cell carcinoma but were not diagnostic. In April 1975, the patient was admitted to our institution for thoracotomy. She had no history of cough, haemoptysis, dyspnoea, or recurrent respiratory infections. Physical examination was unremarkable. Haematocrit was 35%; white blood cell count was 5,900 mm3 with a normal differential. Chest X ray films demonstrated a well-defined, oval, somewhat lobulated, 2-cm mass in the right lower lobe (Fig. 1). On the tomogram, the mass appeared homogeneous, without evidence of cavitation or calcification; no other lesions were seen (Fig. 2).