Shrinking pleuritis with atelectasis.

During a 10-year period 28 patients with shrinking pleuritis with atelectasis (SPA) were observed and operated upon. This lesion has been given different names in the literature, for instance rounded atelectasis, pleuroma, pulmonary pseudotumour, and lung folding. All patients except two were operated upon because of a diagnosis of pulmonary tumour. However, at operation no tumour was found. The aetiology and pathogenesis of SPA are discussed on the basis of X-ray, operative, and histopathological findings. In 1966 Blesovsky' described three patients who were operated upon because of suspected pulmonary tumour. At operation no tumour was found but a thick fibrous membrane covered part of the lung. The underlying parenchyma was atelectatic but when the membrane was stripped off, the lung expanded completely and looked normal. Similar cases were described by Hanke2 in 1971 and Kretzschmar3 in 1975. They collected seven and five cases respectively and called the lesion rounded atelectasis. Other reports have since been published.4-10 The diagnosis in the reported cases was made by X-ray and was not always verified by operation or histopathological examination. Radiologically, the lesion is characterised by a rounded or lobulated mass under the visceral pleura with adjacent pleural thickening and with vessels and bronchi curling into it like a "comet tail" (figs 1-3). In many cases the radiological findings are sufficiently typical to allow the diagnosis to be made with confidence. The aim of this paper is to present a series of patients with this lesion, which we have called shrinking pleuritis with atelectasis (SPA), and to discuss its aetiology and pathogenesis.