Subpleural lipoma.

Abstract

Lipomas, which are relatively common in the subcutaneous tissues, occur only rarely in the thoracic cavity. In this position, they are usually related to the mediastinum (6, 7, 8, 12). Even rarer is the occurrence of subpleural or parietal tumors unconnected with the mediastinum. Three such cases were treated in The New York Hospital during the past five years. Case Reports Case I (Fig. 1): A 14-year-old white boy was admitted to the hospital because of an abnormal routine chest film, which had been taken two weeks previously. It demonstrated a 4 × 7 × 8-cm. density in the right posterior chest wall, opposite the sixth rib interspace. There was localized widening of the rib interspace with attenuation of the adjacent sixth and seventh ribs. On physical examination, a firm, nontender, 4 × 4-cm. mass was found to the right of the spine at the midscapular level, corresponding in position to the density on the chest film. At operation a large, yellow, fatty, dumbbell-shaped mass was found, extending from outside the chest wall through the sixth interspace into the posterior thoracic cavity. The entire mass was excised, and the pathological report was lipoma. Case II (Fig. 2): A 72-year-old white woman was admitted to the hospital without complaints. Two weeks prior to admission she fell, and roentgenograms were taken of the right shoulder for possible fracture. There was no evidence of bone injury, but a density was fortuitously discovered in the right chest. It measured 2 × 3.5 cm. and was adjacent to the lateral chest wall. Exploratory thoracotomy was undertaken and revealed a yellow, encapsulated, subpleural mass. Its base was in the intercostal space but did not penetrate it. The mass was resected and the pathological report was lipoma. Case III (Fig. 3): A 69-year-old white woman was admitted to the hospital for a retinal detachment. A routine chest film revealed a 3.5 × 4-cm., sharply circumscribed density in the left upper lung field adjacent to the lateral chest wall. A left thoracotomy was performed and a soft subpleural mass was found bulging into the pleural cavity. The mass, which did not penetrate the rib interspace, was completely removed. The pathological report was lipoma. Discussion Heuer (6, 7) divided intrathoracic lipomas into three groups: (a) hourglass tumors consisting of an intrathoracic and extrathoracic mass connected by a thin isthmus perforating the thoracic wall between the ribs; (b) anterior superior mediastinal masses which extend up into the root of the neck, presenting as visible and palpable tumors; (c) wholly intrathoracic masses, which are most commonly related to the mediastinum. Those masses separated from the mediastinum have been designated as subpleural lipomas and may be located beneath the costal or diaphragmatic pleura (2, 13). They are rare in the latter location.