Hamartomas of the chest wall in infants.

Chest wall hamartomas in infancy are rare lesions with distinct clinical, radiologic, and pathologic characteristics. Four cases treated at Children's Hospital of Los Angeles are presented and previously reported cases are reviewed. Chest wall hamartomas arise antenatally and present as hard, immobile masses, which may cause respiratory insufficiency. An extrapleural mass arising from the ribs can be seen radiographically. Histologically, these lesions are hypercellular and consist of a disorganized array of mesenchymal tissues endogenous to the chest wall. Rapid growth may occur, but usually is self-limited. Chest wall hamartomas are usually benign. This series includes the malignant transformation of one of these lesions. En bloc resection is curative, but the large residual chest wall defect frequently results in scoliosis.