MESENCHYMAL HAMARTOMA OF THE CHEST-WALL IN INFANTS AND CHILDREN - A CLINICOPATHOLOGICAL STUDY OF 5 PATIENTS

Mesenchymal hamartoma of chest-wall is a rare benign lesion that has v aried histological characteristics and usually occurs during early inf ancy. We report the histological characteristics of mesenchymal hamart oma found in five patients aged respectively 25 days, 5 months, 8 mont hs, and 4 and 8 years at presentation. Two patients presented with res piratory distress, two with an asymptomatic chest-wall mass, and one w ith a deformity of the left chest wall. Surgical resection was perform ed on four patients and a biopsy only in one patient. Overall, the tum ors were well delineated, lobulated, tan to reddish in color, and on s ection showed blood-filled cystic spaces with interspersed small islan ds of cartilage and fibrous tissue. Histological analyses demonstrated mixtures of bone trabeculae with spindle-cell stroma, chondroblast-li ke proliferation, mature and immature hyaline cartilage, and aneurysma l bone cyst formation. All patients are alive and well without evidenc e of disease. Despite the alarming clinical and histologic presentatio n, mesenchymal hamartoma of the chest wall is a non-neoplastic benign lesion.