Histopathologic examination showed skin containing a cyst wall lined by ciliated columnar epithelium and supported by smooth muscle, with some deeper seromucous glands. There was no evidence of malignancy.
Bronchogenic cysts are rare congenital lesions that are derived from the primitive foregut. They are most frequently found in the mediastinum, followed by the lung parenchyma.1- 3 When they occur in the skin or subcutaneous tissue, they are usually noted shortly after birth or in early childhood, most commonly in the region of the suprasternal notch or manubrium sterni. They typically present as asymptomatic nodules that gradually increase in size, commensurate with body growth, and rarely drain mucoid fluid.3,4 They can also be found in the presternum, neck, chin, shoulder, or scapular region, as well as the abdominal wall.
Cystic Swelling Overlying the Upper Sternum in a Teenager—Diagnosis. Arch Dermatol. 2006;142(9):1221-1226. doi:10.1001/archderm.142.9.1221-g