Pulmonary Pathology II Case Studies


CASE 7: Pulmonary Hamartoma


Clinical History:

A 54-year-old man suffered chest injuries in a car accident. X-rays showed no evidence of broken ribs, but an incidental finding of a solitary lung nodule was seen peripherally in the right lower lobe. No prior x-rays were available for comparison. CT scan showed the lesion to be sharply circumscribed, with no associated detectable adenopathy. Percutaneous CT guided fine needle aspiration (FNA) was attempted, but no cellular elements were obtained. He went to surgery, and after a frozen section diagnosis, a segmental wedge resection was performed and the patient spared a lobectomy.

    This is a well-circumscribed nodular lesion composed of mature cartilage with intervening islands of fat, blood vessels, and occasional cystic spaces lined by respiratory epithelium. These lesions are firm to hard and because the soft lung parenchyma behind them gives way, almost impossible to penetrate with a needle to get a sample from. Even had they made the diagnosis by FNA, most likely they would remove it anyway to confirm the diagnosis.

  1. What is the diagnosis? What is the significance?

    2. This is a pulmonary hamartoma. They are benign, harmless lesions, but can be confused on chest x-ray with malignancies.

  2. Where does this lesion arise from?

    3. They are thought to arise as abnormal proliferations of normal elements in the lung.

  3. Why was the surgeon able to shell it out, rather than remove a lobe?

    4. They are benign, never metastasize, and are well-circumscribed and easy to separate from the surrounding lung parenchyma.