Squamous cell carcinoma arising from pulmonary hamartoma.

A 62-year-old woman was admitted for evaluation of a recently increased lung mass which had been regarded as benign for several years. Interestingly, hypermetabolism was noted in only half of the mass while standardized uptake value of the other half was very low on ¹⁸FDG PET/CT suggesting the difference in their nature. Finally, squamous cell carcinoma with hamartoma was found by pathologic examination of surgically removed tumor specimen. As a few reports have suggested that malignant transformation of hamartoma into adenocarcinoma or sarcoma could be possible, this is the first reported case showing that squamous cell carcinoma could also develop from hamartoma. Physicians should be aware of the malignant potential of pulmonary hamartoma.