Malignant Degeneration of Biopsy-Proven Hamartoma to Chondrosarcoma.

Pulmonary hamartomas are benign lesions that are often managed conservatively in the absence of respiratory symptoms. Increasing reports of malignant transformation question if a more aggressive treatment or surveillance practice for these lesions is warranted in adult patients. Herein, we describe a case of a 67-year-old man with a long history of pulmonary hamartoma that demonstrated malignant degeneration into spindle cell malignancy with chondromatous differentiation. This case illustrates the aggressive nature of sarcomatous disease arising from hamartomas and, with a handful of other cases in the literature, points to the question of whether pulmonary hamartomas arising in late adulthood should follow a more intensive treatment or surveillance algorithm given increased concern for malignant potential.