Congenital chest wall mesenchymal hamartoma

The case of an infant with mesenchymal hamartoma of the chest wall is presented, and the role of conservative diagnostic and therapeutic intervention is emphasized. A large mass that involved the right hemithorax and chest wall was detected in utero on routine ultrasonographic studies and diagnosed as mesenchymal hamartoma by percutaneous fine needle biopsy at 4 days after birth. The mass did not enlarge after birth, but surgical debulking was necessary at 1 month because of progressive respiratory compromise. Tumor regrowth was noted over the ensuing 8 months, and a second debulking at 9 months has been followed by a 6-year interval without evidence of recurrence.