Congenital peribronchial myofibroblastic tumor: comparison of fetal and postnatal morphology.

Congenital peribronchial myofibroblastic tumor (CPMT) is a solid pulmonary tumor found in fetuses and neonates with pathology characterized by a proliferation of bland spindled cells with or without irregular cartilaginous islands. It has previously been reported in the literature as a fibrosarcoma, leiomyosarcoma, and hamartoma, among other names. Although complications such as fetal hydrops can occur, the prognosis is generally good if the infant can survive long enough for mass resection. We present a case of a CPMT resected by antenatal fetal surgery at 23 weeks in gestation, with additional tumor resected following birth when the infant was 6 weeks of age. The pathology of this lesion showed a marked increase in the cartilaginous component after birth as well as a decrease in cellularity and mitotic activity. This case presents a unique opportunity to examine the progression of a congenital tumor excised by prenatal and postnatal resections.