Multicentric infantile myofibromatosis: two perinatal cases.

Infantile myofibromatosis, the most common fibrous tumor of infancy, occurs in solitary, multiple, and generalized forms, with similar histology but different clinicopathologic and prognostic implications. This entity is a mesenchymal disorder characterized by the proliferation of fibrous tumors in the skin, muscles, viscera, bones, and subcutaneous tissues. Visceral lesions are associated with significant morbidity and mortality, generally within the first few months of life. They lead to failure to thrive, to infection, hemorrhage, or to the obstruction of vital organs. We describe two cases of multicentric myofibromatosis with significant in utero lesional growth, resulting in one fetal demise and one post-natal demise. To the best of our knowledge, this is the first report of a fetal death secondary to infantile myofibromatosis.