Infantile
myofibromatosis, the most common fibrous
tumor of infancy, is classified in 2 forms; as a solitary nodule or as numerous, widely-distributed multicentric lesions with or without visceral involvement. Although benign, multicentric
myofibromas are still associated with a high incidence of morbidity and mortality due to the infiltration of critical structures. Herein, we present a case of an infant with aggressive
PDGFRB and NOTCH3 mutation-negative
myofibromas distributed throughout the vascular, respiratory, and gastrointestinal systems. The extensive disease resulted in
pulmonary hypertension,
respiratory failure and gastrointestinal obstruction refractory to
chemotherapy and unamenable to surgical resection. Despite the presence of numerous highly invasive
myofibromas, multiple imaging modalities largely underestimated, or even missed,
tumors found at autopsy. This case demonstrates the limitations of radiographic imaging to assess disease burden in multicentric infantile
myofibromatosis. The postmortem findings of extensive disease far exceeding what was demonstrated by multiple imaging modalities suggests that pediatricians should have a high index of suspicion for undetected
tumors if
clinical deterioration is otherwise unexplained.