Aggressive infantile myofibromatosis with intestinal involvement.

Background: Infantile myofibromatosis (IM) is the most common cause of multiple fibrous tumors in infancy. Multicentric disease can be associated with life-threatening visceral lesions. Germline gain-of-function mutations in PDGFRB have been identified as the most common molecular defect in familial IM.

Case presentation: We here describe an infant with PDGFRB-driven IM with multiple tumors at different sites, including intestinal polyposis with hematochezia, necessitating temporary chemotherapy.

Conclusions: PDGFRB-driven IM is clinically challenging due to its fluctuating course and multiple organ involvement in the first years of life. Early molecular genetic analysis is necessary to consider tyrosine kinase inhibitor treatment in case of aggressive visceral lesions.