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.
METHODS: 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.

UNASSIGNED: Myofibromas are benign soft tissue tumors commonly encountered in infancy and childhood. Developing usually within the first two years of life, they can be multicentric and involve deep visceral organs.
UNASSIGNED: We present the rare occurrence of a solitary orbital myofibroma in an adult patient. The clinical, histopathologic and immunohistochemical findings of the tumor are documented.
UNASSIGNED: A comprehensive review of pediatric and adult orbital and periocular involvement by myofibroma is presented. Its characteristic pathologic and molecular findings are reviewed.
UNASSIGNED: Myofibromas are uncommon but important tumors that can occur in the head and neck region, including the orbit. Seen more often in children, they can rarely be encountered in adult patients. Diagnosis is possible with a panel of immunostains and molecular analysis can be further confirmatory.

Infantile myofibroma is a rare benign mesenchymal tumor that presents as solitary or multiple lesions (myofibromatosis) in the skin, soft tissue, bone, or internal organs. It most commonly affects the head and neck of infants and young children, but it can also affect adults. Intracranial involvement is reported to be extremely rare, and its clinical picture has been poorly characterized. Recently, it has been demonstrated that germline and somatic mutations in the platelet-derived growth factor receptor beta (PDGFRB) are associated with familial infantile myofibromatosis. We report a case of infantile myofibromatosis with predominant posterior fossa extradural involvement in a 14-year-old adolescent girl with a confirmed mutation in the PDGFRB gene.