[MIM 228 550, 615 293]

Rare disorder of mesenchymal origin, affecting the newborn and infant: the lesions are present at birth or begin before the age of 2 years in the majority of cases. In general sporadic cases but there are rare familial forms. At histology: proliferation of myofibroblasts, which are intermediate fusiform cells between fibroblasts and smooth muscle cells, which gather together in bundles within a substance more or less rich in collagen. The lesion is usually a well-delimited mass of reddish color, organized into 'zones' with a vascularized centre where necrosis occur, and  occasionally calcifications.

One can be distinguish:

-        local or solitary form (75 %): nodule located in the majority of cases at the level of the head, neck and trunk, in skin, muscle or subcutaneous tissue, very rarely in the bone; rarely localization in the liver or pancreas. Nerve compression has been observed.

-        multicentric form: they are

a) a multiple form: multiple tumors of the skin, soft tissue and bone (lytic lesions)

b) a systemic or widespread form: multiple tumors in soft-tissue and bone but also visceral organs: liver, lung, intestine, central nervous system, heart; this form is associated with significant morbidity and mortality.

Evolution: the majority of lesions involute spontaneously after a period of rapid growth. Cases of lethal evolution exist in case of systemic form; in some cases, surgical excision and/or chemotherapy is needed.

Anesthetic implications:

solitary form: based on location; multicentric forms: risk of pathological fracture, check BP (risk of hypertension of renal origin).

References : 

-                Puzenat E, Marioli S, Algros M-P et al. 
Myofibromatose infantile familiale. 
Ann Dermatol Vénéréol 2009; 136: 4: 364-9.

-                 Hatzidaki EG, Giannakopoulou CC. 
Infantile myofibromatosis. 
Orphanet Encyclopedia March 2005.

-                 Brasseur B, Chantrain CF, Godefroid N, Sluysmans T, Anslot C, Menten R, Clapuyt P, Dupont S, Vermylen C ; Brichard B. 
Development of renal and iliac aneurysms in a child with generalized infantile myofibromatosis. 
Pediatr Nephrol 2010 ; 25 : 983-6.

Updated: November 2018