Pediatric Myofibromatosis of the Head and Neck

Abstract

Myofibromatosis is a distinct disorder among the great number of fibrous proliferations occurring in infants and children, with a particular predilection for the head and neck region. These lesions should be clearly distinguished from conventional adult-type fibromatoses (desmoid tumors), which are more aggressive. Most patients have solitary lesions that respond well to conservative surgical excision, whereas a few of these lesions behave more aggressively, requiring several surgical procedures for the management of recurrent or persistent tumor. Many of these lesions show spontaneous regression, suggesting that lesions not affecting vital functions, resulting in growth anomalies, or demonstrating rapid aggressive growth may be managed conservatively.

Infantile myofibromatosis: unusual diagnosis in an older child

“…They emphasized IM as a separate disorder, due to its unique histologic morphology and age of presentation. Still considered by most authors to be rare, clarification of the pathology of IM has led to an increased recognition of this diagnosis [6].…”

“…Morphologically, cells are spindleshaped, arranged in bundles or fascicles and appear intermediate between fibroblasts and smooth muscle cells. Characteristic positive immunoreactivity for vimentin and smooth muscle actin and negative immunohistochemical staining for desmin cytokeratin, CD1a, or s-100 aid in making the diagnosis [6,15]. The microscopic appearance of IM does not mirror its usually benign clinical characteristics or correlate with prognosis.…”

“…Malignant features, such as local invasion, hypercellularity, increased vascularity and necrosis are frequently seen. No cases of metastasis or malignant degeneration have ever been reported [6].…”

“…Conservative surgical excision is recommended by most authors as the primary treatment of all forms of IM, particularly where tumors involve vital structures [6]. However, there are numerous case reports of spontaneous regression and a few suggest observation with close follow-up.…”

“…Surgical morbidity is dependent on the site and extent of resection. Recurrence rates for excised lesions range from 10 to 31% and recurrences have been report as distant as 8-15 years from initial presentation [1,6]. Radiotherapy has no role in treatment.…”