INTRACRANIAL INFANTILE MYOFIBROMATOSIS

Infantile myofibromatosis is a proliferative disorder of infancy and e arly childhood characterized by nodular or diffuse growth of lesions t hat are comprised of a mixture of mesenchymal elements within the skin , subcutaneous tissues, skeletal muscle, bone, and/or visceral organs. Although these pseudotumors are considered to be the most common fibr ous ''neoplasm'' of infancy, central nervous system involvement is rep ortedly rare. During the last 7 years, the authors have treated three children with intracranial myofibromas who presented at 6 weeks, 7 mon ths, and 3 3/4 years of age, respectively. Each child had a large calv arial mass that produced significant brain compression despite a pauci ty of neurological signs. On computerized tomography, these tumors wer e isodense to brain tissue, enhanced strongly with intravenous contras t material, and showed smoothly marginated bone erosion without surrou nding sclerosis. On magnetic resonance imaging, the tumors were hypoin tense on T-1-weighted images, with dense enhancement following the adm inistration of intravenous contrast medium, and hyperintense on T-2-we ighted images. At operation, the tumors were highly vascular and appea red to arise from within the leaves of the dura, eroding through the o verlying bone, but not violating the galeal or arachnoidal layers. Two of the lesions were adherent to major dural venous sinuses. Both of t hese lesions were completely resected in continuity with the involved dura, and have not recurred 6 years and 1 year, respectively, postoper atively. However, in one patient in whom the involved dura was not res ected at the initial procedure, the tumor recurred rapidly. A complete excision of the tumor and involved dura was then performed and the pa tient is now recurrence-free, 5 1/2 years after the second surgical re section. All patients tolerated resection well, but two have required cranioplasty for persistent calvarial defects. The surgical experience with these lesions is reviewed and the distinctive features of their clinical presentation, radiographic appearance, operative management, and outcome are discussed.