Myofibroma in the frontal region of the skull with a history of trauma in a 3.5-year-old child – a case report in the context of imaging diagnostics

Abstract

Myofibromas in the orbit are considered very rare. According to literature data, 50% of myofibroma lesions occur in the neonatal period, and most of the remaining cases occur in children under 2 years of age. The diagnosis of myofibroma is possible based on histopathological examination. Morphological characteristics in imaging studies, patient’s age, size of lesions and their number are helpful in making the diagnosis. 
The presented case concerns a 3.5-year-old boy whose parents observed a rapidly growing tumor in the frontal region during a week and a half before the child was admitted to the hospital for further diagnostics. The interview revealed that the boy had suffered a head injury 2 months earlier, in the form of being hit by a swing. Since the injury, the frontal region has been under periodic surgical observation due to a suspected post-traumatic hematoma. The initial ultrasonud examination of the soft tissues of the frontal region revealed a poorly demarcated, non-movable, non-compressible mass with approximate dimensions of 3 x 5 x 5 cm. The lesion was filled with heterogeneous, hypoechoic content (solid or fluid); hyperechoic bands were visible within the lesion near the squamous part of frontal bone, which could correspond to calcifications or bone destruction. The Color Doppler examination did not clearly demonstrate vascularization within the lesion. The patient also underwent a magnetic resonance imaging (MRI) scan of the head, which revealed a tumor in the left frontal region measuring 56 x 39 x 52 mm, with intermediate signal intensity in T1- and T2-weighted images, which was contrast enhanced mainly in the peripheral parts of the lesion and did not show signs of restricted diffusion on diffusion-weighted imaging (DWI) sequence. Frontal craniotomy and left orbitotomy were performed. The tumor was removed from the anterior cranial fossa, left orbit and ethmoid. Fragments of bone infiltrated by the tumor were also removed and cranioplasty was performed. Myofibroma lesion was confirmed histopathologically. Apart from surgical treatment, during the entire treatment at the local clinic, the patient received 5 cycles of cytostatic treatment (vincristine) with good tolerance. 
The authors of this publication are inclined to assume that the injury that occurred in the boy in the described case could have been related to the later appearance of a myofibroma in the frontal and orbital regions. This case also emphases the value of control ultrasound examinations, which are the first and most easily accessible to assess the evolution of post-traumatic changes in paediatric patients.