SUMMARY:We present a case of hemifacial hyperplasia in an infant manifesting predominantly as lipomatosis and hemihypertrophy of the maxilla. To our knowledge, there is only 1 other case report in the literature demonstrating the MR imaging features of this condition. Our case was manifest almost exclusively as lipomatosis, largely lacking muscular hypertrophy/hyperplasia. ABBREVIATIONS: BWS ϭ Beckwith-Wiedemann syndrome; HFH ϭ hemifacial hypertrophy; MRA ϭ MR angiography; PHFH ϭ partial hemifacial hypertrophy; THFH ϭ true hemifacial hypertrophy H emifacial hyperplasia is a rare developmental anomaly characterized by asymmetric growth of Ն1 part of the face. In this report of a female child born with facial asymmetry, CT and MR imaging revealed predominantly lipomatosis. The case suggests that hemifacial lipomatosis may be a subtype of partial hemifacial hyperplasia. We discuss the differential diagnosis of HFH and emphasize the importance of screening for embryonal malignancies.
Case ReportA 15-month-old female child presented to our department with rightsided facial fullness (Fig 1). The abnormality was noted at birth, and the child's parents stated that the fullness did not fluctuate in size. The right cheek appeared to grow at a rate similar to the left side. Physical examination was also remarkable for a slightly enlarged right auricle. There were no other significant medical problems. No biochemical or chromosomal abnormalities were detected. The child was otherwise healthy. A sonographic examination showed diffuse right facial adipose hypertrophy but no discrete vascular malformation.CT examination at this time demonstrated predominantly increased fatty tissue on the right side of the face. The distribution of fat was largely in the malar region but also infiltrated the ipsilateral muscles of mastication and the parotid gland and extended into the ipsilateral parapharyngeal fat. The right parotid gland and muscles of mastication had a slightly marbled appearance, and there was enlargement of the right prestyloid parapharyngeal space (Fig 2A). These findings were demonstrated again on a follow-up MR imaging examination 4 months later (Fig 2B).The bony structures of the right face showed slight asymmetry, with hypertrophy of the right maxilla and the right lateral pterygoid plate. There was also subtle enlargement of the right zygoma and the right mandible (Fig 3). Regarding dental development, there was slight early rupture of the right maxillary deciduous canine teeth, and enlargement of the premolar and molar teeth was also noted (Fig 4).MR imaging examination performed as a 6-month follow-up revealed stable and similar findings (Fig 5). No abnormal enhancement was identified. No discrete fibrous capsule to suggest an encapsulated lipoma was seen. The tongue appeared symmetric; however, accurate assessment was difficult because the patient was intubated for the study. Findings of an MRA examination were within normal limits, and no intracranial abnormalities were demonstrated. The child was otherwise dev...