Clinical, imaging, and pathological characteristics of congenital infiltrating lipomatosis of the face.

ABSTRACT

Congenital infiltrating lipomatosis of the face (CILF) is a rare congenital disease of the head and neck region. In this study, the cases of 20 patients diagnosed with CILF were reviewed retrospectively to analyse the characteristics of the disease. The symptoms, signs, and clinical progression were investigated. Radiological changes were analysed according to the distribution of the trigeminal nerve. The pathological features of the fatty facial lesions, jaw hyperplasia, and lingual lesions were further identified. All 20 patients demonstrated hemifacial hypertrophy at birth. None had a family history of the disease. Significant radiological features of CILF (prevalence ≥90%) included thickened buccal subcutaneous fat, palatal submucosal fat, and temporal subcutaneous fat, maxillary tuberosity heteroplasia, and fatty infiltration of the masseteric intermuscular space. With regard to the trigeminal nerve, the frontal branch region (CNV1) was rarely affected, while the maxillary (CNV2) and mandibular (CNV3) branch regions showed considerable changes. Pathologically, CILF was observed to be characterized by the infiltration of mature adipose tissue into the adjacent buccal soft tissue, osteal remodelling surrounded by sheets of mature lipocytes and supporting fibrovascular stroma, and lingual hamartoma. In summary, CILF exhibits distinct characteristics that are related to the regions controlled by the maxillary and mandibular branches of the trigeminal nerve, suggesting that CILF may be associated with early neural development.