Imaging and Pathological Characteristics of Port-Wine Stain Patients with Tissue Hypertrophy Before Laser Therapy: Retrospective Data

Abstract

Background: Port-wine stain (PWS) patients may simultaneously have accompanied soft tissue hypertrophy. The outcome of laser therapy can be poor. Objective: To study the imaging and histopathological characteristics of PWS patients with facial overgrowth. Materials and methods: We retrospectively assessed the effect of therapy on a subset of PWS patients with facial overgrowth. The degree of hypertrophy and the density of enhanced signals on T1-weighted magnetic resonance imaging (MRI) were independently graded by two radiologists using a quartile scale. Biopsies/resection of tissue deep to the facial muscle was reviewed and compared with flat PWS. Results: Thirty-two PWS patients with facial hypertrophy and 15 patients with flat PWS were included. MRI revealed a statistically significant correlation between the degree of hypertrophy and the density of enhanced signals (3.02 ± 0.92 vs. 2.47 ± 0.69; p < 0.01). Histological features of a subset of patients showed that vascular malformations existed in the dermis and also in the subcutaneous fat and muscle with much larger vessel diameters (fat, 0.048 vs. 0.020; muscle, 0.035 vs. 0.017) and thicker vessel walls (fat, 0.014 vs. 0.006; muscle, 0.010 vs. 0.006) (both p < 0.05). Conclusions: The imaging and pathological findings indicate that capillary malformation in subcutaneous tissue might be a major cause of poor therapeutic effect of laser therapy for PWS. Clinical trial registration no.: ChiCTR1800014278.