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

Port-wine stain (PWS) patients may simultaneously have accompanied soft tissue hypertrophy. The outcome of laser therapy can be poor. To study the imaging and histopathological characteristics of PWS patients with facial overgrowth. 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. 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;  < 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  < 0.05). 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.