An analysis of the onset and clinical characteristics in cystic lymphatic malformations

ABSTRACT Background This study aimed to investigate and compare the applied treatments and the prognosis between patients with congenital and acquired onset cystic lymphatic malformation (cLM). Methods This study was a retrospective cohort study in a single hospital. Patients with cLM treated at our institution were included in this study, and divided into those diagnosed in utero or at birth (CO) and those diagnosed later after birth (AO) with the acquired emerged lesion. Age, site, and size of the lesion, histological subtype, invasiveness grade of the treatment, and the treatment outcomes were compared. Results In total, 147 patients were included. The CO group (n = 85) received more invasive treatment, with the distribution of treatment grades differing significantly from the AO group (n = 62, p = 0.005). cLMs were mainly located on the neck (n = 53, 36.1%), followed by the head and face (n = 31, 21.1%), axilla (n = 7, 4.8%), chest wall (n = 18, 12.2%), mediastinum (n = 5, 3.4%), abdominal wall (n = 4, 2.7%), retroperitoneum (n = 4, 2.7%), hip (n = 5, 3.4%), arm and hand (n = 8, 5.4%), and leg and foot (n = 12, 8.2%). No significant between-group difference was found in terms of the distribution of the main lesions ( p = 0.45). Macrocystic LM was more frequent in the AO group, with a significantly different subtype ratio ( p = 0.02). The frequency of lower-grade treatment was significantly higher in the macrocystic LM subtype in the AO group ( p < 0.001), and this group had a significantly higher treatment completion rate ( p = 0.004). During the treatment course, improvement was seen in 72.9% and 71.0% of patients in the CO group and the AO group, respectively, indicating no significant difference (p=0.79). Conclusions cLMs that newly appeared after birth tended to be macrocystic and had better outcomes with less-invasive treatment than congenital-onset cLMs. The timing of cLM onset could be a key prognostic factor.