Cytological and Biochemical Analyses of Lymphatic Fluid from Patients with Lymphatic Malformations.

Background: Intracystic hemorrhage from lymphangiomas is a common phenomenon in lymphatic malformations (LMs); however, little is known about the associated compositional changes in the lymphatic fluid. Materials and Methods: We prospectively collected lymphatic fluid from children with LMs. Lymphatic fluid was divided depending on the bleeding status into the bleeding and nonbleeding groups. The fluid was subjected to cytological and biochemical analyses to determine protein and cytokine levels. The Mann-Whitney U test was used to compare the two groups. Results: There were significant differences in the levels of interleukin (IL)-6, IL-10, and glucose, and the percentage of white blood cells between the bleeding and nonbleeding groups. There was no significant difference in chlorine and protein content; white blood cell count; and IL-2, IL-4, tumor necrosis factor α, and interferon γ levels between the two groups. Conclusion: Lymphatic fluid is less stable in bleeding LMs than in non-bleeding LMs and is prone to inflammatory reactions. The inflammatory reaction in lymphatic fluid does not stimulate the cytokine storm in blood. The inflammatory reaction due to LMs does not affect the contents of protein and chlorine in lymphatic cyst fluid.