Analysis of the fluid contents of simple bone cyst in the mandible

Description of simple bone cyst (SBC) content has been controversial. This study aimed to assess and give a clearer picture of the SBC cavity contents. Between 2014 and 2016, 19 patients with SBC verified by histopathological examination were included in this study. SBC cavity content was investigated using clinical, radiographic, surgical, and laboratory findings. The difference in components among cavity fluid, blood, and serum was evaluated using a paired sample t-test for statistical analysis. All 19 SBC cases radiographically and surgically revealed a fluid-filled cavity. The patients’ average age was 21.3 ± 13.2 years, with no sex predominance found. SBCs were found mostly in the anterior mandible (n = 12, 63.2%). All lesions were filled with clear straw-colored or blood-colored floods with low concentration. Although the fluid components were similar to those in the blood and serum in the laboratory analysis, the statistical analysis revealed that the fluid components were not significantly different only for eosinophil (p = 0.43) and basophil (p = 0.06) counts as blood components and sodium (p = 0.76), potassium (p = 0.08), and chloride (p = 0.13) concentration as serum components. The results show that SBC is a fluid-filled cavity, with the cavity fluid being more likely similar to serum rather than blood regarding internal components.