Investigation of the frequency of meningothelial hyperplasia and its clinicopathological correlation in patients diagnosed with subdural hematoma

Subdural hematomas develop as a result of hemorrhages in bridging veins located within the subdural space, between the dura mater and arachnoid mater. Histopathological examination of surgical specimens from hematoma regions may reveal meningothelial cell hyperplasia secondary to the hemorrhage. This study aims to evaluate the frequency of meningothelial hyperplasia (MH), cell count and size observed in these specimens and to highlight this proliferation which may mimic meningioma in differential diagnosis. Histopathological slides of 68 patients operated for subdural hematoma were retrospectively analyzed. Membrane thickness and the cell count and size of hyperplasia in areas with MH were measured. Associations with clinical parameters such as age, sex, hypertension, diabetes mellitus, and chronic kidney disease, as well as histopathological parameters like granulation tissue and psammoma bodies were investigated. MH was observed in 23 patients (33.8 %) and absent in 45 patients (66.2 %). The meningothelial cell layer count ranged from a minimum of 3 to a maximum of 15, with an average cell count of 9.6. The average size of the MH areas was 482 μm and the mean membrane thickness across all patients was 1.8 mm. Psammoma bodies were observed in 23 patients (33.8 %) and granulation tissue was seen in 25 patients (36.8 %). The presence of MH was found to be associated with increasing age (p = 0.021) but was unrelated to hypertension, diabetes, or chronic kidney disease. However, increased membrane thickness was observed in patients with hypertension (p = 0.029). In conclusion, this study investigated the frequency of MH which is a reactive process in subdural hematoma specimens and further clinicopathological studies are crucial for better understanding meningothelial cells, which are also the origin of meningiomas.