Endoscopic Biopsy of Intra- and Paraventricular Brain Lesions: Practical Advantages and Clinical Experience

<i>Background and Objectives</i>: Endoscopic biopsy of brain lesions plays an important role in the management of intra- and periventricular lesions. While the diagnostic yield of this technique has been reported with varying success across studies, its outcome is likely influenced by specific technical nuances of the procedure. However, the relationship between these technical factors and diagnostic accuracy remains understudied in the current literature. We aim to describe the procedural rationale, key anatomical considerations, and technical nuances of the endoscopic biopsy of intra- and paraventricular brain lesions, comparing standard tissue forceps with a side-cutting biopsy needle technique. <i>Materials and Methods</i>: We conducted a ten-year single-center, retrospective study of patients who underwent endoscopic biopsy for intra- and paraventricular brain lesions between January 2014 and December 2024. Patients were divided based on the biopsy technique used: the first group of 11 patients was treated using a side-cutting biopsy needle from the center of the lesion, while the second group of five patients underwent tissue sampling with standard endoscopic tissue cup forceps. The study evaluates and compares both approaches in terms of safety and diagnostic accuracy. <i>Results</i>: Endoscopic visualization enabled direct assessment of the biopsy site in both groups. Histopathological diagnoses were successfully obtained in all cases with a side-cutting biopsy needle (11/11, 100.0%), and in almost all cases with the cup forceps technique (4/5, 80.0%). In patients with obstructive hydrocephalus, an endoscopic third ventriculostomy (ETV) was performed as the first and therapeutic step in all procedures and two patients required a shunt procedure. <i>Conclusions</i>: Endoscopic biopsies utilizing a side-cutting biopsy needle strategy offer a promising adjunctive approach for selected intra- and paraventricular brain lesions. This method allows for direct visualization of the intraventricular surface, while the use of a needle biopsy can enhance the likelihood of obtaining diagnostically representative tissue with a high degree of reliability.