Figure 1.

Biopsy technique and workflow. (A) Using a grasping needle of the Riechert–Mundinger system, the first biopsy was typically taken in the most distant part of the tumor, and for each consecutive specimen, the next trajectory was moved proximally through the tumor core until the transition zone. (B) When using the Sedan side-cutting needle, the initial biopsy was taken in the transition zone and then further advanced to the tumor core until the tumor margin. The needle was then turned 180° and samples were taken in a step-wise retrograde fashion. (C) Each tumor sample was evaluated under the Pentero 900 Y560 filter for fluorescein uptake. (D) Fluorescein uptake patterns were then correlated with histopathological diagnosis (x = number of total samples per patient).