A biopsy sampling device comprises a handle with a flexible cannula extending from the handle. The flexible cannula includes: an inner catheter, which defines an opening in a lateral wall surface thereof, and further defines a central lumen in fluid communication with the opening an outer catheter positioned around and moveable relative to the inner catheter and a cutting element positioned at a distal end of the outer catheter. The flexible cannula is configured such that a vacuum can be applied through the central lumen of the inner catheter to create a suction that draws a piece of tissue into the opening defined in the lateral wall surface of the inner catheter. The handle is configured to move the inner catheter relative to the outer catheter, such that the cutting element shears and severs the piece of tissue that has been drawn into the opening.