a modular biopsy , ablation and track coagulation needle apparatus is disclosed that allows the biopsy needle to be inserted into the delivery needle and removed when not needed , and that allows an inner ablation needle to be introduced and coaxially engaged with the delivery needle to more effectively biopsy a tumor , ablate it and coagulate the track through ablation while reducing blood loss and track seeding . the ablation needle and biopsy needle are adapted to in situ assembly with the delivery needle . in a preferred embodiment , the ablation needle , when engaged with the delivery needle forms a coaxial connector adapted to electrically couple to an ablating source . methods for biopsying and ablating tumors using the device and coagulating the track upon device removal are also provided .