In the experiment group, when suspicious parathyroid glands or lymph nodes were observed, a 22 G needle was applied for in situ puncture at a 45 degree angle. The needle was initially thrust into the gland for 0.2 mm, and then we advanced the needle for another 0.2mm while gently withdrawing the plunger of the syringe and maintaining negative pressure. At this point, there has parathyroid tissue been adsorbed in the needle. Repeat this process in two different directions to guarantee the simple volume.