Surgical Pocket Cases. The smallest, left, is also known as 'Vest Pocket Case'. c., clockwise, from top, 825, 1850, 1880. The lancet was the most common instrument found in the Pocket Case. Lancets took many forms, such as: scalpel, Bistoury, tenotome, tenaculum, currette, gum lancet, metacarpal saw, vaccinating thumb lancet, etc. Some were single ended, other instruments double ended; most with shell handle.