Occasionally, biopsy samples larger than the biopsy jars are taken. However, it is not helpful or safe to submit the entire sample in formalin. With shipping regulations for air and ground transportation becoming stricter, and with formalin classified as a hazardous chemical, it is becoming difficult to ship large containers of formalin.

Also, from a medical standpoint, large samples immersed in formalin do not fix deeper than 1/4 inch into the tissue. The unfixed center becomes autolytic and nondiagnostic. The best approach would be to take several small sections from the larger mass and submit those in smaller formalin containers. Some larger masses can be sliced serially to allow for better fixation. The only exception to this are intact hearts, which should always be submitted whole, without prior dissection.