Process of Trephine Biopsy

Trephine biopsy is one of the essential techniques for bone marrow examination. The process of trephine biopsy is not difficult to be done. However, the two principal strategies of fixed trephine biopsy specimen preparation have pros and cons too.

Sometimes, the difficulty of cutting tissue that composed of hard and soft but easily torn bone marrow will be the problems of trephine biopsy. To solve this problem, the specimen is decalcified or embedded it in a substance that can harden the bone marrow. For decalcification, the weak organic acids such as formic acid and acetic acid can be used. On the other hand, the chelation with ethylene diamine tetra-acetic acid (EDTA) also can be applied to decalcify the specimen.

There are many consequences of decalcification and paraffin-embedding of specimen.

i. There will be the shrinkage and loss of cellular detail as the sections become thicker.

ii. The nuclear staining may turn into blur.

iii. Some of the cytochemical activities will be lost. For instance, the chloro-acetate esterase activity will be lost after decalcification of bone marrow with weak organic acid is done.

On the other hand, plastic-embedding techniques are relatively more expensive than paraffin-embedding techniques. Moreover, the technical steps of plastic-embedding techniques are more difficult. Yet, there are many advantages of using this method. Unlike paraffin-embedding techniques, there will be no shrinkage, no loss of cellular detail as well as thinner sections of plastic-embedding techniques. This means that a finer cytological detail can be easily obtained by using plastic-embedding techniques. Furthermore, some of the enzymatic activities can be retained. Although immunological techniques are more applicable to paraffin-embedded than plastic-embedded specimens, excessive background staining is a common problem.

There are various qualities of plastics that can be used for embedding. One of it is methyl methacrylate. This kind of plastic needs a long process and it is not suitable for routine diagnostic laboratories. Another example is glycol methacrylate. Glycol methacrylate is a better choice for plastic embedding techniques.

In conclusion, the process of trephine biopsy is simple but still needs a lot of optimization approaches. We have to be cautious when dealing with the specimens. We have to remember that the sample is very precious. We cannot afford to lose it just because of our careless. Thus, try to do the best!  Stay tuned in Cytogenetics Cancer Research blog.

(Reference: Bone Marrow Pathology written by Barbara J. B., David M. C., Irvin A. L. and Bridget S. W.)