Vet360 Vet360 Vol 05 Issue 04 - Page 7

CPD ACCREDITED ARTICLE Size The single most important variable affecting the likelihood of getting a diagnostic biopsy is specimen size. Small specimens (endoscopic, rhinoscopic, Tru-cut etc.) are highly susceptible to crush artefact. Because such small pieces of tissue may not include diagnostic tissue and in addition can be a challenge to properly orientate in the cassette, very small pieces often produce non-diagnostic biopsies. Large specimens such as amputations, splenectomy’s, large subcutaneous masses etc. resist crush artefacts, but are susceptible to poor fixation. It is important to bread slice such large specimens and then select the interface between abnormal and normal tissue and then subsample different looking areas of tissue for submission. As a general rule the larger the mass the more subsample should be taken. Splenic masses should include at least 4 to 6 pieces. The margin principal Surgeons should always tag what margin is important and note this on the submission form. A common problem is when multiple masses are included in the same jar without being marked. Signalment, history and description of the lesions Histopathology evaluates only a tiny fraction of the affected tissue. In order to fully orientate pathologist and facilitate a total patient evaluation, clinicians and the practice staff must describe what they saw. Descriptive pathology is a skill that veterinarians obtained from vet school, but these skills are frequently lost due to disuse. Again, this comes back to poor communication between pathologists and clinicians, which ignores the important principles that descriptive pathology provides to both parties. With the emergence of sophisticated imaging techniques, clinicians are starting to see the value of descriptive pathology skills. What clinicians see is extremely important in case management and of enormous value to the pathologist in interpreting their biopsies. Pathology is not just for autopsies and it’s not just for pathologists anymore either. lead them into making the wrong diagnosis. Digital pathology has provided clinicians with a very useful and helpful tool to assist with gross description of the lesions. Signalment and history Many clinicians are still under the wrong impression that if they tell the pathologist anything it will bias him or her in their decisions. Such an approach frequently leads to serious errors in medical judgment and mis-diagnosis. If the goal of the biopsy is to fool the pathologist, then tell them nothing. If the goal of the biopsy is to get an accurate diagnosis quickly then tell the pathologists what you know or think. The submission form This is a critical document in solving many of the communication problems of surgical pathology. A good form is one that is 100% dedicated to the biopsy. Remember on this form to give your pathologists the what 4!! • • • • What did you see? What did you do? What do you think? What do you want? The 5 important descriptive elements that should be included on every oncology submission form are the following: 1. Signalment – species, age, breed, sex (intact or not). 2. Clinical or historical daughter – pertinent to the case, brief and to the point (1 to 2 lines). 3. Precise location of the lesion or origin of the sample. 4. Descriptive characteristics – size, colour, shape, distribution. 5. Clinicians thoughts – differential diagnoses, rule out’s. References 1. King J M, Roth, L, Dodd, D C & Newson, M E. 2005. The Necrop- sy Book. 4th edn, Charles Louis Davis Foundation of Comparative Descriptive pathology for biopsy specimens The purpose of the gross description in surgical pathology is to orientate the pathologist reading the histopathology slide and to verify what was received at the laboratory. Description should be brief and to the point and include information pertaining to size, colour, location and distribution. Remember to describe what you see as though you were speaking to a blind person, because effectively the pathologist is unsighted to what you are seeing on the patient. Take photographs and attach to the request. If you do not share this information with them, you may Pathology, Washington. 2. Maxie, M G. 2016. Pathology of Domestic Animals. 6th edn. Saunders Elsevier, St Louis. 3. McGavin, M D & Zachary, J F. 2016. Pathologic Basis of Veteri- nary Disease. 6th edn. Mosby Elsevier, St Louis. 4. Meuten D J. 2017. Tumours in domestic animals 5th edition. Wiley Blackwell, Ames, Iowa. 5. Stromberg P C. 2009. The principles and practice of veterinary surgical pathology. Charles Louis Davis Foundation of Compara- tive Pathology and American College of Veterinary Pathologists. Monterey, California. Issue 04 | SEPTEMBER 2018 | 7