Cytology testing can be a quick and efficient method of obtaining answers to critical animal health questions. However, to get the most value out of cytology, clients must ensure important patient information is relayed at the time of submission. This, coupled with properly collected samples and strong communication between the veterinarian and the Texas A&M Veterinary Medical Diagnostic Laboratory, TVMDL, can give patients the best possible outcomes.
“Cytology is invaluable,” said TVMDL’s assistant agency director for clinical pathology, Julie Piccione, DVM, MS, DACVP. “It’s minimally invasive versus some of our other diagnostic methods and it’s relatively inexpensive.”
Cytology, the evaluation of cells, can quickly provide valuable insights into a patient’s health. Cytologic examination only requires a few cells, rather than a tissue sample. Results can give near-immediate clues to the condition of a patient and help detect multiple health conditions such as infections, cancer, and occasionally immune-mediated diseases.
“With a sample that’s as easy to collect as an impression with a slide or fine-needle biopsy, we can narrow down differentials, guide initial treatment, and sometimes give a definitive diagnosis, which is great,” Piccione said.
Collecting and labeling samples
When collecting samples for a cytology test, proper technique is key. Piccione recommends using a 22-gauge needle to perform fine-needle aspiration (FNA) to extract cells from a mass or lesion, but sometimes a larger needle is necessary.
“If I feel like I’m not getting a good sample with a fine needle and that woodpecker method, I might move up to a 20 gauge or an 18 gauge,” Piccione said.
In addition to proper collection, clients should also label and document the clinical history of samples. Some lesions and populations of cells look identical microscopically, and providing context makes the difference. Clients should also note any gross observations such as whether the mass felt firm or fluid filled. Doing so assists pathologists in better interpreting what they observe under the microscope.
“It helps us to know the clinical history,” Piccione said. “Specifically, what did you sample and why.”
Submitting slides
Following collection, Piccione strongly encourages clients to submit multiple slides as one or two is usually not sufficient for a productive examination. Clients may send up to 10 slides from each source before an additional fee is applied.
TVMDL offers a digital cytology service as another method of submission. This service offers clients the opportunity to submit microscopic pictures taken of their slides before the physical slides arrive at the lab. Results are returned within an hour of submission during business hours.
Although this resource allows pathologists to give a preliminary diagnosis based on the images, digital cytology can also be used for confirmation purposes.
“There are times where clients are submitting those images just to make sure that the sample looks like there are enough cells or before they pay for a shipping fee,” Piccione said. “So, we do have clients use it to view their slides and get that information before the patient goes home.”
Detailed instructions for how to use the digital cytology service on the TVMDL website.
Interpreting results
Upon receiving the results of a cytology test, clients should approach the report with careful consideration of their own clinical suspicions and physical exam.
“If the findings don’t match what you are seeing clinically, or if I didn’t quite answer the question that you were looking for, don’t hesitate to call,” Piccione said. “We can talk about it and see if we can get any further considering the full clinical history and my full cytologic impression.”
In addition, Piccione noted the comment section of the report offers additional valuable insight into the interpretation based on the clinical history, the prognosis, and the future steps for the patient.
“Cytology isn’t perfect,” Piccione said. “We know there are limitations to cytology, but there’s a lot of information we can gather if we work together.”
TVMDL encourages questions and thorough communication. Sometimes cytology alone isn’t enough. Results from cytological testing might be paired with other tests such as cultures or even histopathology. It might complete the diagnostic puzzle.
For more information about cytological testing at TVMDL, visit tvmdl.tamu.edu.
