Diagnostic cytology: Key techniques and applications in disease diagnosis

Diagnostic cytology involves the examination of individual cell morphology for the purpose of diagnosing and predicting the progression of diseases. It is primarily used because cytological samples are more affordable, easier to collect, simpler to process, and facilitate a rapid diagnosis. Techniques employed in diagnostic cytology include smear preparations (e.g., blood or impression smears), fine-needle aspiration, which incorporates methods such as the woodpecker technique, syringe-attached method, and squash-preparation. Additional techniques include tissue scraping, swabbing, and biopsy. Recognizing basic inflammatory cells, such as neutrophils, eosinophils, lymphocytes, macrophages, and plasma cells, is crucial for the accurate interpretation of cytological samples. For diagnosing neoplastic growth, cytology aids in evaluating the nucleus and cytoplasmic characteristics of the cells. Vaginal cytology is widely used to identify different stages of the estrous cycle in canines. Furthermore, analyzing body fluids, such as synovial and peritoneal fluids, contributes to diagnosing specific conditions through cytological evaluation.