Understanding FNAC: A Visual Guide to Cytology

Welcome to our introduction to Fine Needle Aspiration Cytology, or FNAC.FNAC is a minimally invasive diagnostic procedure that uses a thin needle to extract cells from tissue masses or lumps.The procedure uses a very fine needle, typically between twenty-two and twenty-five gauge, which is much thinner than standard needles.During the procedure, the needle is inserted into the target tissue, and suction is applied to collect cells for examination.This technique provides a quick and reliable way to examine cells from various tissue masses.FNAC offers several key advantages in diagnostic medicine.This technique is particularly valuable for examining several types of tissue masses.Now that we understand the basics of FNAC, let's move on to examine the procedure in detail.The FNAC procedure begins with proper patient positioning and clear identification of the target mass.The area is thoroughly sterilized using antiseptic solution in a circular motion.A twenty-two to twenty-five gauge needle attached to a syringe is prepared for the procedure.The mass is immobilized, and the needle is inserted using the rapid excursion technique.Multiple passes are made in different directions while maintaining suction. This maximizes cell collection from different areas of the mass.Once cellular material becomes visible in the needle hub, suction is released before withdrawing the needle.The collected material is carefully expelled onto clean glass slides.The sample is spread evenly using a smooth, steady motion to create a thin, uniform layer.Immediate fixation is crucial to preserve cellular detail. The slides are fixed using a spray fixative or immersion method.After collection, the slides must be stained to enhance cellular details for microscopic examination.Papanicolaou stain highlights nuclear detail and cellular differentiation, while Giemsa stain is excellent for blood elements and microorganisms.Under the microscope, cytologists examine several key cellular features.The key diagnostic features include nuclear to cytoplasmic ratio, chromatin pattern, nuclear membrane characteristics, and background elements.Cell patterns can help distinguish between benign and malignant conditions. Benign cells often form uniform sheets, while malignant cells show more scattered, irregular arrangements.FNAC results are typically categorized into five main diagnostic categories, ranging from non-diagnostic to positive for malignancy.