Overview
Fine needle aspiration cytology is a minimally invasive diagnostic procedure used to evaluate palpable and accessible mass lesions. It involves aspiration of cells from a lesion using a fine needle, followed by cytological examination of prepared smears. FNAC is widely used for rapid diagnosis of benign and malignant conditions and is commonly applied to breast lumps, thyroid swellings, lymph nodes, and superficial soft tissue masses. With imaging guidance such as ultrasound or CT, deeper lesions can also be sampled safely.
Symptoms
FNAC is performed in patients presenting with lumps, swellings, or masses detected clinically or on imaging. These may be painless or painful and may show features such as rapid increase in size, hardness, fixation, or associated systemic symptoms. Enlarged lymph nodes, thyroid nodules, breast lumps, subcutaneous swellings, and testicular masses are common clinical presentations prompting FNAC. Many lesions may be asymptomatic and detected incidentally.
Causes
The lesions evaluated by FNAC arise from a variety of pathological processes. These include inflammatory conditions, infections, reactive hyperplasia, cystic lesions, benign tumors, and malignant neoplasms. Thyroid swellings may be due to colloid goiter, thyroiditis, or carcinoma. Breast lumps may represent fibroadenoma, cysts, or carcinoma. Lymph node enlargement can result from reactive, granulomatous, or metastatic disease. FNAC helps identify the underlying cellular cause of these lesions.
Risk Factors
Risk factors for conditions diagnosed by FNAC include increasing age, family history of malignancy, hormonal influences, chronic infections, and environmental exposures. Individuals with long-standing nodules, rapidly growing masses, or recurrent swellings are at higher risk of significant pathology. Deep-seated lesions and lesions in vital areas require experienced operators and image guidance to minimize complications.
Prevention
Although the underlying diseases detected by FNAC cannot always be prevented, early evaluation of suspicious lesions helps prevent disease progression and unnecessary surgery. Timely FNAC allows rapid differentiation between benign and malignant conditions, guiding appropriate management. Proper patient selection, aseptic technique, adequate sampling, and expert cytological interpretation improve diagnostic accuracy and patient outcomes.
