DIAGNOSTIC ACCURACY OF AXILLARY ULTRASOUND IN DIAGNOSIS OF METASTATIC AXILLARY LYMPH NODES IN PATIENTS WITH KNOWN BREAST CANCER

Background: Breast cancer is the most frequently diagnosed malignancy among women in Pakistan, with the country having the highest incidence rate in Asia. Accurate assessment of axillary lymph node involvement plays a crucial role in determining prognosis and planning treatment. While ultrasound is a widely available and cost-effective imaging modality for axillary staging, its diagnostic performance remains variable due to operator dependency. This study aimed to assess the diagnostic accuracy of axillary ultrasound using histopathology as the reference standard. Objective: To determine the diagnostic accuracy of axillary ultrasound in diagnosing metastatic axillary lymph nodes among patients with histologically confirmed breast cancer. Methods: This cross-sectional study was conducted at the Dow Institute of Radiology, Dow University of Health Sciences, Ojha Campus, Karachi, from July 1, 2024, to April 1, 2025. A total of 161 female patients aged 25 to 70 years with known breast cancer and clinical suspicion of axillary involvement were enrolled using non-probability consecutive sampling. Axillary ultrasound was performed using a 7.5 MHz linear transducer by an experienced radiologist. Ultrasound-guided core needle biopsy was conducted in cases showing suspicious lymph nodes, and histopathological examination was considered the gold standard. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall diagnostic accuracy were calculated using 2×2 contingency tables. Results: The mean age of participants was 46.57 ± 9.30 years. The average lymph node size was 1.89 ± 0.80 cm. Among 161 patients, axillary ultrasound demonstrated a sensitivity of 95.89%, specificity of 73.33%, PPV of 97.22%, NPV of 64.71%, and an overall diagnostic accuracy of 93.79% in identifying metastatic axillary lymphadenopathy. Conclusion: Axillary ultrasound showed high diagnostic accuracy and sensitivity in identifying metastatic axillary lymph nodes, supporting its utility as a non-invasive tool in the preoperative assessment of breast cancer patients.