Accuracy of clinical examination versus computed tomography in detecting occult lymph node involvement in patients with oral epidermoid carcinoma

To determine the accuracy of clinical examination versus computed tomography (CT) scanning in detecting positive cervical lymph nodes (N) in patients with epidermoid carcinomas of the oral cavity, 27 patients with epidermoid carcinomas were reviewed.

The patients underwent 40 neck dissections, 20 with N- and 20 with N+ necks histologically. All patients were examined by the same clinician, and all CT scans were read by the same radiologist. Patients with clinical and CT N- necks underwent neck dissection only if the neck had to be entered to resect the primary tumor or if the primary tumor was T3 or T4 with a high probability of microscopic metastasis.

Of the 20 necks that were histologically N-, 16 (80%) were clinically diagnosed as N- and 4 (20%) N+ versus 18 (90%) N- and 2 (10%) N+ diagnosed by CT scan. Of the 20 histologically N+ necks, 12 (60%) were clinically diagnosed as N+ and 8 (40%) N- versus 11 (55%) N+ and 9 (45%) N- diagnosed by CT scan. All lymph nodes diagnosed as N- by both clinical examination and CT scan were less than 1 cm in diameter. Overall, clinical examination of the neck was correct in 28 patients (70%) and the CT scan was correct in 29 patients (73%). Both clinical examination and CT scan were more accurate in diagnosis of N- necks. In 31 necks (78%), the CT and clinical examination were in agreement. Of these, 10 of 10 (100%) were correctly positive. Of the 21 in which both were negative, 14 were histologically N-, and 14 (67%) were correct. Overall, in those cases in which both CT and clinical examination were in agreement, the diagnosis was correct in 24 of 31 (77%).

These results suggest that there is no significant difference in the accuracy of clinical examination versus CT scanning in detecting both positive and negative cervical nodes. When both CT and clinical examination agree, positive cervical nodes are almost always correctly diagnosed. However, one third of the negative cervical nodes were incorrectly diagnosed. Improved methods for detecting occult disease are still needed.