Histomorphological characteristics of non-metastatic lymph nodes in patients with head and neck cancer according to their site in the neck

The prognostic relevance of histomorphologically defined reaction patterns of lymph nodes was demonstrated in head and neck cancer. Till today the lymph node site in the neck has not been taken into account. Therefore histomorphologically defined reaction patterns of non-metastatic lymph nodes in the neck were examined according to their site in the neck. A total of 1188 dissected neck lymph nodes of 32 previously untreated patients with carcinoma of the head and neck region were examined histologically by serial sections and classified into 6 different lymph node levels and 6 histomorphological types. The objectivity of the morphological examinations could be evaluated morphometrically by means of an interactive image analysis system (IBAS) and a more precise definition of the lymph node reaction types could be established. The results of the morphological and morphometrical classifications show a statistically highly significant relationship (p < 0.0001) between the reaction types of lymph nodes and their site in the neck. These findings allow a division of the neck in an upper anterior half with immunologically active lymph nodes and a lower caudal-dorsal half, which contains essentially less immunologically active lymph nodes.