MRI FINDINGS OF EXTRACAPSULAR SPREAD IN CERVICAL LYMPH NODE METASTASIS

Abstract

The extracapsular spread (ECS) in lymph node metastasis from head and neck cancer is a very important prognostic factor.
However, diagnostic imagings of ECS in lymph node metastasis are rarely mentioned.
We examined the characteristic findings of ECS in lymph node metastasis, using MRI. We studied 96 lymph nodes in 46 patients proven to have metastasis histopathlogically. Fifty-one lymph nodes out of 96 were proven to be ECS histopathlogically, and 45 other lymph nodes were non-ECS metastasis. We evaluated maximal longitudinal nodal length, the incidence of perinodal high intensity area (PNHIA) on STIR sequence and central necrosis with every ECS group and non ECS group. There were statistically significant differences between the ECS group and the non-ECS group in maximal longitudinal nodal length. It was suggested that maximal longitudinal nodal length may be a criterion of ECS. As the calculated maximum standard of non-ECS was 31.1mm, we felt that this size may serve as a criterion of ECS.
ECS smaller than our criteria was often found, histologically, in fact. Therefore, we proposed the importance of the PNHIA on STIR sequence. The incidence of this finding in the ECS group was higher than in the non-ECS group, with statistically significant differences. We felt that the presence of PNHIA on the STIR sequence may be a criterion of ECS. The incidence of central necrosis in the ECS group was higher than in the non-ECS group, with statistically significant differences. But, the incidence of this finding in the non-ECS group was also relatively high. It was suggested that this findings is not important criteria.