Comparative Study of Lymph Node Metastasis from Squamous Cell Carcinoma and Non-Squamous Cell Carcinoma on Neck CT

Abstract

Purpose To assess the differential imaging findings of metastatic lymph nodes in squamous cell carcinoma (SCC) and non-squamous cell carcinoma (non-SCC) on neck CT and to facilitate the identification of primary focus before performing a biopsy.

Materials and Methods We retrospectively analyzed 46 patients with SCC and 50 patients with non-SCC who underwent neck CT from January 2006 to January 2011. Patients were divided into two groups; SCC and non-SCC. The total number of lymph nodes was 204 in the SCC group and 530 in the non-SCC group. Two observers were asked to assess the characteristics of abnormal lymph nodes (number, margin types, enhancement patterns, size, bilaterality, calcification, fat infiltration, conglomeration, invasion of adjacent tissue, and nodal distribution). Nodal distribution was evaluated by imaging-based nodal classification on neck CT.

Results Between the SCC group and the non-SCC group except for cases of thyroid cancer, the number of lymph nodes and the number of lymph nodes smaller than 3 cm in the non-SCC group except for cases of thyroid cancer were significantly greater than those in the SCC group (p < 0.05).

Conclusion The number of lymph nodes, the number of lymph nodes smaller than 3 cm, and nodal distribution are helpful in differential diagnosis between SCC and non-SCC before performing a biopsy.