MRI of neck nodes in non-Hodgkin's lymphoma of the head and neck.

The aim of this study is to describe the imaging features of neck nodes in non-Hodgkin's lymphoma (NHL). The MR scans of 61 patients undergoing staging of a primary extranodal NHL of the head and neck were reviewed retrospectively. Those MR images with nodal disease were assessed for (a) the pattern of nodal disease, (b) presence of nodal necrosis and (c) presence of extracapsular neoplastic spread (ENS) and nodal matting. The features of the nodal disease were analysed in relationship to the sites of the primary NHL (palatine tonsil (PT) n=23, nasal cavity (NC) n=24, nasopharynx (NP) n=6, other extralymphatic sites (OES) n=8), and histology (natural killer/T-cell (NK/T) n=26, diffuse large cell (DLC) n=24, other subtypes (OS) n=11). Nodal disease was present in 26 patients (43%) and occurred in NHL of the PT n=16 (70%), NP n=3 (50%), NC n=5 (21%) and OES n=2 (25%) and in DLC n=15 (63%), NK/T n=6 (23%) and OS n=5 (45%). Nodal disease was significantly more frequent in DLC than NK/T lymphomas (p=0.0053). Nodal disease spread in a contiguous fashion in 25 (96%) patients with nodes. Necrosis was present in 7 of 26 (27%) being present in DLC of the PT in 5, NK/T of the NP in one and NK/T of the NC in one. ENS and matting were present in 19 (73%) and 13 (50%) patients with nodes, respectively. ENS was found in DLC, NK/T, OS, NC, NP, PT, OES (11, 4, 4,1, 2, 14, 2, respectively) and matting was found in DLC, NK/T, OS, NC, NP, PT, OES (9, 3, 1, 0, 2, 10, 1, respectively). Nodal NHL spreads in a contiguous fashion and is most commonly associated with DLC lymphoma of the NP and PT in Waldeyer's ring. Extracapsular nodal spread is frequent and found in most histological subtypes especially those arising from Waldeyer's ring. Necrosis is more common than previously believed.