Multimodality imaging of extra-nodal lymphoma in the head and neck.

Malignant lymphomas represent approximately 5% of all malignant neoplasms of the head and neck. The head and neck region is the second most frequent anatomical site of extra-nodal lymphomas (after the gastrointestinal tract). Most are non-Hodgkin's lymphomas of B-cell lineage, and overall diffuse large B-cell lymphoma is the most common type. They can present in highly variable appearances in different anatomical subsites in the head and neck. There is little literature on their imaging appearances on different imaging methods including ultrasound, magnetic resonance imaging (MRI), computed tomography (CT), and integrated positron-emission tomography (PET)/CT. The review aims to illustrate the presentation of histopathological-proven extra-nodal lymphoma in the head and neck using various imaging methods.