Discrimination of Metastatic Cervical Lymph Nodes with Diffusion-Weighted MR Imaging in Patients with Head and Neck Cancer

34-year-old man with benign lymphadenopathy (lymphoid hyperplasia) of the bilateral jugulodigastric nodes.

A, Axial T1-weighted MR image shows homogeneous (except for hilum signal intensity) nodes (arrows).

B, Axial T2-weighted MR image shows homogeneous nodes (arrows).

C, Axial fat-suppressed, gadolinium-enhanced T1-weighted MR image shows homogeneously enhanced (except for hilum signal intensity) nodes (arrows).

71-year-old woman with well-differentiated squamous cell carcinoma of maxilla.

A, Axial T2-weighted MR image of metastatic buccinator node (arrow) shows a large, hyperintense necrotic area.

B, Axial diffusion-weighted echo-planar MR image, at b factor of 500 s/mm², of metastatic node (arrow) shows hyperintensity of the node.

C, Axial diffusion-weighted echo-planar MR image, at b factor of 1000 s/mm², of metastatic node (arrow) shows nodal signal intensity with a central hypointense area. A large reduction in signal intensity on the image at b 1000 s/mm² compared with the image at b 500 s/mm² results in an elevated ADC (0.410 × 10⁻³ mm²/s).

20-year-old man with benign lymphadenopathy in neck.

A, Axial T2-weighted MR image shows an inflammatory jugulodigastric node (arrow) with homogeneous signal intensity.

B, Axial diffusion-weighted MR image at b factor of 500 s/mm² of benign lymphadenopathy (arrow) shows homogeneous hyperintensity.

C, Axial diffusion-weighted echo-planar MR image at b factor of 1000 s/mm² of benign lymphadenopathy (arrow) shows a defined area of hyperintensity. An intermediate reduction in signal intensity on the image at b 1000 s/mm² compared with the image at b 500 s/mm² results in a moderate ADC (0.335 × 10⁻³ mm²/s).

56-year-old woman with diffuse large B cell lymphoma.

A, Axial T2-weighted MR image shows lymphoma in jugulodigastric node (arrow) with homogeneous signal intensity.

B, Axial diffusion-weighted echo-planar MR image at b factor of 500 s/mm² of nodal lymphoma (arrow) shows hyperintensity.

C, Axial diffusion-weighted echo-planar MR image at b factor of 1000 s/mm² of nodal lymphoma (arrow) shows a defined area of hyperintensity. A small reduction in signal intensity on the image at b 1000 s/mm² compared with the image at b 500 s/mm² results in a low ADC (0.258 × 10⁻³ mm²/s).

Graph (box plots) shows ADCs of metastatic nodes, nodal lymphomas, and nodes with benign lymphadenopathy. The horizontal line is a median (50th percentile) of the measured values, the top and bottom of the box represent 25th and 75th percentiles, respectively, and whiskers indicate the range from the largest to smallest observed data points within 1.5 interquartile range presented by the box. Note that ADCs of metastatic nodes are significantly higher than those of nodes with benign lymphadenopathy (P < .01, Mann-Whitney U test).

Graph (box plots) shows ADCs of poorly differentiated and of moderately or highly differentiated squamous cell carcinomas metastasized to cervical lymph nodes. Note that ADCs of metastatic nodes from poorly differentiated cancers are significantly lower than those from moderately or highly differentiated cancers (P < .01, Mann-Whitney U test).

Photomicrographs show metastatic lymph nodes from poorly (A) and highly (B) differentiated squamous cell carcinomas.

A, Poorly differentiated cancer cells with high nuclear-to-cytoplasmic ratios are densely packed in metastatic node.

B, Highly differentiated cancer cells are loosely packed, and amorphous materials (*), probably produced by cancer cells, and fibrous tissues (**) are frequently observed. (Hematoxylin and eosin, original magnification ×200)