Non-contrast-enhanced CT findings of high attenuation within metastatic cervical lymph nodes in patients with stage I or II tongue carcinoma during a follow-up period

Abstract

We present the non-contrast-enhanced CT finding of high attenuation within metastatic regional lymph nodes in two patients with stage I or II tongue carcinoma during a follow-up period. The attenuation values of these lesions were approximately 70 HU or more. One patient had a level I node, and the other had a level II node. Contrast-enhanced CT failed to reveal these hyperattenuated areas within the nodes. Histopathologic examination revealed that these hyperattenuated areas were strongly correlated with the area of marked keratinization of metastatic foci. If contrast-enhanced CT had been the only imaging technique used, these lesions might have been overlooked. The clinician should be aware of the characteristic findings of non-contrast-enhanced, as well as contrast-enhanced, CT when investigating lymph node metastases at an early stage in patients with stage I or II tongue carcinoma during the follow-up period.

Fig 1

Case 1, a 79-year-old woman with squamous cell carcinoma of the left side of her tongue. A, Non-contrast-enhanced CT image obtained at initial examination of a level I node (arrow); no hyperattenuation is evident. B, First follow-up sonogram at the level I node obtained 1 month after surgery of the primary tumor (transverse section). Note an enlarged lymph node (arrow) with heterogeneous internal echo. MB indicates mandible. C, Non-contrast-enhanced CT image at the level I node obtained 1 month after surgery of the primary tumor. Hyperattenuation entirely occupies the node (arrow). The size of the node has increased, and the minimal axial diameter of the node is 10 mm. D, Contrast-enhanced CT image obtained at the same level and time as that of A. Hyperattenuation within the node (arrow) is obscured after the administration of contrast medium. E, Photomicrograph (stain, hematoxyllin-eosin; original magnification, ×2.5) shows the level I node is entirely replaced by the area of marked keratinization (arrows). The non-contrast-enhanced CT finding of hyperattenuation is likely correlated with this marked keratinization.

Fig 2

Case 2, an 80-year-old woman with squamous cell carcinoma of the right side of her tongue. A, Non-contrast-enhanced CT image at a level II node (arrow) obtained at initial examination; hyperattenuation is not evident. B, Ninth follow-up sonogram at the level II node obtained 7 months after surgery of the primary tumor (transverse section). Note an enlarged lymph node (arrow) with heterogeneous internal echo. C, Non-contrast-enhanced CT image at the level II node obtained 7 months after surgery of the primary tumor. Note the hyperattenuation (arrowhead) at a lateral margin of the node (arrow). The size of the node increases and the minimal axial diameter of the node is 9 mm. D, Contrast-enhanced CT image obtained at the same level and time as that of C. The level II node (arrow) enhances, and hyperattenuation is obscured after the administration of contrast medium. E, Photomicrograph (stain, hematoxyllin-eosin; original magnification, ×2) demonstrates the area of marked keratinization (arrows) within metastatic foci at the marginal portion of the largest one of level II node. The non-contrast-ehnahced CT finding of hyperattenuation appears to be correlated with this marked keratinization within metastatic foci.