Intranodal cystic changes: a potential radiologic signature/biomarker to assess the human papillomavirus status of cases with oropharyngeal malignancies.

OBJECTIVE: The aim of this study was to determine if lymph node imaging findings can predict human papillomavirus (HPV) positivity in oropharyngeal squamous cell cancers. METHODS AND MATERIALS: Pretreatment postcontrast neck computed tomographic scans of 49 patients (male, 35; female, 14; age range, 45-76 years) diagnosed with oropharyngeal malignancies and with available HPV data were retrospectively reviewed. Metastatic lymph nodes were identified based on standardly accepted size and morphological criteria. Various lymph node parameters were studied, including presence of cystic foci in the metastatic lymph nodes, abnormal lymph nodes showing low-attenuation foci, matted lymph nodes, and morphologically normal smaller (<1.5 cm) lymph nodes. These parameters were then independently correlated with the available HPV status of these patients. Finally, an extended criterion, that is, intranodal cystic changes in cases with morphologically normal small (<1.5 cm) lymph nodes, was correlated with HPV status. Sensitivity, specificity, and positive predictive values (PPVs) and negative predictive values (NPVs) were calculated.
RESULTS: Of these 49 cases with oropharyngeal cancers, 27 were HPV positive, and 22 cases were HPV negative. Eight cases (3 HPV positive and 5 HPV negative) did not have metastatic lymph nodes. Of remaining 41 cases with metastatic abnormal lymph nodes, 26 were HPV positive, and 15 were HPV negative. Of these 41 cases with metastatic lymph nodes, 14 had 1 or more lymph nodes with cystic foci. Of these 14 cases, 10 (71.4%) were HPV positive. Resultant sensitivity, specificity, PPV, and NPV of cystic foci for the presence of HPV status were 38.4%, 73.3%, 71.4%, and 40.7%, respectively. Intranodal cystic changes in cases with morphologically normal small (<1.5 cm) lymph nodes were found in 5 cases; all 5 were HPV positive. Resultant accuracy was specificity and PPV of 100%, sensitivity of 19.2% and NPV of 41.6%.
CONCLUSIONS: Intranodal cystic changes seen on the pretreatment postcontrast neck computed tomographic scan of patients with oropharyngeal malignancies are radiologic signatures strongly associated with the HPV status of the patient. The results in this initial study warrant larger prospective studies to determine if this finding may be used in addition to other molecular biomarkers to help identify those patients who may be amenable to the most appropriate treatment options.