Dynamic Contrast-Enhanced Magnetic Resonance Imaging of Regional Nodal Metastasis in Nasopharyngeal Carcinoma: Correlation with Nodal Staging

Objective. To determine if the perfusion parameters by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) of regional nodal metastasis are helpful in characterizing nodal status and to understand the relationship with those of primary tumor of nasopharyngeal carcinoma (NPC). Materials and Methods. Newly diagnosed patients imaged between August 2010 and January 2014 and who were found to have enlarged retropharyngeal/cervical lymph nodes suggestive of nodal disease were recruited. DCE-MRI was performed. Three quantitative parameters, Ktrans, ve, and kep, were calculated for the largest node in each patient. Kruskal-Wallis test was used to evaluate the difference in the parameters of the selected nodes of different N stages. Spearman’s correlation was used to evaluate the relationship between the DCE-MRI parameters in nodes and in primary tumors. Results. Twenty-six patients (7 females; 25~67 years old) were enrolled. Ktrans was significantly different among the patients of N stages (N1, n=3; N2, n=17; N3, n=6), P=0.015. Median values (range) for N1, N2, and N3 were 0.24 min−1 (0.17~0.26 min−1), 0.29 min−1 (0.17~0.46 min−1), and 0.46 min−1 (0.29~0.70 min−1), respectively. There was no significant correlation between the parameters in nodes and primary tumors. Conclusion. DCE-MRI may play a distinct role in characterizing the metastatic cervical lymph nodes of NPC.

Aggressive Metastasizing Pleomorphic Adenoma— A Wolf in Sheep's Clothing: A Case Report with Review of Literature

ABSTRACT Metastasizing pleomorphic adenoma (MPA) is a rarity, and detailed immunohistochemistry (IHC) work-up is being documented in this case. Most cases present with metastasis after a period of several years, ranging from 1.5 to 51 years. The present case deals with a morphologically and immunologically benign pleomorphic adenoma of the parotid, behaving in a paradoxically aggressive fashion at the local site, at the time of initial diagnosis. Regional nodal metastasis and significant local perineural and intraneural infiltration were identified at presentation. In view of the strong tumor neural affinity, the differential diagnosis included an atypical tubular form of adenoid cystic carcinoma (ACC). However, ACC was ruled out on morphology and by IHC. Literature is reviewed and the varied spectrum of reported cases is briefly put forth.