Value of contrast-enhanced MRI in the differentiation between nasopharyngeal lymphoid hyperplasia and T1 stage nasopharyngeal carcinoma.

OBJECTIVES

To investigate the value of contrast-enhanced MRI in differentiation between benign nasopharyngeal lymphoid hyperplasia (NPLH) and T1 stage nasopharyngeal carcinoma (NPC).

METHODS

Eighty-six NPLH patients and 38 T1 stage NPC patients who underwent a contrast-enhanced MRI and an endoscopic biopsy were included. The patients' symptoms and MRI features of nasopharyngeal mucosal thickening like location, symmetry, nasopharyngeal bubble, superficial mucus, nasopharyngeal retention cysts, serrated protrusions, contrast-enhancement type were documented. Accompanying signs such as sinus mucosal thickening, middle ear effusion, and cervical lymph nodes enlargement were also recorded. These MRI features were compared by Chi-square tests. Logistic regression analysis was done to identify the most predictive MRI features of malignancy.

RESULTS

NPLH patients had more symptoms of pharynx discomfort or pain, while T1 stage NPC patients had more symptom of neck mass (P < 0.05). The most common pattern of nasopharyngeal mucosal thickening in NPLH was diffuse wall thickening (38.37%), while unilateral posterolateral wall thickening (39.47%) was more in T1 stage NPC. Nasopharyngeal bubble, retention cysts, serrated protrusions, symmetry, homogeneous enhancement, slight enhancement and vertical stripes were more common in NPLH, while nasopharyngeal wall asymmetry, inhomogeneous enhancement, moderated or marked enhancement and cervical lymph nodes enlargement were more in T1 stage NPC (P < 0.05). Logistic regression analysis identified unilateral posterolateral wall thickening, nasopharyngeal wall asymmetry, inhomogeneous enhancement and cervical lymph nodes enlargement were the most predictive MRI features for malignancy.

CONCLUSIONS

Careful analysis of contrast-enhanced MRI features of the nasopharynx and neck is helpful in differentiating benign NPLH from T1 stage NPC.