Markedly high signal intensity lesions in the uterine cervix on T2-weighted imaging: differentiation between mucin-producing carcinomas and nabothian cysts.

PURPOSE: Both mucin-producing carcinomas and nabothian cysts in the cervix show very high signal intensity on T2-weighted images (WI). The purpose of this study was to evaluate the potential of MR imaging in differentiating mucin-producing carcinomas from nabothian cysts. MATERIALS AND METHODS: Forty-six patients who underwent hysterectomy and had very high signal intensity lesions in the uterine cervix on T2-WI were included in this study. The pathological diagnoses were mucin-producing carcinoma in 13 patients, non-mucin-producing carcinoma accompanied with nabothian cyst in four patients, and nabothian cyst in 29 patients. T1-WI, T2-WI, and Gd-T1-WI were obtained in all patients. Malignancies were diagnosed on Gd-T1-WI as follows: (1) an enhanced lesion, (2) an irregular margin, (3) iso-intensity on T1-WI. In contrast, high signal intensity on T1-WI was considered benign. RESULTS: Thirteen of 17 malignant lesions and three of 29 benign lesions were enhanced. Irregular margins were observed in 12 of 17 malignant lesions and four of 29 benign lesions. Nineteen benign lesions and seven malignant lesions demonstrated high signal intensity on supplemental T1-WI. Combining the lesion criteria of enhancement, irregular lesion margin, and iso-intensity on T1-WI, the overall accuracy, sensitivity, and specificity rates of diagnosing malignancy were 89%, 88%, and 90%, respectively (p < 0.01). CONCLUSION: MR imaging accurately differentiated mucin-producing carcinomas from nabothian cysts that showed high signal intensity on T2-WI in the cervical stroma. For diagnosing mucin-producing carcinomas and nabothian cysts when signal intensity was remarkably high on T2-WI, Gd-T1-WI findings provided key information for differentiation, and T1-WI was useful for improving specificity.