Small Subcutaneous Soft Tissue Tumors (<5 cm) Can Be Sarcomas and Contrast-Enhanced Ultrasound (CEUS) Is Useful to Identify Potentially Malignant Masses.

Subcutaneous masses smaller than 5 cm can be malignant, in contrast with the international guidelines. Ultrasound (US) and magnetic resonance imaging (MRI) are useful to distinguish a potentially malignant mass from the numerous benign soft tissue (ST) lesions. Contrast-enhanced ultrasound (CEUS) was applied in ST tumors, without distinguishing the subcutaneous from the deep lesions. We evaluated CEUS and MRI accuracy in comparison to histology in differentiating malignant from nonmalignant superficial ST masses, 50% smaller than 5 cm. Sensitivity, specificity, and positive and negative predictive values (PPV, NPV) with their 95% confidence intervals (CI) were calculated. Of malignant cases, 44.4% measured ≤5 cm. At univariate analysis, no statistically significant differences emerged between benign and malignant tumors in relation with clinical characteristics, except for relationship with the deep fascia (p = 0.048). MRI accuracy: sensitivity 52.8% (CI 37.0, 68.0), specificity 74.1% (CI 55.3, 86.8), PPV 73.1% (CI 53.9, 86.3), and NPV 54.1% (CI 38.4, 69.0). CEUS accuracy: sensitivity 75% (CI 58.9, 86.3), specificity 37% (CI 21.5, 55.8), PPV 61.4% (CI 46.6, 74.3), and NPV 52.6% (CI 31.7, 72.7). CEUS showed a sensitivity higher than MRI, whereas PPV and NPV were comparable. Also, masses measuring less than 5 cm can be malignant and referral criteria for centralization could be revised.

Nipple-Sparing Mastectomy: Reliability of sub-areolar sampling and frozen section in predicting occult nipple involvement in breast cancer patients.

INTRODUCTION: The oncological safety of nipple-areolar complex (NAC) preservation is a concern in the mastectomies performed for cancer indication. The detection of tumor cells during the intraoperative frozen section examination (IE) of sub-areolar/nipple tissue (SAT) leads to the removal of NAC, but frequently the final histology of the nipple is negative for malignancy. This study aims to evaluate the accuracy of SAT examination in predicting occult NAC involvement in case of Nipple-Sparing Mastectomy (NSM). METHODS: The study includes 76 NSM. We evaluated the concordance between histopathologic features of frozen and paraffin-embedded SAT sections. Moreover, we examined the "true margin" (TM), defined as the measurement of the distance between the tumor margin and the edge of the SAT. A margin >1 mm was considered negative. RESULTS: In 26/76 cases the IE of the SAT was positive. At the final histology, the NAC was negative in 57.7% of cases. The concordance between frozen and paraffin section examination of the SAT was 92.1%. The three false-positives were low-grade DCIS at the IE, and negative or DIN1a on permanent section. A negative TM seems to predict for a negative NAC (6/6). CONCLUSIONS: The detection of a low-grade DCIS at the IE of the SAT may not be confirmed at the permanent section examination; we recommend caution in removing the NAC in these cases. The evaluation of the TM may improve the accuracy of SAT analysis in predicting occult NAC involvement; in our series, a TM wider than 1 mm correlates with a negative NAC.