Metaplastic breast carcinoma: sonographic and clinicopathologic comparison with infiltrating ductal carcinoma

Abstract

Abstract Background:There are limited data on the sonographic findings about metaplastic breast carcinoma (MBC) due to its rarity. This article aimed to determine the value of sonographic and clinicopathologic features in improving diagnostic accuracy of MBC and distinguishing it from infiltrating ductal carcinoma(IDC). Methods: In the present study, 197 women (200 lesions) with IDC and 20 women (20 lesions) with MBC were retrospectively reviewed. Sonographic and clinicopathologic characteristics were compared between MBC and IDC. Results: Relative to IDC, most of MBC were tumor grade III(95.0% vs 32.5%, P<0.001), with high Ki67(100.0% vs 75.0%, P<0.001) and triple negative subtype (90.0% vs 13.0%, P<0.001). On ultrasound findings, lesions of MBC tended to have big size (≥5cm,45.0% vs 1.5%, P<0.001), regular shape (45.0% vs 1.5%, P<0.001), circumscribed margin (40.0% vs 0.5%, P<0.001), complex cystic and solid echo(50.0% vs 3.5%, P<0.001) and posterior acoustic enhancement(95.0% vs 14.5%, P<0.001). The most important factors in distinguishing these two tumors were posterior acoustic enhancement, circumscribed margin and size by multilayer perceptron. In MBC cases, the estimated rate of local recurrence, distant metastasis and 5-year overall survival was 10.0%, 30.0% and 65.0%. Conclusions: MBC is mainly manifested as a large breast mass with benign ultrasound findings in elderly women, which may be helpful for diagnosis of MBC and its differential diagnosis from other masses.