To analyze the quality of ultrasound diagnosis and the causes of misdiagnosis of breast disease during pregnancy and lactation, and to explore the measures to improve the accuracy of ultrasound diagnosis.

From January 2016 to December 2019, 44 patients with gestational and lactational breast disease diagnosed by surgical pathology at Peking Union Medical College Hospital were analyzed, with an average age of (33.41±5.11) years. Ultrasound description, diagnostic accuracy, and examiner seniority were analyzed. Chi-square test was used to compare the ultrasound diagnosis between different seniority groups (ultrasound examiners included 14 residents/attending sonographists and 30 professors; there were 27 breast sonographists and 17 non-breast sonographist).

All 44 cases were described completely. The ultrasound diagnoses of 37 cases (84.1%) were consistent with the pathological results, and inconsistent diagnoses occurred in 7 cases (15.9%). Among the 7 misdiagnosed cases, 2 cases of invasive ductal carcinoma, 1 case of intraductal carcinoma, and 1 case of invasive micropapillary carcinoma were misdiagnosed as benign, and 2 cases of adenosis and 1 case of intraductal papilloma were misdiagnosed as malignant. The diagnostic accuracy by residents/attending sonographists and professors was 78.6% and 86.7%, respectively, and there was no significant difference between the two groups (χ²=0.468, P=0.662). The diagnostic accuracy by breast specialists and non-breast specialists was 92.6% and 70.6%, respectively, and there was also no significant difference between them (χ²=3.776, P=0.089).

Ultrasound diagnosis of breast disease during pregnancy and lactation is difficult. Sonographists should be familiar with the sonographic features, examine the lesions carefully and comprehensively, and make a diagnosis on the basis of clinical manifestations.