To explore the breast ultrasound examination and histopathological findings of breast solid papillary carcinoma (SPC).

A total of 81 patients with breast SPC who underwent surgical treatment at Shanxi Provincial Cancer Hospital from January 2014 to May 2022 and were confirmed by pathological examination of surgically resected tissues were selected as the research subjects. According to pathological subtypes, they were divided into in situ group (n=34) and invasive group (n=47). Retrospective analysis methods were used to collect lesion location, onset age, initial symptoms, breast ultrasound results, and pathological results of the two groups. Statistical analysis was performed using chi-square test, continuity correction chi-square test, or Fisher′s exact probability method. This study followed the requirements of the 2013 revised World Medical Association Declaration of Helsinki.

① Patients with breast SPC were significantly older, with 56 cases (69.1%) aged ≥60 years. The first symptom of 61 cases (75.3%) was a palpable breast mass.There were no statistically significant differences in lesion location, onset age, and initial symptom composition between two groups (P>0.05). ② The results of breast ultrasound examination of these 81 patients showed SPC masses predominantly exhibited a single occurrence (65 cases, 80.2%), hypoechoic characteristics (72 cases, 88.9%), irregular morphology (50 cases, 61.7%), well-defined borders (48 cases, 59.3%), parallel growth orientation (68 cases, 84%), absence of calcification (75 cases, 92.6%), unchanged posterior echo (67 cases, 82.7%), Adler blood flow grade Ⅱ-Ⅲ (49 cases, 60.5%), no lymph node metastasis (80 cases, 98.8%), and no ductal ectasia (61 cases, 75.3%). However, no statistically significant differences were observed between in situ and invasive groups regarding these parameters (all P>0.05). In the invasive group, 89.4% (42/47) of those diagnosed with Breast Imaging Reporting and Data System (BI-RADS) category 4 by breast ultrasound were significantly higher than 67.6% (23/34) in the in situ group (χ²=5.87, P=0.015). ③The immunohistochemical results of surgically resected tissues from 81 patients showed that the estrogen receptor (ER) and progesterone receptor (PR) positive rates of SPC cells were 100.0% (81/81), the P63 positive rate was 39.5% (32/81), and the Syn and CgA positive rates were 63.0% (51/81) and 51.8% (42/81), respectively. The in situ group exhibited significantly higher P63 positive rate than the invasive group, with a statistically significant difference (P<0.001). However, no statistically significant differences were observed between the two groups in Syn and CgA positive rates (P>0.05).

The breast ultrasound examination results of patients with breast SPC have certain characteristics and are closely correlated with the SPC subtypes detected by histopathological examination. The expression of P63 in breast SPC cells is helpful for clinical differentiation of patients with in situ and invasive breast SPC.