Incidental Breast Masses on Ultrasound: What are Their Characteristics and Clinical Outcome?
VYK To, CY Lee, CX Chan, SL Fung
Hong Kong J Radiol 2015;18:146-50
DOI: 10.12809/hkjr1514292
Objective: To evaluate the characteristics and clinical outcome of non-palpable breast lesions screened by ultrasound.
Methods: From January 2011 to June 2011, all new cases referred to the breast clinic at Tuen Mun Hospital, Hong Kong, were identified. All patients underwent ultrasound with or without mammography. Patients with a palpable or mammographically detected breast mass were included in the control group. Patients with non-palpable breast lesions detected incidentally on ultrasound only were included in the investigation group. Any patients who underwent targeted ultrasound were excluded. Baseline patient demographics, including age and family history of breast cancer, were documented. Lesion characteristics on ultrasound, including maximum dimension and Breast Imaging Reporting and Data System (BI-RADS) classification, were analysed. The nature of the lesions was confirmed histologically or by follow-up imaging for at least 2 years to indicate benignity.
Results: A total of 196 patients with 422 lesions were identified. Among the 422 lesions, 130 were palpable or mammographically detected lesions (control group) and 292 were non-palpable ultrasound-detected lesions (investigation group). The baseline characteristics in both groups were comparable. The mean age was 44 years in the control group and 42 years in the investigation group. There were 10 and 8 patients with a family history of breast cancer in the control group and investigation group, respectively. Compared with the control group, the maximum dimension of the lesion was significantly smaller in the investigation group (p < 0.05). The BI-RADS classification was significantly lower in the investigation group (p < 0.05). A total of 156 lesions had tissue diagnosis and 270 lesions were followed up for at least 2 years with no change or a decrease in size, indicating benignity. In the control group, 18 (13.8%) lesions were malignant while in the investigation group, no lesions were malignant (p < 0.05).
Conclusion: Ultrasound can detect small lesions that are mammographically occult and non-palpable. However, these lesions are likely more benign-looking (BI-RADS 2/3) and pathologically benign.
中文摘要
超聲偶然發現的乳腺腫塊的特徵和臨床結局
杜婉筠、李芷茵、陳積聖、馮小玲
目的：評估臨床觸診未捫及但於超聲檢查發現的乳腺病變的特徵和臨床結局。
方法：收集於2011年1月至6月期間被轉介至香港屯門醫院乳腺專科的新症病例。所有病人均已進行超聲檢查，部分也接受了乳腺X線攝影。觸診或乳腺X線攝影發現腫塊的病例均被列入對照組。觸診未及但於超聲偶然發現乳腺腫塊的病例則被納入研究組。研究排除所有接受針對性超聲檢查的病例。記錄研究初始階段病人的人口學統計資料，包括其年齡和乳腺癌家族史，並分析超聲檢查中的乳腺腫塊特徵，包括腫塊最大直徑、乳腺影像報告和數據系統（BI-RADS）分級。病變性質由組織學檢查確診；或依據兩年以上的隨訪影像檢查來提示病變為良性。
結果：總計196名病人，含422例乳腺腫塊被納入研究。422例乳腺腫塊中，130例為可觸及或乳腺X線攝影發現（對照組），另292例為未觸及但於超聲檢查中發現（研究組）。研究組和對照組的基線特徵相若。對照組與研究組平均年齡分別為44歲和42歲，另分別有10人和8人有乳腺癌家族史。研究組腫塊最大直徑顯著小於對照組（p < 0.05），其BI-RADS分級亦較低（p < 0.05）。共有156個腫塊有組織學診斷，270個腫塊隨訪兩年以上無變化或體積變小，提示為良性。對照組中，18個腫塊（13.8%）為惡性；研究組中則沒有發現任何惡性病變（p < 0.05）。
結論：超聲可探測到乳腺X線攝影中隱匿性和觸診未及的小腫塊；但多數腫塊為良性外觀形態（即BI-RADS分級2和分級3），其病理學診斷也為良性。