“Probably Benign” Grading in Screening Mammograms: Review of Outcomes in a Five-year Study

Full Article

PY Fung, CY Lui, YC Chu, CW Wong, HS Lam

Hong Kong J Radiol 2012;15:64-70

Objective: To evaluate patient outcomes after screening mammograms graded as “probably benign”, and specifically to determine the corresponding frequency of false-negative diagnoses.

Methods:All women with mammograms performed in the Well Women Clinics of Tung Wah Group of Hospitals (Kwong Wah Hospital and Tung Wah Eastern Hospital) from 1 January 2003 to 31 December 2007 were included in this retrospective analysis.

Results:The assessment of “probably benign” was assigned to 4.8% (3182/66,362) of the screening mammograms. Among these 3182 mammograms, 27 were finally diagnosed to have cancer within two years. The percentage of cases designated as “probably benign” but that finally turned out to be malignant was 0.85% (27/3182). The pathological reports for two out of these 27 cases could not be traced. Of the available 25 cases, 17 were at stage 0, six at stage I, and two at stage IIA. None of the lesions were palpable at the time of the diagnosis and they did not have evidence of any systemic metastasis.

Conclusion: At our centre, the assessment of “probably benign” on screening mammograms was on the low side compared to screening programmes elsewhere. In our study population, the percentage of those designated “probably benign” but finally turned out to be malignant was also much lower than the internationally recognised acceptable standards. In our screened population with such a diagnosis, the tumour size, lymph node status, and cancer stages were typical of lesions having a favourable prognosis.


乳房造影檢查中被評為「可能是良性發現」的病例的最終結果: 一個為期五年的研究


目的:評估在乳房造影檢查中被評為「可能是良性發現」的病例的最終結果,並找出假陰性診斷的 發生率。

方法:2003年1月1日至2007年12月31日期間於東華三院轄下的廣華醫院及東華東院的婦女健康普查 部進行乳房造影檢查的女性均被納入本回顧研究中。

結果:乳房造影檢查被評為「可能是良性發現」的佔4.8%(66,362個樣本中的3182個)。3182例 中有27例在兩年內確診為癌症。乳房造影檢查結果為「可能是良性發現」而最終屬惡性的佔0.85% (3182個樣本中的27個)。這27例中有2例未能找到病理學報告。其餘的25例中,17例為零期、6例 為一期、2例為二A期。這些病例中的腫塊都不能在應診期間觸覺得到,亦未有證據顯示屬於系統性 轉移。

結論:與其他地方的篩檢結果比較,在本中心接受乳房造影檢查而評為「可能是良性發現」的結果 較低。與國際認為可接受水平比較,在本中心被評為「可能是良性發現」的結果而最終確診為惡性 腫瘤的比例偏低。本研究中被評為「可能是良性發現」的病例,其腫瘤大小、淋巴結期數及癌症期 都屬於有良好預後的典型病變。