Departments of Pathology.
Radiology.
Am J Surg Pathol. 2020 Feb;44(2):182-190. doi: 10.1097/PAS.0000000000001385.
Flat epithelial atypia (FEA) is an alteration of terminal duct lobular units by a proliferation of ductal epithelium with low-grade atypia. No consensus exists on whether the diagnosis of FEA in core needle biopsy (CNB) requires excision (EXC). We retrospectively identified all in-house CNBs obtained between January 2012 and July 2018 with FEA. We reviewed all CNB slides and assessed radiologic-pathologic concordance. An upgrade was defined as invasive carcinoma (IC) and/or ductal carcinoma in situ in the EXC. The EXC slides of all upgraded cases were rereviewed. Out of ∼15,700 consecutive CNBs in the study period, 106 CNBs from 106 patients yielded FEA alone or with classic lobular neoplasia (LN). We excluded 52 CNBs (40 patients with prior/concurrent carcinoma and 12 without EXC). After rereview, we reclassified 14 cases (2 marked nuclear atypia, 10 focal atypical ductal hyperplasia, 2 benign). The final FEA study cohort consisted of 40 CNBs from 40 women. The CNB targeted mammographic calcifications in 36 (90%) cases, magnetic resonance imaging nonmass enhancement in 3 (8%), and 1 (2%) sonographic mass. All CNBs were deemed radiologic-pathologic concordant. FEA was present alone in 34 CNBs and with LN in 6. EXC yielded 2 low-grade IC, each spanning <2 mm, identified in tissue sections without biopsy site changes. The remaining 38 cases had no upgrade. Classic LN did not affect the upgrade. The upgrade rate of FEA was 5%; both minute, low-grade "incidental" IC. We conclude that nonsurgical management may be considered in patients without prior/concurrent carcinoma and radiologic-pathologic concordant CNB diagnosis of FEA.
平坦上皮不典型（FEA）是终末导管小叶单位的一种改变，表现为低级别不典型的导管上皮增生。在核心针活检（CNB）中，FEA 的诊断是否需要切除（EXC）尚未达成共识。我们回顾性地确定了 2012 年 1 月至 2018 年 7 月期间所有在本院进行的 FEA 核心针活检。我们复习了所有 CNB 切片，并评估了影像学-病理学的一致性。升级定义为 EXC 中的浸润性癌（IC）和/或导管原位癌。所有升级病例的 EXC 切片均重新评估。在研究期间，大约 15700 例连续 CNB 中，106 例 CNB 来自 106 例患者，单独或伴有经典小叶肿瘤（LN）出现 FEA。我们排除了 52 例 CNB（40 例有先前/同时存在的癌，12 例无 EXC）。重新评估后，我们重新分类了 14 例（2 例核异型明显，10 例局灶性不典型导管增生，2 例良性）。最终的 FEA 研究队列由 40 例来自 40 名女性的 CNB 组成。36 例（90%）CNB 针对乳腺 X 线照相术钙化，3 例（8%）针对磁共振成像非肿块强化，1 例（2%）针对超声肿块。所有 CNB 均被认为与影像学-病理学一致。34 例 CNB 单独存在 FEA，6 例存在 LN。EXC 发现 2 例低级别 IC，每个病例的大小均＜2mm，在没有活检部位改变的组织切片中发现。其余 38 例无升级。经典 LN 不影响升级。FEA 的升级率为 5%；均为微小的、低级别“偶然”IC。我们得出结论，对于无先前/同时存在的癌且 CNB 诊断为 FEA 且影像学-病理学一致的患者，可以考虑非手术治疗。
