No abstract

BackgroundWhen invasive components are discovered at mastectomy for vacuum-assisted biopsy (VAB)-diagnosed ductal carcinoma in situ (DCIS), the only option available is axillary lymph node dissection (ALND). The primary aim of this prospective multicenter trial was to determine the benefit of performing upfront sentinel lymph node (SLN) biopsy for these patients. The secondary aim was to determine DCIS factors associated with microinvasion or invasion.MethodsThe SLN procedure was performed during mastectomy, and for positive SLN an ALND was performed during the same intervention. A tissue microarray containing DCIS lesions from the mastectomy specimens was subsequently performed.ResultsFrom May 2008 to December 2010, 228 patients were enrolled from 14 French cancer centers, including 192 eligible patients with pure DCIS on VAB and successful SLN procedures. ALND was avoided for 51 [67 %; 95 % confidence interval (CI), 56–77 %] of all the patients who had microinvasive DCIS or DCIS associated with invasive carcinoma at mastectomy and a negative SLN. Of the 192 patients, 76 (39 %) with VAB-diagnosed DCIS were upgraded after mastectomy to micro (n = 20) or invasive disease (n = 56). The rate of positive SLN for patients with DCIS on VAB was 14 %. High nuclear grade of DCIS was associated with greater risk of microinvasion and invasion, and HER2-amplified DCIS was associated with greater risk of invasion.ConclusionsUnderestimation of invasive components is high when DCIS is diagnosed by VAB in patients undergoing mastectomy. Upfront SLN for patients with VAB-diagnosed extensive DCIS avoids unnecessary ALND for two-thirds of patients with micro or invasive disease on mastectomy.Electronic supplementary materialThe online version of this article (doi:10.1245/s10434-015-4476-5) contains supplementary material, which is available to authorized users.

Axillary lymph node dissection in patients with ductal carcinoma in situ (DCIS) of the breast is not warranted because DCIS has no metastatic potential. However, the risk of microinvasive carcinoma (MIC) exists in large DCIS treated by mastectomy. The aim of this series is to evaluate the incidence of lymph node metastases in DCIS and DCIS-MIC. We analyzed retrospectively patients treated in six French cancer centers for pure DCIS or DCIS-MIC. Surgical procedures were lumpectomy or mastectomy associated with an axillary sentinel node (SN) procedure. We included 161 patients suffering from pure DCIS (116/161, 72%) or DCIS-MIC (45/161, 28%). Mean age was 56 years (32-78). We observed underestimation between core biopsy and histological result in 43/142 cases (30%). These data show an association between lesion size, solid subtype, high-grade DCIS, and underestimation. Forty-eight breast conservative procedures were performed and 113 mastectomies (70%). SN procedure was performed using blue dye, technetium, or both. In our series, we selected patients with a high risk of occult invasive carcinoma: high grade (55%), mean size (27 mm), and mastectomy (112). Six SN were found positive (3.7%). In the five patients treated with complete axillary dissection, the SN was the only positive node. SN in DCIS is an interesting procedure but not necessary for all patients. We need to focus on the subgroup with or a high risk of occult MIC: extensive calcifications or palpable mass, DCIS diagnosed by core biopsy and underestimation, multifocality, high grade, large tumor size, MIC, and mastectomy.

Figure 4. Magnetic resonance image. Cystic lymphangioma of the left breast (hypersignal T2).

Hamartomas are uncommon benign breast neoplasms. We report the first case, to our knowledge, of invasive lobular carcinoma arising in a breast hamartoma. This case illustrates the importance of careful interpretation of the clinical and mammographic findings. A more aggressive approach toward the management of breast hamartomas is not justified when clinical and mammographic findings are consistent with classic hamartomas.