Focal extravasated mucin in breast core needle biopsies: is surgical excision always necessary?

Focal extravasated mucin (EM) with benign or atypical epithelium is a rare finding at breast core needle biopsy (CNB) and usually prompts surgical excision to rule out mucin-producing carcinoma. In the largest detailed series to date, we assessed surgical outcomes in lesions yielding EM with atypical or nonatypical epithelium at CNB. With IRB approval, we retrospectively reviewed 28 consecutive atypical and nonatypical CNBs with EM that underwent surgical excision at our center over a 22-year period. CNB imaging and pathologic findings were concordant if pathology sufficiently explained the radiologic features of the lesions. Pathologic findings in CNB and excision specimens were correlated. Statistical analysis was performed. CNBs sampled mammographic calcifications in 25/28 (89%) women and a mass in 3/28 (11%). All cases had concordant pathologic and imaging findings. At CNB, the epithelium associated with EM was atypical in 18/28 (64%) lesions and nonatypical in 10 (36%). Cancer (one mucinous carcinoma; three ductal carcinoma in situ) was present in 4/28 excision specimens (14%; 95% confidence intervals [CI], 4%-33%). All carcinomas were in lesions with epithelial atypia at CNB (4/18; 22%; 95% CI, 6%-48%) versus none (0/10; 0%; 95% CI, 0%-31%) in nonatypical lesions at CNB; this difference was not statistically significant (p = 0.3). Surgery is warranted for lesions yielding EM with atypia at CNB due to the high (22%) prevalence of cancer. Our data suggest that surgical excision of lesions yielding EM without epithelial atypia at CNB may not be necessary provided that imaging and pathologic findings are concordant.

Classic lobular carcinoma in situ and atypical lobular hyperplasia at percutaneous breast core biopsy: outcomes of prospective excision.

BACKGROUND: No consensus exists on the need to excise breast lesions that yield classic lobular carcinoma in situ (LCIS) or atypical lobular hyperplasia (ALH) (known together as classic lobular neoplasia [LN]) as the highest risk lesion at percutaneous core-needle biopsy (CNB). Here, the authors report findings from 72 consecutive lesions with LN at CNB and prospective surgical excision (EXB). METHODS: Lesions that yielded LN at CNB at the authors' center have been referred for EXB since June 2004, regardless of imaging-histologic concordance. A lesion was "concordant" if histologic findings provided sufficient explanation for imaging. An upgrade consisted of ductal carcinoma in situ and/or invasive carcinoma at EXB. Statistical analysis, including 95% confidence intervals (CIs), was performed. RESULTS: Between June 2004 and May 2009, CNB of 85 consecutive lesions yielded LN without other high-risk histologies. Eighty of 85 lesions (94%) underwent prospective EXB. Seventy-two of 85 lesions (90%; 42 LCIS, 30 ALH) had concordant imaging-histologic findings. EXB yielded low-grade carcinoma in 2 of 72 cases (3%; 95% CI, 0%-9%). In both patients, stereotactic, 11-gauge, vacuum-assisted biopsy of calcifications yielded calcifications in benign parenchyma and ALH. CNB results were discordant in 8 of 80 lesions (10%; 4 LCIS, 4 ALH), and EXB yielded cancer in 3 of those 8 lesions (38%; 95% CI, 9%-76%). The upgrade rate was significantly higher for discordant lesions versus concordant lesions (38% vs 3%; P < .01). CONCLUSIONS: Prospective excision of LN identified carcinoma in 3% (95% CI, 0%-9%) of concordant cases versus 38% (95% CI, 9%-76%) of discordant cases. The current data provide an unbiased assessment of the upgrade rate of LN diagnosed at CNB.

Intracystic papillary carcinoma of the breast: An in situ or invasive tumor? Results of immunohistochemical analysis and clinical follow-up.

Intracystic papillary carcinoma (IPC) is regarded as an intraductal neoplasm, but recent evidence suggests that it could be invasive, as it often lacks myoepithelial lining. We evaluated myoepithelial cells and collagen IV, a basement membrane component, in 40 IPCs from 39 (35 female and 4 male) patients and assessed their clinical management and follow-up. The mean patient age at diagnosis was 68 years, and the mean tumor size was 1.8 cm. Thirteen cases were pure IPC, 8 cases were IPC with or without microinvasion, and 19 cases were IPC with invasive carcinoma (IPC+IC), including 1 mucinous and 1 cribriform carcinoma. Ductal carcinoma in situ associated more often with IPC+IC (84.2%) than with pure IPC (61.5%) or IPC with or without microinvasion (62.5%). Myoepithelial cells were completely absent in 33 of 40 (82.5%) IPCs, and only focal in the remaining 7 of 40 cases (17.5%). Collagen IV lining was discontinuous in most cases (89%). All tumors were estrogen receptor positive and HER2 negative; most were progesterone receptor positive (93%). Eleven patients underwent mastectomy and 28 lumpectomy; 3 of 27 (11%) patients had lymph node involvement. Fourteen of all patients treated with breast conservation received radiation, 10 hormonal treatment, and none chemotherapy. Four patients treated conservatively (3 with pure IPC and 1 with IPC+IC) recurred locally, including one who later developed bone metastasis. We conclude that IPC constitutes a spectrum of intraductal and IC, with predominance of the latter. IPC rarely involves lymph nodes and carries very good prognosis, but can recur locally. This type of tumor is strongly estrogen receptor positive and hormonal therapy should be pursued for its management, whereas the benefit of radiation after lumpectomy remains unclear.

Endosalpingiosis in axillary lymph nodes: a possible pitfall in the staging of patients with breast carcinoma.

The occurrence of benign epithelial inclusions in lymph nodes is well documented and can sometimes mimic metastatic carcinoma. Benign müllerian inclusions, such as endometriosis and endosalpingiosis, are common in pelvic and para-aortic lymph nodes, but their presence in supradiaphragmatic lymph nodes is a rare event. We report our experience with 3 patients found to have endosalpingiosis in axillary sentinel lymph nodes obtained for staging of breast carcinoma. All patients were postmenopausal women, with age ranging between 65 and 75 years. Endosalpingiosis involved a single lymph node in 1 patient, and 2 nodes in each of the other 2; it was present in the lymph node capsule in all the 3 cases, with few glands scattered within the lymph node parenchyma in 2 of the patients. The glands contained ciliated and intercalated peg cells, had no periglandular endometrial-type stroma, and showed no atypia or mitotic activity. The epithelium demonstrated positive nuclear immunoreactivity for WT1 and PAX8, and was devoid of myoepithelium or basement membrane. Endosalpingiosis had been misinterpreted as metastatic carcinoma at another hospital in 1 of the 3 patients, with subsequent dissection of 19 additional benign axillary lymph nodes. We conclude that endosalpingiosis can involve axillary lymph nodes and closely simulate metastatic mammary carcinoma. Morphologic identification of ciliated cells and "peg" cells is most helpful to recognize this benign inclusion, and positive immunoreactivity for WT1 and/or PAX8 can be used to support the diagnosis.

Concurrent lobular neoplasia increases the risk of ipsilateral breast cancer recurrence in patients with ductal carcinoma in situ treated with breast-conserving therapy.

BACKGROUND: Multiple clinicopathologic factors have been analyzed for their association with an increased risk of ipsilateral breast tumor recurrence (IBTR) after women receive breast-conserving treatment (BCT) for ductal carcinoma in situ (DCIS). The reported incidence of proliferative lesions, such as atypical ductal hyperplasia (ADH), columnar cell changes (CCC), and lobular neoplasia associated with breast cancer, has been as high as 23%; however, the relevance of these lesions on the natural history of DCIS and the risk of IBTR remains unknown. METHODS: Two hundred ninety-four patients with DCIS who received BCT between 1991 and 1995 were identified from the authors' institutional database. Slides were reviewed by a dedicated breast pathologist with particular attention to the presence of lobular neoplasia, ADH, and CCC. The actuarial 5-, 10-, and 15-year IBTR rates were calculated using the Kaplan-Meier method and were compared using the log-rank test. RESULTS: Concurrent lobular neoplasia was present in 41 of 294 patients (14%), ADH was present in 37 of 294 patients (13%), and CCC was present in 71 of 294 patients (24%). The median follow-up was 11 years. IBTR occurred in 40 of 227 patients without lobular neoplasia (18%) versus 15 of 41 patients with lobular neoplasia (37%; P=.005; hazard ratio [HR], 2.49). The 5-, 10-, and 15-year cumulative incidence rates of IBTR were twice as high in women who had DCIS and lobular neoplasia compared with women who had DCIS alone (P=.002). Concomitant ADH (HR, 1.53) and CCC (HR, 1.24) were not associated significantly with IBTR (P=.20 and P=.44, respectively). CONCLUSIONS: Concurrent lobular neoplasia is associated with a significantly higher risk of IBTR in women with DCIS who received BCT. Women with coexisting DCIS and lobular neoplasia who receive BCT should consider using additional risk-reducing strategies.