Preoperative MRI Evaluation of Axillary Lymph Nodes in Invasive Ductal Carcinoma: Comparison of Luminal A Versus Luminal B Subtypes in a Paradigm Using Ki-67 and Receptor Status.

OBJECTIVE: The purpose of this study is to assess whether luminal A versus luminal B molecular subtypes of breast cancer affect the diagnostic utility of preoperative MRI evaluation of the axilla. MATERIALS AND METHODS: This study identified 125 patients who underwent preoperative breast MRI evaluation of tumors classifiable as luminal A or luminal B molecular subtypes between January 2012 and August 2014. The subtypes were classified on the basis of immunohistochemical staining surrogates combining receptor status and the Ki-67 proliferation index. Statistical analysis was performed using chi-square analysis and one-way ANOVA. When a statistically significant difference was found, follow-up analysis involving pairwise comparison using the Bonferroni correction was performed. Multivariate logistic regression analysis was also used to determine whether the molecular subtype was independently predictive of lymph node involvement. RESULTS: A total of 80 patients had tumors classifiable as the luminal A molecular subtype, whereas 45 patients had tumors classifiable as the luminal B subtype. Pathologically proven axillary lymph node (ALN) disease occurred statistically significantly more frequently in luminal B tumors (18/45 [40.0%]) than in luminal A tumors (11/80 [13.8%]; p < 0.01). In addition, pathologically proven ALN disease was 4.3 times more likely to occur in luminal B tumors after controlling for patient age, tumor size, and tumor grade (p < 0.01). We found no difference in the negative predictive value of the MRI assessment of the axilla when luminal A tumors were compared with luminal B tumors. The positive predictive value of MRI evaluation of ALNs is statistically significantly higher for luminal B tumors than for luminal A tumors (76.2% vs 28.0%, respectively; p = 0.004). CONCLUSION: With the use of molecular subtype classification including the Ki-67 proliferation index, suspicious nodes detected in luminal B tumors by MRI are likely to have positive findings and warrant preoperative tissue sampling. Conversely, in view of the high false-positive rate of suspicious nodes detected in luminal A tumors by MRI, proceeding straight to sentinel lymph node biopsy for all cases, except for those with highly suspicious findings, is suggested. These results should, however, be validated in a larger prospective study.

Phyllodes tumor: review of key imaging characteristics.

Phyllodes tumor of the breast is rare and often resembles the more commonly seen fibroadenoma at imaging and histologically. As core biopsy cannot always distinguish the two, assessing radiologic-pathologic concordance is essential to guide appropriate clinical management. We review the imaging characteristics of phyllodes tumor at mammography, ultrasound, and MRI to help the interpreting radiologist be aware of key imaging features that should alert him to the possibility of a phyllodes tumor even if not verified by initial core biopsy.

Should the extent of lobular neoplasia on core biopsy influence the decision for excision?

The purpose of this study was to determine whether there is a criterion that can be utilized to determine if excisional biopsy is indicated following the diagnosis of lobular neoplasia (LN) on core biopsy. Retrospective review of patient records with diagnosis of LN as highest risk diagnosis on core biopsy was performed. LN was defined to include both atypical lobular hyperplasia (ALH) and lobular carcinoma in situ (LCIS) and was categorized as focal or diffuse. The pathology was correlated with the mammographic finding to determine whether the diagnosis of LN was incidental or related to the mammographic finding. For those patients who did not undergo excision, follow-up data are presented along with treatment information. A total of 4,555 breast core biopsies were performed at our institution from January 1997 through March 2005. Of these, 35 patients were diagnosed with LN. Twenty six (74%) went on to excision and nine (26%) were followed. Biopsy was recommended for mammographically detected calcifications in the majority of cases. Twenty four (92%) of the 26 excised cases had focal LN and 2 of 26 (8%) had diffuse LN. Infiltrating lobular carcinoma was diagnosed in both cases of diffuse LN and no infiltrating carcinoma was seen when focal LN was diagnosed on core. Excision may not be necessary when a diagnosis of only focal LN is made on core biopsy. Diffuse LN may indicate an associated invasive cancer and should prompt excision.

Common and unusual diseases of the nipple-areolar complex.

The nipple-areolar complex is often best evaluated as a separate region of the breast. Because of the intricacy of the anatomic structures and their superficial position, the diagnostic techniques required for optimal evaluation of the nipple-areolar complex differ from those routinely used to evaluate the whole breast. Although clinical examination and screening mammography are still of central importance, the adjunct use of multiple imaging modalities (ultrasonography, contrast material-enhanced magnetic resonance imaging, or both) as well as nonstandard mammographic views is often necessary to differentiate benign abnormalities from malignant ones. For accurate diagnosis, familiarity with a wide range of appearances of the normal anatomy, including congenital anomalies (eg, supernumerary nipples), is necessary, as is a thorough knowledge of the features of the benign and malignant processes that commonly occur in the nipple-areolar complex. Benign abnormalities may include mammary duct ectasia, nipple calcifications, cutaneous horn of the nipple, abscess of the Montgomery gland, and nipple adenoma. Malignant abnormalities may include Paget disease and primary lymphoma as well as carcinoma of the breast. Some conditions, such as nipple retraction and inversion, may have either a benign or a malignant cause. In such cases, a thorough radiologic assessment is especially important.

Imaging findings after breast brachytherapy.

OBJECTIVE: The purpose of this study was to determine whether there are imaging changes specific to partial breast radiation therapy with interstitial catheters or a single balloon. MATERIALS AND METHODS: The records of 43 of 83 patients treated with partial breast irradiation at our institution from June 1996 to October 2003 were retrospectively reviewed. The images of 27 patients who had received radiation by interstitial catheters and 16 who had received radiation by a single balloon were reviewed. Patients were examined for the presence of skin thickening, diffuse and focal increased density, mass, lucency, and calcifications. Fifteen initial sonograms were ordered to evaluate pain or focal findings on mammograms. In addition, two patients underwent one and one patient underwent three follow-up sonographic examinations. RESULTS: Mild to moderate skin thickening was present in 26 (60%) and no skin thickening in 17 (40%) of the 43 patients. Forty-one (95%) of the 43 patients had focal increased density. Diffuse increased density was seen in only one (2%) of the patients. There was no change in overall density in 2 (5%) of the patients. Fifteen (35%) of the 43 patients had mass or seroma at the first follow-up examination. Central lucency was present in 35 (81%) of 43 patients on at least one follow-up study. Calcification was present in 8 (19%) of 43 cases. CONCLUSION: Imaging findings after breast brachytherapy include the spectrum of findings seen with external beam radiation but are more focal. The focal findings may be alarming both clinically and radiographically, but biopsy can be avoided in most instances if information from the history is correlated with findings from continued follow-up of the patient's case.

Recognizing pitfalls in early and late migration of clip markers after imaging-guided directional vacuum-assisted biopsy.

Directional vacuum-assisted biopsy has become an irreplaceable tool in the management of suspicious mammographic lesions. Often, the entire lesion is removed and clips are used to localize the biopsy site. Postbiopsy mammograms are used to determine the adequacy of clip placement and the location of the clip. Clip displacement from the site of deployment is not an uncommon finding. Clips may migrate within the same quadrant where the lesion was located or to another quadrant of the breast. Clip migration may occur immediately after biopsy or may be seen on later follow-up mammograms. Clip migration can affect interpretation of mammographic findings and localization for future surgery. It should not be assumed that the clip is correctly located at the biopsy site on subsequent mammograms. It is essential to recognize the relationship of the clip to the targeted lesion to ensure accurate localization of lesions that require surgical excision.

Large-needle core biopsy in atypical intraductal epithelial hyperplasia including immunohistochemical expression of high molecular weight cytokeratin: analysis of results of a single institution.

The diagnosis of atypical intraductal epithelial hyperplasia (AIDH) constitutes 6.3% of the breast core biopsies performed at our institution. Seventy-nine cases that were diagnosed as AIDH on core biopsy and went through excisional biopsy were included. Sixty-four biopsies were performed by an image-guided 11-gauge vacuum device, 11 under sonographic guidance using 14-gauge needles and 4 by a sonographically guided 11-gauge vacuum device. The histopathology of the core biopsies and the surgical excisions were reviewed. Immunohistochemistry was performed on the consecutive sections of core biopsy specimens using high molecular weight cytokeratin (HMW-CK) (DAKO-Cytokeratin, 34betaE12). At interpretation of the stain, intensity and percentage of positive cells were taken into account. The immunoprofiles of AIDH were categorized into four groups showing negative (i.e., no staining) or low-, moderate-, high-, and very high-intensity staining. Surgical excision of the 79 lesions revealed carcinoma in only 3 cases (4%)-two infiltrating carcinomas and one intraductal carcinoma-residual AIDH in 44 cases (56%), and epithelial hyperplasia or other benign lesions without atypia in 32 cases (40%). The HMW-CK stain was performed retrospectively on all of the core biopsies and 66 of them contained residual areas with AIDH for staining. Forty-nine (74%) were CK negative or stained with low intensity, but 17 cases (26%) had a moderate- to high-intensity stain. Our study showed a lower incidence of carcinoma on surgical excision following core biopsy for AIDH than other studies. The HMW-CK stain helped to characterize the nature of the intraductal proliferation and to confirm the presence of atypia, as has been previously reported, but frequently was inconclusive. The low incidence of carcinoma brings into question the need for surgical excision of all cases of AIDH diagnosed by core biopsy.

Osseous metaplasia of the breast: diagnosis with stereotactic core biopsy.

There are approximately 200 reported cases of breast tumors containing areas of bone. The majority of the neoplasms are sarcomas, phylloides tumors, or fibroadenomata. We present a case of osseous metaplasia mammographically detected by clustered heterogeneous calcifications. Stereotactic core biopsy revealed the presence of well-formed bone tissue without associated neolplasia. The case represents the first reported case of mammographically detected osseous metaplasia confirmed by core biopsy.