Diagnostic Performance of MR‐guided Vacuum‐Assisted Breast Biopsy: 8 Years of Experience

Breast magnetic resonance imaging (MRI) has demonstrated increased sensitivity over conventional imaging in identifying and characterizing in situ and invasive, multifocal, and multicentric disease. A histologic diagnosis is required for any enhancing lesion displaying suspicious features, especially in the presence of lower and often variable reported specificity values. Breast MRI findings occult on mammography and ultrasound should undergo an MR‐guided biopsy. We retrospectively evaluate our 8 years’ experience with this procedure. Our study included 259 lesions in 255 consecutive patients referred for MR‐guided breast biopsy. MRI screening of women at a high risk for developing breast cancer accounted for 84 lesions, 54 lesions were detected on MRI staging for multifocal and multicentric disease, and 115 were incidental findings or lesions that presented diagnosis related issues on conventional imaging. Six procedures were cancelled due to lack of visualization. MR‐guided breast biopsy was performed for 100 mass and 153 nonmass enhancements. Pathology results were classified into benign (113 lesions), high risk (47 lesions), and malignant (40 ductal carcinoma in situ, 38 invasive ductal carcinoma, 15 invasive lobular carcinoma). Subsequent surgery for high risk and malignant findings revealed an underestimation rate of 34% (16/47) for high risk lesions and of 7.5% for ductal carcinoma in situ (3/40). The overall positive predictive value (PPV) was calculated at 43.1% (33.3% for high‐risk women, 70.3% for cancer staging, and 37.4% for incidental/undetermined lesions). The PPV was higher for mass (57%) versus nonmass enhancements (34%). MR‐guided breast biopsy proved to be a reliable procedure for the diagnosis and management of occult breast MRI findings, or lesions that preclude biopsy under conventional guidance. The PPV displayed significant variation between patient subgroups, correlating higher values with a higher associated breast cancer prevalence.     

Apocrine Metaplasia Found at MR Biopsy: Is There Something to be Learned?

The purpose of this study was to determine (a) the frequency of apocrine metaplasia (ApoM) found on MR core biopsy of suspicious findings, and (b) to determine if there are specific MR imaging features that might obviate the need for biopsy. This HIPAA‐compliant retrospective study was performed under IRB exemption for quality assurance studies. Patient demographics, MR imaging features, and pathology were reviewed. Breast lesions which underwent MR‐guided biopsy, yielding ApoM on pathology analysis were included. Retrospective review of MR imaging features of these lesions was performed by two radiologists blinded to pathology results except for the presence of ApoM. Imaging features on MR assessed included location, size, morphology, T1 and T2 signals, and enhancement kinetics. Full pathology results were subsequently reviewed during data analysis. The pathology slides and imaging was subsequently reviewed by two fellowship trained radiologists and a breast pathologist to categorize the finding of ApoM into target lesion (imaging corresponds to size of lesion on pathology) versus incidental lesion. Target lesion characteristics were assessed to determine specific MRI features of ApoM. Between January 2011 to November 2012, 155 distinct breast lesions suspicious for malignancy successfully underwent MR‐guided biopsy. Of the 155 lesions biopsied, 123 (79%) were benign and 32 (21%) were malignant. Of the 123 benign biopsies, ApoM was found in 57 (46%), of which 35 (61%) had no associated atypia and 22 (39%) had associated atypia. Of the 32 malignant biopsies, three (9%) had associated ApoM (DCIS in two cases and DCIS/LCIS in one case). Of the 60 cases with ApoM, only 11 (18.3%) were target lesions and 49 were incidental lesions (81.7%). Of the 60 cases with ApoM, 35 (58%) were masses (average size 0.8 cm for both with or without atypia) and 25 (42%) were nonmass enhancement (NME) (average size 2.1 cm with and 1.0 cm without atypia). Only five (14%) of 35 masses demonstrated spiculated margins, of which four were associated with atypia (80%). Of 22 lesions with atypia or other high‐risk lesion, 14 (64%) were masses, most commonly with irregular margins (64%). Of the 12 T2 hyperintense lesions, only two (1.7)% had associated atypia or high‐risk lesion, and none were associated with malignancy. Of the 11 target lesions, seven were T2 hyperintense. Enhancement kinetics were variable: 30 (50%) showed mixed persistent and plateau kinetics, eight (13%) persistent delayed enhancement, 10 (17%) plateau kinetics, four (7%) washout kinetics, and eight (13%) were below threshold for kinetic analysis. ApoM is a common benign pathologic result at MR‐guided core biopsy for both masses and NME accounting for 39% of all biopsy results in this series. Although there is considerable variability in imaging characteristics on MR, our results suggest biopsy may be safely obviated for lesions that are subcentimeter T2 hyperintense areas of NME and short term follow‐up imaging may be a reasonable alternative for these lesions.     

The Management of Benign Concordant MRI‐guided Breast Biopsies: Lessons Learned

After benign concordant magnetic resonance imaging (MRI)‐guided breast biopsy, initial follow‐up MRI at 6 months is often recommended for confirmation. This study was undertaken to determine the proper management of stable lesions on initial follow‐up MRI and whether such follow‐up can be safely deferred to 12 months. Retrospective review of 240 MRI‐guided biopsies identified 156 benign concordant lesions. 85 eligible cases received follow‐up MRI and constitute the study population. On initial follow‐up MRI, 72 of 85 lesions appeared adequately sampled, 12 were stable and underwent further MRI follow‐up, and 1 was benign on subsequent surgery. No cancers were diagnosed at the biopsy sites on either 6‐ or 12‐month follow‐up MRI. Among the 12 stable lesions, four were masses and eight were nonmass enhancements. One of the stable masses enlarged on 24‐month follow‐up MRI and proved malignant. All stable nonmass lesions were benign on long‐term follow‐up. After benign concordant MRI‐guided breast biopsy, a stable mass has a 25% probability of malignancy in our series. Re‐biopsy of such masses should be strongly considered. Stable nonmass lesions may be followed with subsequent MRI without rebiopsy. Deferral of initial follow‐up MRI to 12 months may be acceptable.     

MR imaging appearance of noncalcified and calcified DCIS

To evaluate the MR appearance of noncalcified ductal carcinoma in situ (DCIS), with comparison to calcified DCIS. A retrospective, IRB‐approved review of all DCIS diagnosed via MR biopsy between 2007 and 2011 was performed. DCIS was categorized as noncalcified based on the absence of calcifications on mammography and specimen radiography. MR morphology (focus, mass, nonmass enhancement [NME]) and enhancement kinetics (initial and delayed) for noncalcified DCIS were recorded and compared based on nuclear grade (1‐3), size (<1.5 cm, 1.5‐5 cm, >5 cm), and presence of necrosis. Imaging features of noncalcified and calcified DCIS were also compared. 115 cases of MR biopsy‐proven DCIS were identified: 65 (56%) noncalcified and 50 (44%) calcified. For noncalcified DCIS, NME morphology was more common than mass or focus (60% vs 30.8% and 9.2%). There was a significant association between morphology and enhancement kinetics, with NME more likely demonstrating medium and persistent kinetics, and foci or masses demonstrating rapid and plateau or washout kinetics (P < .05). There was also a significant association between morphology and nuclear grade, with NME more likely seen with grade 3 DCIS (P = .024), and between size and initial enhancement, with lesions <1.5 cm more likely to have rapid initial enhancement (P = .0036). No significant difference was identified between calcified and noncalcified DCIS in terms of morphology, enhancement characteristics, nuclear grade, or presence of necrosis. The MR appearance of noncalcified DCIS closely mirrors that of calcified DCIS. Recognizing these imaging features may allow for improved identification of this MRI‐detected abnormality, even in the absence of calcifications.     

Usefulness of MRI prior to prostate needle biopsy in PSA gray zone

To evaluate the diagnostic accuracy of prostate magnetic resonance imaging (MRI), we compared MRI findings with the results of biopsy as well as findings from specimens following total prostatectomy. The subjects consisted of 260 males who showed a prostate specific antigen (PSA) level in the gray zone (4 ng/ml ≤PSA <10 ng/ml) and also underwent digital rectal examination (DRE), transrectal ultrasound (TRUS), and MRI prior to prostate biopsy between April 2005 and December 2009. In Evaluation 1, the results of DRE/TRUS/MRI were compared with those of prostate biopsy. The biopsy-positive rate was higher in males positive in each examination. However, 24.8% of males negative in all examinations were biopsypositive. Thus, these examinations were considered to be inappropriate for secondary screening. In evaluation 2, the prostate was divided into 4 regions, and the findings from specimens following total prostatectomy were compared with MRI findings in each region. For the region containing prostate cancer, MRI showed a sensitivity of 26.0%, specificity of 98.3%, positive predictive value of 96.2%, and negative predictive value of 44. 4%. In patients with a Gleason score ≥7, cancer foci were more frequently detectable using MRI. MRI prior to prostate biopsy in patients in the PSA gray zone is inappropriate for secondary screening due to its low sensitivity. However, by virtue of its high positive predictive value, MRI is useful for determining patients indicated for biopsy, as well as DRE and TRUS. Accurate evaluation of the localization of all cancer lesions is difficult using MRI. However, when MRI findings are present, they frequently indicate the cancer lesion, which may be useful information for treatment.     

Pathologic correlates of false positive breast magnetic resonance imaging findings: which lesions warrant biopsy?

BACKGROUND: Contrast-enhanced breast magnetic resonance imaging (MRI) is highly sensitive for breast cancer. However, adoption of breast MRI is hampered by frequent false positive (FP) findings. Though ultimately proven benign, these suspicious findings require biopsy due to abnormal morphology and/or kinetic enhancement curves that simulate malignancy on MRI. We hypothesized that analysis of a series of FP MRI findings could reveal a pattern of association between certain "suspicious" lesions and benign disease that might help avoid unnecessary biopsy of such lesions in the future. METHODS: A retrospective chart review identified women undergoing breast MRI between June 1995 and March 2002 with FP findings identified by MRI alone. Lesions were retrospectively characterized according to an MRI Breast Imaging-Reporting and Data System lexicon and matched to pathology. RESULTS: Twenty-two women were identified with 29 FP lesions. Morphology revealed 1 focus (3.5%), 5 masses less than 5 mm (17%), 11 masses greater than 5 mm (38%), 1 (3.5%) linear enhancement, and 11 (38%) non-mass-like enhancement. Kinetic curves were suspicious in 15 (52%). Histology demonstrated 20 (69%) variants of normal tissue and 9 (31%) benign masses. MRI lesions less than 5 mm (n = 6, 20.5%) were small, well-delineated nodules of benign breast tissue. CONCLUSION: Suspicious MRI lesions less than 5 mm often represent benign breast tissue and could potentially undergo surveillance instead of biopsy.     

Pseudoangiomatous stromal hyperplasia. A case for bilateral mastectomy in a 12-year-old girl

Pseudoangiomatous stromal hyperplasia (PASH) is a benign proliferation of breast stromal cells with a complex pattern of interanastomosing spaces lined by myofibroblasts and is most commonly seen in women of child-bearing age. PASH is a frequent incidental microscopic finding in breast biopsies. Nodular PASH, however, resulting in a clinically appreciable mass and rapid growth is a rare entity, with only four such patients cited in the literature. Surgical excision results in a cure in the majority of cases, with a recurrence rate of approximately 7-22%. We report a case of a 12-year-old girl with nodular PASH who presented with bilateral breast enlargement refractory to surgical excisions, eventually requiring bilateral mastectomies. To our knowledge, our patient is the youngest patient to have nodular PASH and to undergo bilateral mastectomies.     

Mammary pseudoangiomatous stromal hyperplasia presenting as an axillary mass

Pseudoangiomatous stromal hyperplasia (PASH) of the breast is characterized by interanastomosing slit-like spaces lined with spindle-shaped cells in an abundant fibrous stroma. PASH is a relatively common incidental finding in the breast tissue removed for other reasons and rarely presents as a localized mass. The etiology of PASH is unknown, but hormonal factors are thought to be involved. Accessory breast tissue is subject to all pathologic changes found in the normal breast. We report a case of PASH that presented as a palpable axillary mass in a 43-year-old woman. To our knowledge, PASH has not previously been reported in the axillary accessory breast tissue. The spindle stromal cells in our patient showed immunophenotypic characteristics of myofibroblastic differentiation. Immunoreactivity for progesterone receptor was noted in the spindle cells. These findings support the hypothesis that endogenous hormones are involved in the development of PASH.     

Incidence and outcomes of incidental breast lesions detected on cross‐sectional imaging examinations

The aim of this study was to determine the frequency and outcomes of incidental breast lesions detected on nonbreast specific cross‐sectional imaging examinations. A retrospective review of the medical records was performed to identify all patients without a known history of breast cancer, who had an incidentally discovered breast lesion detected on a nonbreast imaging examination performed at our institution between September 2008 and August 2012 for this IRB‐approved, HIPAA compliant study. Outcomes of the incidental lesions were determined by follow‐up with dedicated breast imaging (mammography, breast ultrasound, and/or breast MRI) or results of biopsy, if performed. Imaging modality of detection, imaging features, patient age, patient location at the time of the nonbreast imaging examination, type of follow‐up, and final outcome were recorded. Rates of malignancy were also calculated, and comparison was made across the different cross‐sectional imaging modalities. Kruskal‐Wallis and Fisher's exact tests were used to identify factors associated with an increased rate of malignancy. Logistic regression was used to model the risk of malignancy as a function of continuous predictors (such as patient age or lesion size); odds ratios and 95% confidence intervals were obtained. A total of 292 patients with incidental breast lesions were identified, 242 of whom had incidental lesions were noted on computed tomography (CT) studies, 25 on magnetic resonance imaging (MRI), and 25 on positron emission tomography (PET). Although most of the incidental breast lesions were detected on CT examinations, PET studies had the highest rate of detection of incidental breast lesions per number of studies performed (rate of incidental breast lesion detection on PET studies was 0.29%, compared to 0.10% for CT and 0.01% for MRI). Of the 121 of 292 (41%) patients who received dedicated breast imaging work‐up at our institution, 40 of 121 (33%) underwent biopsy and 25 of 121 (21%) had malignancy. There was a significantly increased rate of malignancy in older patients (odds ratio: 1.05, 95% CI: 1.02‐1.093; P = .006). Additionally, patients with PET‐detected incidental breast lesions had a significantly higher rate of malignancy (55%), compared to patients with CT‐detected (35%) and MRI‐detected (8%) incidental breast lesions (P = .038). The rate of malignancy upon follow‐up of incidental breast lesions detected on nonbreast imaging examinations in this retrospective study was 21%, supporting the importance of emphasizing further work‐up of all incidentally detected breast lesions with dedicated breast imaging. Additionally, we found that PET examinations had the highest rate of detection of incidental breast lesions and the highest rate of malignancy, which suggests that PET examinations may be more specific for predicting the likelihood of malignancy of incidental breast lesions, compared to CT and MRI.     

Incidence and morphologic characteristics of benign calcaneal cystic lesions on MRI

BACKGROUND: Since we have frequently noted osseous cyst-like lesions within the calcaneus on MRI studies, we sought to systematically evaluate this finding to determine the incidence and morphologic characteristics on MRI. METHODS: Three observers blinded to age evaluated 198 MRIs of the ankle (74 males, 124 females; mean age 47 years, range 13 to 99 years), recording the presence and size of calcaneal cyst-like foci. Statistical analysis was performed to determine if there was an association with age. Additionally, MRI of 12 ankles precontrast and postcontrast were reviewed for the presence of blood vessels in the calcaneus corresponding to the location of the cyst-like lesions and 24 ankle MR arthrograms were reviewed to evaluate communication of the cyst with the adjacent joint. RESULTS: Of the 198 ankle MRI examinations, 81 (40%) had hyperintense foci, all within the mid-calcaneal body. The size ranged from 0.01 cm(2) to 2.47 cm(2), with a mean size of 0.36 cm(2) (+/- 0.45 cm(2)). Thirty-seven (46%) were linear or elongated, whereas 44 (54%) were ovoid or round. Seven of the 81 foci (8.6% or 3.5% of the total population) were 1 cm(2) or larger. There was no significant association of patient age and presence (p = 0.49) or size (p = 0.48) of the focus. Location of the cyst-like foci, which often are ovoid or linear, corresponds to penetrating microvessels on precontrast and postcontrast MRI. One MR arthrogram showed communication of a cyst-like focus and the subtalar joint. CONCLUSIONS: Calcaneal lesions are relatively common incidental findings on MRI. These lesions appear to represent intraosseous ganglion cysts that arise from the anterior margin of the posterior facet of the subtalar joint in the anatomical neighborhood where vessels penetrate the superior calcaneal cortex. The lesions can vary is size; however, there is no correlation between patient age and lesion size and no significant association between age and presence of these foci.     

Pitfalls with MRI evaluation of prostate cancer detection: comparison of findings with histopathological assessment of retropubic radical prostatectomy specimens

INTRODUCTION: To assess differences between MRI findings and histopathologically defined prostate cancer localization, we compared clinical results with mapping of radical prostatectomy specimens, and conducted a retrospective MRI cancer localization re-assessment by a urologist-technician after surgery. METHODS: We performed MRI for a total of 37 suspected prostate cancer patients. Subsequently, all underwent retropubic radical prostatectomy after prostate biopsy for confirmation of the diagnosis. All the specimens were studied histopathologically with serial sectioning using a whole organ approach. RESULTS: Of the 37 patients, 26 had positive MRI findings. All the surgical specimens contained cancerous lesions, and 23 had multiple foci. Twenty-four of the MRI-positive cases (92.3%) demonstrated coincidence of both MRI and histopathologically defined lesions. In the single focus cases, 78.6% (11/14) demonstrated exact coincidence, but in the multifocal cases there were no cases with exact coincidence of MRI and histopathological findings (0/23). CONCLUSION: MRI evaluation cannot be considered an effective diagnostic tool in itself for detection of prostate cancers because sensitivity is far from satisfactory, especially in multi-focal cases.     

MR Imaging Findings in Molecular Subtypes of Breast Cancer According to BIRADS System

To evaluate magnetic resonance imaging (MRI) findings, according to Breast Imaging‐Reporting and Data System (BI‐RADS), and to relate them with molecular subtypes of breast cancer. The MRI findings were reviewed retrospectively in 201 women diagnosed of invasive breast cancer confirmed by surgery and were compared with the molecular subtypes. Following the BI‐RADS, MRI findings included disease type, size, enhancement, morphology and contrast kinetics. In mass‐like lesion types were studied shape, margin and enhancement, and in nonmass‐like lesion types, distribution modifiers and internal enhancement. Chi‐squared analysis showed significant association (p < 0.01) between molecular subtypes and lesion type on MRI and histologic grade. Shape, margin and mass enhancement (p < 0.05) also showed significant association among molecular subtypes. Triple negative were more frequently unifocal and mass‐like lesion, high histologic grade, round shape, smooth margin, and rim enhancement. Luminal‐A were more frequently low grade, mass‐like lesion, irregular shape and spiculated or irregular margin. Luminal‐B were more frequently moderate‐low grade, mass‐like lesion, nonirregular shape and spiculated margin. HER‐2‐enriched were more frequently moderate grade, nonmass‐like lesion and multicentric lesions were more present than in other subtypes. There are significantly different MRI features, according to BI‐RADS, between the molecular subtypes breast cancer.     

Breast Nonmass Enhancement Detected with MRI: Uility and Lesion Characterization with Second‐Look Ultrasonography

The purpose of this study was to verify the utility of second‐look ultrasonography (US) in evaluating nonmass enhancement (NME) lesions detected on breast magnetic resonance imaging (MRI) by analysing its correlation and imaging features. From July 2008 to June 2012, 102 consecutive MRI‐detected NME lesions were subsequently evaluated with US. Lesions were evaluated according to the established Breast Imaging Reporting and Data System (BI‐RADS) lexicon. The correlation between MRI‐detected NME lesion characteristics, lesion size, histopathological findings and features at second‐look US were analysed. Second‐look US identified 44/102 (43%) of the NME lesions revealed by MRI. A US correlate was seen in 34/45 (76%) malignant lesions compared with 10/57 (18%) benign lesions (p < 0.0001). The likelihood of malignancy was significantly higher for NME lesions with a US correlate than lesions without: 34/44 (77%) versus 11/58 (19%) (p < 0.0001). The malignancy of the 44 (43%) MRI‐detected NME lesions with a US correlate was significantly associated with US lesion margins and BI‐RADS categories (p = 0.001 and 0.002 respectively). Second‐look US of MRI‐detected NME lesions is useful for decision‐making as part of the diagnostic workup. Familiarity with the US features associated with malignancy improves the utility of US in the workup of these NME abnormalities.     

Atypical small acinar proliferation: biopsy artefact or distinct pathological entity?

OBJECTIVE: To determine if atypical small acinar proliferation (ASAP) represents minimally sampled prostate cancer not fully evaluated on a biopsy or a distinct pathological entity, by examining prostates removed at radical cystectomy, as a finding of ASAP of the prostate on needle-core biopsy is closely associated with the detection of cancer on subsequent biopsy. PATIENTS AND METHODS: In all, 65 consecutive cystoprostatectomy specimens taken from June 1990 to March 2004 had prostatic material reviewed by one genitourinary pathologist (S.E.M.). The presence of high-grade prostatic intraepithelial neoplasia (HGPIN), ASAP, and adenocarcinoma was recorded. Foci of ASAP found in the absence of cancer were assessed with additional sectioning, high-molecular weight keratin (CK903), and alpha-methylacyl coenzyme A racemase (AMACR) immunohistochemistry. RESULTS: In all, 24 of 65 specimens (37%) had adenocarcinoma. Of the 41 without cancer, 18 (44%) had neither HGPIN nor ASAP, 14 (34%) had HGPIN alone, three (7%) had ASAP alone (four foci), and six had both HGPIN and ASAP (15%). Two foci of ASAP were not present on any further sectioning. The remaining eight foci all lacked CK903 stain, indicating disruption of the basal cell layer. Of these eight, only five were present for the AMACR stain, all of which were positive. Two of these five developed into a lesion considered cancer on further sectioning. CONCLUSION: ASAP identified in incidental prostates represented marginally sampled cancer in at least two of 10 foci assessed. The remainder could not be resolved as benign on further evaluation, and remained suspicious for malignancy.     

Magnetic resonance imaging patterns of tumor regression in breast cancer patients after neo‐adjuvant chemotherapy,and an analysis of the influencing factors

The objective of this study was to analyze the patterns of breast tumor shrinkage in patients after neo‐adjuvant chemotherapy (NAC) based on magnetic resonance imaging (MRI), and to evaluate the influential factors. Preoperative breast dynamic contrast‐enhanced MRI was performed on 88 patients before NAC, every 2 weeks during their chemotherapy treatment, and the week before their surgery. The MRI enhancement pattern of the primary tumors was classified into one of four categories based on BI‐RADS‐MRI: type I (postcontrast mass image), II (multiple small masses image), III (postcontrast mass image with peripheral non‐mass enhancement image), and IV (nonmass enhancement image). Multivariate regression and χ² test analyses were employed to establish significant associations. Two kinds of tumor regression patterns were observed: concentric shrinkage was observed in 39 lesions of 88 patients (44.3%), and nests or dendritic shrinkage was observed for the other 49 lesions (55.7%). ER+/HER2?, HER2+, and type I lesions were observed in 23 (62.2%), 21 (63.6%), and 29 (60.0%) patients, respectively, out of 49 nest or dendritic shrinkage pattern lesions. Triple negative breast cancer lesions, and type II, III, and IV lesions were observed in 13 (72.2%), 9 (81.8%), 10 (62.5%), and 10 (76.9%) patients, respectively, out of 39 lesions with a concentric shrinkage pattern. Molecular subtypes (χ²=7.171, P<.05) and the MRI schedule of enhancement (χ²=11.244, P<.05) were significantly associated with the tumor regression patterns. Multivariate analysis showed molecular subtypes (P<.05) and MRI pattern enhancement (P<.05) were significant predictive factors. Molecular subtypes and the MRI enhancement patterns of the primary tumors were significant predictive factors for tumor regression patterns of breast cancer after NAC.     

Pregnancy-like (pseudolactational) hyperplasia: a primary diagnosis in mammographically detected lesions of the breast and its relationship to cystic hypersecretory hyperplasia

Pregnancy-like (pseudolactational) hyperplasia (PLH) has long been recognized as an incidental finding in breast biopsies performed for various clinically detected benign and malignant conditions. The histologic features of PLH have been well described, including some instances exhibiting cytologic and structural atypia. The presence of calcifications in these lesions was rarely mentioned and was considered to be of little consequence. More recently, however, calcifications in PLH have become the target of needle localization and needle core biopsies. The authors report 12 instances in which PLH was the primary diagnosis in biopsy specimens obtained for radiographic abnormalities, usually calcifications. Six of 12 procedures (50.0%) were performed for mammographically detected calcifications, four cases for a mass, one for an "abnormal mammogram," and one for galactorrhea. Calcifications were present in PLH in 10 biopsies, in benign terminal ducts in one specimen, and were not identified histologically in the remaining specimen. In most instances, calcifications associated with PLH had smooth round or lobulated contours and distinctive, internal, unevenly spaced laminations. Cystic hypersecretory hyperplasia (CHH) was present in five specimens. In four of the five specimens, CHH merged with PLH (PLH/CHH). Four of 12 specimens (33.3%) showed atypia within foci of PLH/CHH. PLH should be recognized as a primary diagnosis in breast biopsies for mammographically detected abnormalities such as calcifications. Some calcifications associated with PLH have a distinctive histologic appearance, and their recognition can aid in the diagnosis of PLH. Additional cases of PLH/CHH must be studied to ascertain the clinical significance, if any, of this previously undescribed entity. The precancerous significance of PLH/CHH and of PLH with atypia has not been determined. In most instances, surgical excision would be prudent if PLH/ CHH or PLH with atypia is present in a needle core biopsy specimen.     

MAGNETIC RESONANCE IMAGING OF CLINICALLY LOCALIZED PROSTATIC CANCER

Purpose

We assess the accuracy of endorectal coil magnetic resonance imaging (MRI) for detecting tumor localization, capsular penetration and seminal vesicle invasion in clinically organ confined prostate cancer. We also evaluate intra-observer and interobserver agreement in interpreting MRI studies.

Materials and Methods

MRI studies of 51 consecutive patients a mean of 61 years old with biopsy proved prostate cancer were retrospectively read twice by 2 radiologists in random order. Both radiologists marked tumor localization, capsular penetration and seminal vesicle invasion on standard tumor maps. These findings were compared with the histopathological results of radical prostatectomy specimens.

Results

The overall accuracy of detecting cancer localization was 61%. The detection rate for cancer foci less than 5 mm. was only 5% but for lesions greater than 10 mm. it was 89%. There was 91 and 80% accuracy for detecting capsular penetration and seminal vesicle invasion, respectively. Sensitivity and specificity were 60 and 63, 13 and 97, and 59 and 84% for localization, capsular penetration and seminal vesicle invasion, respectively. Intra-observer and interobserver agreement ranged from fair to good (kappa coefficient 0.240 to 0.647).

Conclusions

Endorectal MRI seems to be better than previously reported for detecting seminal vesicle invasion and tumor foci in the anterior half of the prostate. Sensitivity in detecting minor capsular penetration of the tumor was low, which can probably be improved by methodological development. MRI may be useful for locating cancer foci in patients with high prostate specific antigen values but repeatedly negative biopsy findings.     

Use of serial multiparametric magnetic resonance imaging in the management of patients with prostate cancer on active surveillance

IntroductionWe evaluated the performance of multiparametric prostate magnetic resonance imaging (mp-MRI) and MRI/transrectal ultrasound (TRUS) fusion–guided biopsy (FB) for monitoring patients with prostate cancer on active surveillance (AS).Materials and methodsPatients undergoing mp-MRI and FB of target lesions identified on mp-MRI between August 2007 and August 2014 were reviewed. Patients meeting AS criteria (Clinical stage T1c, Gleason grade≤6, prostate-specific antigen density≤0.15, tumor involving≤2 cores, and≤50% involvement of any single core) based on extended sextant 12-core TRUS biopsy (systematic biopsy [SB]) were included. They were followed with subsequent 12-core biopsy as well as mp-MRI and MRI/TRUS fusion biopsy at follow-up visits until Gleason score progression (Gleason≥7 in either 12-core or MRI/TRUS fusion biopsy). We evaluated whether progression seen on mp-MRI (defined as an increase in suspicion level, largest lesion diameter, or number of lesions) was predictive of Gleason score progression.ResultsOf 152 patients meeting AS criteria on initial SB (mean age of 61.4 years and mean prostate-specific antigen level of 5.26 ng/ml), 34 (22.4%) had Gleason score≥7 on confirmatory SB/FB. Of the 118 remaining patients, 58 chose AS and had at least 1 subsequent mp-MRI with SB/FB (median follow-up = 16.1 months). Gleason progression was subsequently documented in 17 (29%) of these men, in all cases to Gleason 3+4. The positive predictive value and negative predictive value of mp-MRI for Gleason progression was 53% (95% CI: 28%–77%) and 80% (95% CI: 65%–91%), respectively. The sensitivity and specificity of mp-MRI for increase in Gleason were also 53% and 80%, respectively. The number needed to biopsy to detect 1 Gleason progression was 8.74 for SB vs. 2.9 for FB.ConclusionsStable findings on mp-MRI are associated with Gleason score stability. mp-MRI appears promising as a useful aid for reducing the number of biopsies in the management of patients on AS. A prospective evaluation of mp-MRI as a screen to reduce biopsies in the follow-up of men on AS appears warranted.     

Features of Occult Invasion in Biopsy‐Proven DCIS at Breast MRI

The purpose of this study is to determine if MRI BI‐RADS criteria or radiologist perception correlate with presence of invasive cancer after initial core biopsy of ductal carcinoma in situ (DCIS). Retrospective search spanning 2000–2007 identified all core‐biopsy diagnoses of pure DCIS that coincided with preoperative MRI. Two radiologists fellowship‐trained in breast imaging categorized lesions according to ACR MRI BI‐RADS lexicon and estimated likelihood of occult invasion. Semiquantitative signal enhancement ratio (SER) kinetic analysis was also performed. Results were compared with histopathology. 51 consecutive patients with primary core biopsy‐proven DCIS and concurrent MRI were identified. Of these, 13 patients (25%) had invasion at excision. Invasion correlated significantly with presence of a mass for both readers (p = 0.012 and 0.001), rapid initial enhancement for Reader 1 (p = 0.001), and washout kinetics for Reader 2 (p = 0.012). Significant correlation between washout and invasion was confirmed by SER (p = 0.006) when threshold percent enhancement was sufficiently high (130%), corresponding to rapidly enhancing portions of the lesion. Radiologist perception of occult invasion was strongly correlated with true presence of invasion. These results provide evidence that certain BI‐RADS MRI criteria, as well as radiologist perception, correlate with occult invasion after an initial core biopsy of DCIS.