Melcior Sentís

Automatic microcalcification and cluster detection for digital and digitised mammograms

In this paper we present a knowledge-based approach for the automatic detection of microcalcifications and clusters in mammographic images. Our proposal is based on using local features extracted from a bank of filters to obtain a local description of the microcalcifications morphology. The developed approach performs an initial training step in order to automatically learn and select the most salient features, which are subsequently used in a boosted classifier to perform the detection of individual microcalcifications. Subsequently, the microcalcification detection method is extended in order to detect clusters. The validity of our approach is extensively demonstrated using two digitised databases and one full-field digital database. The experimental evaluation is performed in terms of ROC analysis for the microcalcification detection and FROC analysis for the cluster detection, resulting in better than 80% sensitivity at 1 false positive cluster per image.

PRIMARY LYMPHOMA OF THE BREAST: MR IMAGING FEATURES. A CASE REPORT

Primary non-Hodgkins lymphoma (NHL) of the breast are rare and represent less than 0.6% of all mammary malignancies. Secondary involvement of the breast in patients with diffuse disease occurs more frequently. The radiologic features of breast lymphoma are nonspecific, and the diagnosis is based on histologic criteria. We present the MR-imaging features of a case of primary NHL of the breast.

Ductal Carcinoma In Situ and Atypical Ductal Hyperplasia of the Breast Diagnosed at Stereotactic Core Biopsy

Abstract: Stereotactic core needle biopsy (SCNB) allows specific histopathologic diagnoses to be made without surgery and has been demonstrated to be an accurate, cost‐effective method of diagnosing breast disease, particularly nonpalpable lesions. However, recent studies have concluded that the diagnosis of atypical ductal hyperplasia (ADH) by means of SCNB has resulted in nearly equal odds that a coexisting malignant lesion will be missed. Furthermore, others have concluded that SCNB diagnosed as DCIS cannot reliably indicate the absence of tumor invasion in surgical excision. Between 1993 and 1998, 1,221 consecutive SCNB of mammographically identified lesions were performed using a 14‐gauge automated device with an average of 5.3 cores obtained per lesion. ADH was identified in 19 (1.6%) lesions and DCIS in 89 (7.3%). Surgical biopsy was performed in 89 of these patients and histopathologic results from SCNB and surgical biopsies were reviewed and correlated. In 12 cases of ADH diagnosed by SCNB, surgical biopsy showed ADH in 8 (67%) cases and DCIS in the other 4 (33%) cases. In 77 cases of DCIS diagnosed by SCNB, a surgical biopsy showed DCIS in 55 (71%) cases, 6 more cases (8%) had DCIS with focal microinvasion, and 15 (19%) had invasive ductal carcinoma. In one case no residual tumor was found at surgery. In the authors patient population, the diagnosis of ADH at SCNB indicates high probability of DCIS or residual ADH in the surgical biopsy. The diagnosis of DCIS at SCNB is confirmed in the majority of surgical biopsies; however, a significant number of cases may show microinvasion or invasive carcinoma.

Enhancement of intramammary lymph nodes with lymphoid hyperplasia: a potential pitfall in breast MRI

Abstract. We present three cases of breast lesions labeled as probable intramammary lymph nodes that showed an increase in size on follow-up mammography. Contrast-enhanced MRI was performed and the three lesions showed strong and rapid uptake of the intravenous contrast. Core needle biopsy established the diagnosis of lymphoid hyperplasia in all three patients. Because intramammary lymph nodes affected by benign processes can present findings similar to malignant lesions, the usefulness of contrast-enhanced MRI in these cases is controversial.

The Great Mimicker: Fat Necrosis of the Breast—Magnetic Resonance Mammography Approach

Fat necrosis of the breast is a common benign inflammatory process resulting from injury to breast fat. The pathogenesis of fat necrosis helps to explain its imaging features, which range from benign to malignant-appearing findings. This article reviews the role of magnetic resonance mammography and other conventional imaging techniques in the differential diagnosis of fat necrosis.

Interval breast cancers in a community screening programme: frequency, radiological classification and prognostic factors.

The frequency of interval cancers (IC) can be an indicator inversely related to the quality of a breast screening programme. The objectives were to estimate the frequency of IC, to classify IC by posterior radiological review, and to describe the prognostic factors of these IC. The setting was the Sabadell-Cerdanyola Breast Cancer Screening Programme, in Northeast Spain. We developed a population-based study of the IC occurring in the first three rounds (1995–2001). The indicators used were the incidence rate of invasive IC per 10 000 women screened and the proportional incidence, stratified by age group, type of screening and the round, and the time elapsed since the last screening mammogram. A radiological informed consensus review was used to classify the IC. No specific pattern of incidence rates was evident with respect to age, type of screening, or round, although screening was generally more sensitive in women aged 60–69 years. The proportional incidence for the period 0–11 months was always under 30%. Twenty-one percent of 38 IC evaluated (95% CI: 8.0–34.0) were attributed to errors in the screening process (false negatives). No major differences in the prognostic factors of the 57 IC were identified on examining the radiological type or the time since the last screening mammogram. We observed a high frequency of IC from 12 months after screening. It is necessary to reach a consensus regarding the definition and the analysis of IC and to establish mechanisms that would allow all the malignant tumours diagnosed in the target population to be identified.

The impact of stereotactic large-core needle biopsy in the treatment of patients with nonpalpable breast lesions: a study of diagnostic accuracy in 510 consecutive cases

Abstract. The objective of this study was to assess the usefulness of stereotactic large-core needle biopsy (LCNB) in the management of nonpalpable breast lesions (NBL) and compare it with stereotactic fine-needle aspiration biopsy (SFNA) performed simultaneously in a significant number of cases. From November 1993 through June 1997, 510 consecutive patients with NBL underwent 14-gauge LCNB with 354 women undergoing simultaneous 21-gauge SFNA in the same lesion. Mammographic findings, lesion size, number of core biopsy specimens, complications and diagnoses of both techniques were analysed. Surgical biopsy, tumorectomy or mastectomy was indicated for malignancy or poor correlation between SFNA or LCNB results and clinical or radiological findings. Values of diagnostic accuracy of both LCNB and SFNA were determined. The ratio benign surgical biopsies/malignant surgical biopsies (BB/CB) of the series was calculated. A total of 171 patients underwent surgical treatment; in 31 (18.1 %) a benign process or atypical ductal hyperplasia was the final diagnosis. The ratio BB/CB was 0.22. Sensitivity and specificity were 93.2 and 100 %, respectively, for LCNB, and 77.2 and 92.3 %, respectively, for SFNA with cytological analysis. Large-core needle biopsy provides more accurate diagnosis than SFNA in the management of nonpalpable breast lesions and obviates a surgical diagnostic procedure in a significant number of cases.

Adapting breast density classification from digitized to full-field digital mammograms

Mammographic density is strongly associated with breast cancer, being considered one of the most important risk indicators for the development of this type of disease. Likewise, the sensitivity of automatic breast lesion detection systems is significantly dependent on breast tissue characteristics. Therefore, the measurement of density is definitely useful for detecting breast cancer. The aim of this work is to adapt our previously developed automatic breast tissue density classification methodology for digitized mammograms to full-field digital mammograms (FFDM), as well as to evaluate the possible improvements and the classification results. After breast area extraction and peripheral enhancement, the method segments the breast area into fatty and dense tissue, then morphological and texture features from each class are extracted and finally FFDM are classified according to a standard qualitative criteria. Results show a strong correlation (κ=0.88) between automatic and expert assessments and a better classification correction percentage (CCP = 92%) compared to our earlier work.

Shear-wave elastography and immunohistochemical profiles in invasive breast cancer: Evaluation of maximum and mean elasticity values

PURPOSE To evaluate the correlations of maximum stiffness (Emax) and mean stiffness (Emean) of invasive carcinomas on shear-wave elastography (SWE) with St. Gallen consensus tumor phenotypes. METHODS We used an ultrasound system with SWE capabilities to prospectively study 190 women with 216 histologically confirmed invasive breast cancers. We obtained one elastogram for each lesion. We correlated Emax and Emean with tumor size, histologic type and grade, estrogen and progesterone receptors, HER2 expression, the Ki67 proliferation index, and the five St. Gallen molecular subtypes: luminal A, luminal B without HER2 overexpression (luminal B HER2-), luminal B with HER2 overexpression (luminal B HER2+), HER2, and triple negative. RESULTS Lesions larger than 20 mm had significantly higher Emax (148.04 kPa) and Emean (118.32 kPa) (P=0.005) than smaller lesions. We found no statistically significant correlations between elasticity parameters and histologic type and grade or molecular subtypes, although tumors with HER2 overexpression regardless whether they expressed hormone receptors (luminal B HER2+ and HER2 phenotypes) and triple-negative tumors had lower Emax and Emean than the others. We assessed the B-mode ultrasound findings of the lesions with some of the Emax or Emean values less than or equal to 80 kPa; only four of these had ultrasound findings suggestive of a benign lesion (two with luminal A phenotype and two with HER2 phenotype). CONCLUSIONS We were unable to demonstrate statistically significant differences among the subtypes of invasive tumors, although there appears to be a trend toward lower Emax and Emean in the aggressive phenotypes.

Silicone lymphadenopathy: an unusual cause of internal mammary lymph node enlargement.

A61-year-old woman was treated for a ductal invasive carcinoma in the right breast (mastectomy, axillary dissection and chemotherapy in 1990, and breast reconstruction with submuscular Becker silicone outside ⁄ saline inside double lumen prosthesis in 1994). In 2002, she presented with a progressive shrinkage of the right breast volume since 2000, after a traffic accident. A rupture of the implant was suggested. For this reason, a magnetic resonance imaging examination with specific prosthesis sequences and contrast-enhanced dynamic study was performed, showing both intracapsular rupture (linguini sign) and silicone bleeds outside the implant capsule (Fig. 1a,b). Although contrast-enhanced magnetic resonance study showed no appreciable enhancement, there was an evidence of a right internal mammary node measuring 1 cm (Fig. 1c). The significance of the node was uncertain, but on clinical considerations (possible regional spread of breast cancer), this lymph node was excised at the same time as the breast implant removal. Pathologic examination identified an histiocytic infiltrate with multinucleated giant cells, vacuoles, and refractive material consistent with silicone lymphadenopathy (Fig. 2). Magnetic resonance imaging was repeated 12 months after the initial study and showed no implant complications (a single lumen entirely gelfilled prosthesis reimplantation) or contrast enhancement. However, a new right internal mammary node measuring 0.8 cm was demonstrated (Fig. 3). Because of the similarity of its appearance to that seen before, the node was not removed. On follow-up 12 months