Low frequency of cancer occurrence in same breast quadrant diagnosed with lobular neoplasia at percutaneous needle biopsy

Lobular Breast Cancer: Histomorphology and Different Concepts of a Special Spectrum of Tumors

Simple Summary

Invasive lobular breast cancer (ILC) is a special type of breast cancer (BC) that was first described in 1941. The diagnosis of ILC is made by microscopy of tumor specimens, which reveals a distinct morphology. This review recapitulates the developments in the microscopic assessment of ILC from 1941 until today. We discuss different concepts of ILC, provide an overview on ILC variants, and highlight advances which have contributed to a better understanding of ILC as a special histologic spectrum of tumors.

Abstract

Invasive lobular breast cancer (ILC) is the most common special histological type of breast cancer (BC). This review recapitulates developments in the histomorphologic assessment of ILC from its beginnings with the seminal work of Foote and Stewart, which was published in 1941, until today. We discuss different concepts of ILC and their implications. These concepts include (i) BC arising from mammary lobules, (ii) BC growing in dissociated cells and single files, and (iii) BC defined as a morpho-molecular spectrum of tumors with distinct histological and molecular characteristics related to impaired cell adhesion. This review also provides a comprehensive overview of ILC variants, their histomorphology, and differential diagnosis. Furthermore, this review highlights recent advances which have contributed to a better understanding of the histomorphology of ILC, such as the role of the basal lamina component laminin, the molecular specificities of triple-negative ILC, and E-cadherin to P-cadherin expression switching as the molecular determinant of tubular elements in CDH1-deficient ILC. Last but not least, we provide a detailed account of the tumor microenvironment in ILC, including tumor infiltrating lymphocyte (TIL) levels, which are comparatively low in ILC compared to other BCs, but correlate with clinical outcome. The distinct histomorphology of ILC clearly reflects a special tumor biology. In the clinic, special treatment strategies have been established for triple-negative, HER2-positive, and ER-positive BC. Treatment specialization for patients diagnosed with ILC is just in its beginnings. Accordingly, ILC deserves greater attention as a special tumor entity in BC diagnostics, patient care, and cancer research.

Lobular neoplasia and invasive lobular breast cancer: Inter-observer agreement for histological grading and subclassification

Lobular neoplasia (LN), invasive lobular breast cancer (ILBC) and related pleomorphic variants represent a distinct group of neoplastic mammary gland lesions. This study assessed the inter-observer agreement of histological grading in a series of ILBC and LN. 54 cases (36x ILBC, 18x LN) were evaluated by 17 observers. 3978 classification calls on various histological features, including nuclear grade, proliferative activity (Ki67 immunohistochemistry, categorical scoring), histological grade and pleomorphism were obtained. Pairwise Cohen's kappa values were calculated and compared between various features and different observer subsets with variable histomorphological experience. In ILBC, pairwise inter-observer agreement for histological grade ranged from poor to almost perfect concordance and was higher in advanced and experienced histopathologists compared with beginners (P < 0.001). Agreement for proliferation (Ki67) ranged from slight to almost perfect concordance and was also higher in advanced and experienced histopathologists (P < 0.001). Considering different features, agreement for proliferation (Ki67) was superior to agreement for histological grade and nuclear grade, even among advanced and experienced histopathologists (P < 0.001). In LN, agreement for B-classification ranged from poor to almost perfect concordance and was higher in advanced and experienced histopathologists (P < 0.001). Considering different features, agreement for proliferation (Ki67 in LN) was superior to subclassification agreement based on conventional features, such as acinar distention and nuclear grade (P < 0.001). In summary, pairwise inter-observer concordance of histological grading of ILBC and LN is dependent on histomorphological experience. Assessment of proliferation by Ki67 immunohistochemistry is associated with favorable inter-observer agreement and can improve histological grading of ILBC as well as LN.

Is contralateral breast ultrasound worthwhile in preoperative staging of breast cancer?

BACKGROUND

Women with invasive breast cancer are at higher risk of contralateral synchronous cancer. This study aimed at determining if contralateral breast ultrasound (CBUS) examination should be routinely performed in the preoperative evaluation of breast cancer patients.

METHODS

This is a retrospective study of preoperative CBUS examinations performed between January 2012 and April 2015. The charts of patients presenting for biopsy of a Breast Imaging Reporting and Data System (BIRADS) 5 lesion and who had undergone a concomitant contralateral breast US examination were reviewed. Index tumor, lymph node status, American College of Radiology (ACR) breast density on mammogram, total scanning time, and results of CBUS were recorded.

RESULTS

Of the 3007 patients who underwent breast biopsies during the study period, 360 patients met the inclusion criteria. Index mass size was 19 ± 10 mm. CBUS examination led to 76 biopsies, of which 12 were positive in 11 patients. Detection rate for mammographically occult contralateral invasive cancers was 3.1% (11/360). Contralateral lesion size was 13 ± 10 mm. Breast density was rated ACR C/D for nine women and ACR B for two. In the ACR C/D subgroup (82%), the contralateral cancer detection rate was 4.1%. Average additional scanning time spent required to perform CBUS examination was 3.1 ± 4.9 min. Patients diagnosed with contralateral invasive breast cancer underwent surgery and/or chemotherapy. The treatment strategy was changed in all 11 patients after the detection of a second primary cancer.

CONCLUSION

Preoperative CBUS is effective and most beneficial with women presenting ACR C/D breast density. Given its impact on decreasing future morbidity, its routine use should be considered to improve quality healthcare for women diagnosed with breast cancer.

Papillomas of the breast: factors associated with underestimation

The distinction between benign and malignant papilloma of the breast through percutaneous needle biopsy can be difficult because of limited samples; the underestimation rate can be up to 25%. The aim of this study is to identify clinical and histological factors associated with underestimation, invasive ductal carcinoma, or ductal in-situ carcinoma (DCIS) of the breast found in surgical specimens from papillary lesions. This may contribute toward selection of patients for a follow-up strategy without the need for surgical excision. From a database of 3563 patients, we identified 85 with intraductal papilloma between 2007 and 2013 who had undergone breast-imaging studies, percutaneous needle biopsy, and surgical resection of the lesion. Central papillomas normally present with a palpable mass, whereas peripheral papillomas generally do not have clinical manifestations (microcalcifications); both central and peripheral papillomas were related to atypical lesions, 13.5 and 15.4%, respectively. Among the 59 cases of central papillomas, there were four cases of underestimation, three DCIS and one invasive ductal carcinoma (6.8%). Among the 26 cases of peripheral papillomas, there was one case of DCIS (3.8%), with a total underestimation rate of 5.8%; all underestimated lesions measured more than 1 cm. The median size was 11 mm at mammography and 19 mm at ultrasound. Our data suggest that lesions less than 1 cm in size, without atypia and concordant imaging and clinical findings, may not require surgical resection.

Vacuum-assisted complete excision of solid intraductal/intracystic masses and complex cysts: Is follow-up necessary?

INTRODUCTION

Management of complex cysts and benign intraductal/intracystic masses is controversial. The aim of this study was to determine if the complete removal of the complex cyst lesions with ultrasound-guided vacuum-assisted excision (US-VAE) is sufficient for their safe management when the histological diagnosis obtained at biopsy is benign.

SUBJECTS AND METHODS

This is a single institution retrospective study performed on patients who underwent breast biopsy between April 2007 and September 2013. Patients with complete removal of complex cyst lesion of a BIRADS 4 lesion by US-VAE that obtained a benign diagnosis were included. Size, morphology, histological diagnosis, and surgical or imaging follow-up of the lesions were analyzed.

RESULTS

During the study period, 131 lesions met the inclusion criteria. Benign papilloma represented 32% (42/131) of the lesions; the remaining lesions had various benign diagnoses. Mean size of the solid mass or the cysts' thickest septum was 7 mm (range, 2-24). Mean imaging follow-up was 34.9 months (24-99 months) in 115 lesions. No recurrence or malignancy in the post-biopsy bed were observed during follow-up. Eleven lesions (8.4%) underwent surgery as follow-up: no cancer was found, but two lesions demonstrated atypia.

CONCLUSIONS

Complex cyst lesion image completely excised with US-VAE and with a benign histology at biopsy might not require further imaging follow-up or surgery and a return to routine screening can be safely recommended. In a world where healthcare delivery and accessibility is important, elimination of unnecessary follow-ups is pertinent given its lower cost and lesser social impact.

Core Breast Biopsies Showing Lobular Carcinoma In Situ Should Be Excised and Surveillance Is Reasonable for Atypical Lobular Hyperplasia

OBJECTIVE

The purpose of this article is to determine the upgrade rate to ductal carcinoma in situ (DCIS) or invasive carcinoma at excision at the same site after percutaneous breast biopsy findings of atypical lobular hyperplasia (ALH) or lobular carcinoma in situ (LCIS) using current imaging and strict pathologic criteria.

MATERIALS AND METHODS

From January 2006 through September 2013, 32,960 breast core biopsies were performed; 1084 (3.3%) core biopsies found ALH or classic LCIS. For 447 lesions in 433 women, this was the only high-risk lesion at that site, with no ipsilateral malignancy, and results of excision were available.

RESULTS

Among the 447 lesions, 22 (4.9%) were malignant at excision, including 10 invasive carcinomas (two grade 2 and eight grade 1; all node negative) and 12 DCIS. The upgrade rate of LCIS was 9.3% (10/108; 95% CI, 5.1-16.2%) and that of ALH was 3.5% (12/339; 95% CI, 2.0-6.1%; p = 0.02). After excluding five cases with radiologic-pathologic discordance and reclassifying one core from ALH to LCIS at review, the upgrade rate for LCIS remained higher (8.4%; 9/107; 95% CI, 4.5-15.2%) than that for ALH (2.4%; 8/335; 95% CI, 1.2-4.6%; p = 0.01).

CONCLUSION

Excision is recommended for LCIS on core biopsy because of its 8.4-9.3% upgrade rate. Excluding discordant cases, patients with other high-risk lesions or concurrent malignancy, the risk of upgrade of ALH was 2.4%. Surveillance at 6, 12, and 24 months can be performed in lieu of excision because a short delay in diagnosis of the few malignancies is not expected to cause harm.

Is clinical breast examination important for breast cancer detection?

BACKGROUND

Screening clinical breast examination (cbe) is controversial; the use of cbe is declining not only as a screening tool, but also as a diagnostic tool. In the present study, we aimed to assess the value of cbe in breast cancer detection in a tertiary care centre for breast diseases.

METHODS

This retrospective study of all breast cancers diagnosed between July 1999 and December 2010 at our centre categorized cases according to the mean of detection (cbe, mammography, or both). A cbe was considered "abnormal" in the presence of a mass, nipple discharge, skin or nipple retraction, edema, erythema, peau d'orange, or ulcers.

RESULTS

During the study period, a complete dataset was available for 6333 treated primary breast cancers. Cancer types were ductal carcinoma in situ (15.3%), invasive ductal carcinoma (75.7%), invasive lobular carcinoma (9.0%), or others (2.2%). Of the 6333 cancers, 36.5% (n = 2312) were detected by mammography alone, 54.8% (n = 3470) by mammography and cbe, and 8.7% (n = 551) by physician-performed cbe alone (or 5.3% if considering ultrasonography). Invasive tumours diagnosed by cbe alone were more often triple-negative, her2-positive, node-positive, and larger than those diagnosed by mammography alone (p < 0.05).

CONCLUSIONS

A significant number of cancers would have been missed if cbe had not been performed. Compared with cancers detected by mammography alone, those detected by cbe had more aggressive features. Clinical breast examination is a very low-cost test that could improve the detection of breast cancer and could prompt breast ultrasonography in the case of a negative mammogram.

Surgical Outcomes of Lobular Neoplasia Diagnosed in Core Biopsy: Prospective Study of 316 Cases

BACKGROUND

Management recommendations for lobular neoplasia (LN) including lobular carcinoma-in-situ (LCIS) and atypical lobular hyperplasia (ALH) diagnosed in core biopsies (CB) are controversial. Our aim was to prospectively identify a subset of patients who do not require subsequent surgical excision (SE).

PATIENTS AND METHODS

All patients diagnosed with LN on CB were enrolled and referred for SE. Cases with coexistent ductal carcinoma-in-situ or invasive carcinoma were excluded. Cases with coexistent ductal atypia (LN-DA) and LCIS variants (LN-V) were separated from pure classic LN (LN-C). Dedicated breast pathologists and radiologists reviewed cases with careful imaging/pathology correlation.

RESULTS

Of 13,772 total percutaneous breast CB procedures, 302 of 370 patients diagnosed with LN underwent SE. Upgrade to carcinoma was present in 3.5% (8/228) LN-C, 26.7% LN-V (4/15), and 28.3% LN-DA (15/53). Calcifications were the imaging target for 180 (79%) of 228 LN-C cases; 7 were associated with upgrade (3.9%). Upgrades were rare for mass lesions (1/32) and magnetic resonance imaging-targeted lesions (0/14). Upgrades were similar for ALH and LCIS (3.4% vs. 4.5%). During postsurgical follow-up (mean, 34.5 months), 6.5% LN-C patients developed carcinoma in either breast.

CONCLUSION

Although LN with nonclassic morphology or with associated ductal atypia requires SE, this can be avoided in LN-C diagnosed on CB targeting calcifications when careful imaging/pathology correlation is applied. Until larger numbers are studied, excising LN-C diagnosed as masses or magnetic resonance imaging-detected lesions may be prudent. Regardless of their selection for surgical management, LN patients need close surveillance in view of their long-term risk of breast cancer.

The radiological features, diagnosis and management of screen-detected lobular neoplasia of the breast: Findings from the Sloane Project

OBJECTIVES

To investigate the radiological features, diagnosis and management of screen-detected lobular neoplasia (LN) of the breast.

MATERIALS AND METHODS

392 women with pure LN alone were identified within the prospective UK cohort study of screen-detected non-invasive breast neoplasia (the Sloane Project). Demography, radiological features and diagnostic and therapeutic procedures were analysed.

RESULTS

Non-pleomorphic LN (369/392) was most frequently diagnosed among women aged 50-54 and in 53.5% was at the first screen. It occurred most commonly on the left (58.0%; p = 0.003), in the upper outer quadrant and confined to one site (single quadrant or retroareolar region). No bilateral cases were found. The predominant radiological feature was microcalcification (most commonly granular) which increased in frequency with increasing breast density. Casting microcalcification as a predominant feature had a significantly higher lesion size compared to granular and punctate patterns (p = 0.034). 326/369 (88.3%) women underwent surgery, including 17 who underwent >1 operation, six who had mastectomy and six who had axillary surgery. Two patients had radiotherapy and 15 had endocrine treatment. Pleomorphic lobular carcinoma in situ (23/392) presented as granular microcalcification in 12; four women had mastectomy and six had radiotherapy.

CONCLUSION

Screen-detected LN occurs in relatively young women and is predominantly non-pleomorphic and unilateral. It is typically associated with granular or punctate microcalcification in the left upper outer quadrant. Management, including surgical resection, is highly variable and requires evidence-based guideline development.

Management of atypical lobular hyperplasia, atypical ductal hyperplasia, and lobular carcinoma in situ

Atypical hyperplasia and lobular carcinoma in situ are rare proliferative breast lesions, growing inside ducts and terminal ducto-lobular units. They represent a marker of increased risk for breast cancer and a non-obligate precursor of malignancy. Evidence available on diagnosis and management is scarce. They are frequently found incidentally associated with other lesions, but can be visible through mammography, ultrasound or magnetic resonance. Due to the risk of underestimation, surgical excision is often performed. The analysis of imaging and histopathological characteristics could help identifying low-risk cases, for which surgery is not necessary. Chemopreventive agents can be used for risk reduction. Careful imaging follow up is mandatory; the role of breast MRI as screening modality is under discussion.

Underestimation rate of lobular intraepithelial neoplasia in vacuum-assisted breast biopsy

OBJECTIVES

To evaluate the underestimation rate and clinical relevance of lobular neoplasia in vacuum-assisted breast biopsy (VABB).

METHODS

A total of 161 cases of LN were retrieved from 6,435 VABB. The histological diagnosis was ALH (atypical lobular hyperplasia) in 80 patients, LCIS (lobular carcinoma in situ) in 69 patients and PLCIS (pleomorphic lobular carcinoma in situ) in 12 patients. Seventy-six patients were operated on within 2 years after VABB and 85 were clinically and radiologically monitored. The mean follow-up was 5.2 years, and the prevalence of malignancy was evaluated in the group of 85 patients.

RESULTS

The clinico-pathological characteristics significantly favouring surgery were larger lesions, occurrence of a residual lesion following VABB and histological LCIS and PLCIS subtypes. The VABB underestimation rate as compared to surgery was 7.1% for ALH, 12% for LCIS and 50% for PLCIS. Overall, 11 of the 148 patients included in this survival analysis developed an ipsilateral tumour.

CONCLUSION

Although obtained retrospectively in a relatively small series of patients, our data suggest that only patients with a diagnosis of PLCIS in VABB should be treated with surgery, whereas patients with ALH and LCIS could be monitored by clinical and radiological examinations.

KEY POINTS

• The treatment of ALH and LCIS in VABB is still debated • Some authors favour radical treatment and others a more conservative approach • Only patients with PLCIS in VABB should be treated by surgery.