Expression of LGR5 in mammary myoepithelial cells and in triple-negative breast cancers.

Lineage tracing in mice indicates that LGR5 is an adult stem cell marker in multiple organs, such as the intestine, stomach, hair follicles, ovary, and mammary glands. Despite many studies exploring the presence of LGR5 cells in human tissues, little is known about its expression profile in either human mammary tissue or pathological lesions. In this study we aim to investigate LGR5 expression in normal, benign, and malignant lesions of the human breast using RNA in situ hybridization. LGR5 expression has not been observed in normal lactiferous ducts and terminal duct lobular units, whereas LGR5-positive cells have been specifically observed in the basal myoepithelium of ducts in the regenerative tissues, ductal carcinoma in situ, and in ducts surrounded by invasive cancer cells. These findings suggest LGR5 marks facultative stem cells that are involved in post injury regeneration instead of homeostatic stem cells. LGR5 positivity was found in 3% (9 of 278 cases) of invasive breast cancers (BC), and it showed positive associations with higher histologic grades (P = 0.001) and T stages (P < 0.001), while having negative correlations with estrogen receptor (P < 0.001) and progesterone receptor (P < 0.001) expression. Remarkably, all LGR5-positive BC, except one, belong to triple-negative BC (TNBC), representing 24% (9 of 38 cases) of all of them. LGR5 histoscores have no correlations with EGFR, CK5/6, Ki-67, or P53 expression. Additionally, no ß-catenin nuclear localization was observed in LGR5-positive BC, indicating that canonical Wnt pathway activation is less likely involved in LGR5 expression in BC. Our results demonstrate that LGR5 expression is induced in regenerative conditions in the myoepithelium of human mammary ducts and that its expression is only observed in TNBC subtype among all invasive BC. Further studies regarding the functional and prognostic impact of LGR5 in TNBC are warranted.

Breast Cancer Risk Associated With Benign Intraductal Papillomas Initially Diagnosed on Core Needle Biopsy.

BACKGROUND: The long-term risk for patients with benign intraductal papillomas (IDPs) on core needle biopsy (CNB) who are not upgraded on excision is not well-defined. The goal of this study was to determine the cumulative breast cancer (BC) incidence for patients with benign IDP on CNB. MATERIALS AND METHODS: There were 152 benign IDPs diagnosed on CNB between 2003 and 2008. Radiology and pathology data were reviewed by breast radiologists and pathologists. Clinical follow-up was obtained from the electronic medical record (Epic). RESULTS: Excision results were: 96 (63%) not upgraded, 9 (6%) with BC on excision (6 ductal carcinoma in situ, 3 invasive carcinoma), and 5 (3%) lacked correlation with the CNB site. Excision reports were unavailable for 42 (28%). Excluding cases with Breast Imaging Reporting and Data System (BI-RADS) 5 or discordant imaging, there were 6 (4%) true upgrades (all ductal carcinoma in situ). After the exclusion of patients with other major risk factors, follow-up was available for 55 of 58 patients with benign IDPs, and 8 (14%) developed BC after a median of 112 months (range, 11-159 months). None of the benign IDP patients without an excision report developed BC after a median of 97 months (range, 5-164 months). CONCLUSIONS: The upgrade rate for benign IDP diagnosed on CNB was 4%, similar to recent studies. The cumulative BC incidence for those who were not upgraded and who had no history of BC was 14% at a median of 9 years. When combined with patients without an excision pathology report, the overall BC incidence was 9%. The findings support continued breast cancer surveillance in this patient population.

Intraductal papilloma arising from the accessory parotid gland: A case report and literature review.

RATIONALE: Intraductal papillomas of the accessory parotid glands are extremely rare benign tumors that are most commonly derived from minor salivary glands and are easily misdiagnosed as other diseases. Studying these lesions by pathology and immunohistochemistry can raise awareness of the disease, reduce the rate of misdiagnosis, and provide more precise treatments. PATIENT CONCERNS: A 35-year-old man first presented to our hospital with a 6-month history of a painless mass on his left parotid gland. DIAGNOSES: The patient was diagnosed with intraductal papilloma of the accessory parotid gland by pathology and immunohistochemistry. INTERVENTIONS: The mass was completely resected. OUTCOMES: After 2 years of postoperative follow-up, the patient recovered well without recurrence. LESSONS: Intraductal papilloma of the accessory parotid gland is very rare, and can easily be misdiagnosed as sialadenoma papilliferum, inverted ductal papilloma, or papillary cystadenoma, among others. It is necessary to analyze its pathology and immunohistochemistry in comparison with other diseases. Early excision and long-term follow-up are necessary to provide optimal treatment and to better understand the pathological processes of intraductal papilloma.

Molecular alterations in lesions of anogenital mammary-like glands and their mammary counterparts including hidradenoma papilliferum, intraductal papilloma, fibroadenoma and phyllodes tumor.

Lesions affecting anogenital mammary-like glands (AGMLG) are histopathologically very similar to those seen in the breast but whether this morphological similarity is also reflected at the genetic level is unknown. To compare the underlying molecular mechanisms in lesions of AGMLG and their mammary counterparts, we analyzed the mutational profile of 16 anogenital neoplasms including 5 hidradenomas papilliferum (HP), 1 lesion with features of HP and fibroadenoma (FA), 7 FA, 3 phyllodes tumors (PhT)) and 18 analogous breast lesions (6 intraductal papillomas (IDP), 9 FA, and 3 PhT) by high-coverage next generation sequencing (NGS) using a panel comprising 50 cancer-related genes. Additionally, all cases were analyzed for the presence of a mutation in the MED12 gene. All detected mutations with allele frequencies over 20% were independently validated by Sanger sequencing (concordance: 100%). Mutations in PIK3CA, AKT1, MET, ABL1 and TP53 genes were found in lesions of AGMLG and also their mammary counterparts. The PI3K-AKT cascade plays a role in tumors arising at both sites. It appears that some histopathologically similar anogenital and breast lesions develop along similar molecular pathways.

Papillary Lesions of the Breast: An Update.

CONTEXT: -Papillary lesions of the breast, characterized by the presence of arborescent fibrovascular cores that support epithelial proliferation, constitute a heterogeneous group of neoplasms with overlapping clinical manifestation and histomorphologic features, but may have divergent biological behavior. These lesions are exclusively intraductal neoplasms, although an invasive carcinoma may rarely have a predominantly papillary architecture. Although recognition of a papillary architecture is typically not challenging, the histologic distinction of these entities is not always straightforward. Historically, different terminologies and variable criteria have been proposed for a given entity by various authorities. The difficulty in classifying these lesions has been further confounded by the scarcity of data and the heterogeneity across different studies with regard to the molecular genetic characteristics of this group of lesions. OBJECTIVE: -To provide an overview focusing on the current concepts in the diagnosis and classification of papillary lesions of the breast incorporating recent molecular genetic advances. DATA SOURCES: -Data were obtained from pertinent peer-reviewed English-language literature. CONCLUSIONS: -The recent evolution of molecular techniques has enhanced our knowledge of the pathogenesis of papillary carcinomas of the breast. This, along with emerging outcome studies, has led to prognosis-based reclassification of some of these entities. Additional studies focusing on the molecular signatures are needed to identify potential decision tools to further stratify these lesions with respect to prognostic significance.

Mammary ductoscopy and watchful follow-up substitute microdochectomy in patients with bloody nipple discharge.

PURPOSE: In order to evaluate the diagnostic and therapeutic potential of mammary ductoscopy and watchful follow-up for treating bloody nipple discharge, we investigated the incidence of cancer evolving from the location related to the affected duct and the disappearance of nipple discharge. PATIENTS AND METHODS: Between April 1998 and March 2008, we assessed 709 lesions among 624 patients without a diagnosis of malignancy at the time of 6 months after mammary ductoscopy. The median follow-up time was 5.5 years. We reviewed the subjects' charts retrospectively and investigated the dates on which discharge-related cancer was diagnosed and the disappearance of discharge was noted after the initial examination with mammary ductoscopy. RESULTS: The incidence of cancer evolving from the location related to the pathological duct was 11 % (78/709). Nipple discharge disappeared in 480 (85.1 %) of the 564 followed up lesions, with the exception of 78 breast cancers and 67 resected benign lesions. The rate of disappearance for nipple discharge in the cases of intraductal papilloma at the first examination was 82.5 %. In cases in which no obvious lesions were observed on mammary ductoscopy, there was a 90 % probability that the nipple discharge would disappear, and the rate of evolving breast cancer in the cases of atypical papillary lesions at the first examination was significantly higher than that observed in the cases of intraductal papilloma, at 50 and 8.9 %, respectively. CONCLUSIONS: Information revealed by mammary ductoscopy is useful for differentiating patients who should be subjected to intensive examinations and those who should expect disappearance of their discharge. Mammary ductoscopy and watchful follow-up can substitute microdochectomy in patients with bloody nipple discharge.

Morphogenesis of the papillary lesions of the breast: phenotypic observation.

Papillary lesions of the breast are a heterogeneous group of diseases characterised by the presence epithelial proliferation supported by fibrovascular stalks. Normal breast tissue does not show papillary morphology and the mechanisms underlying papillary morphogenesis in breast tumours remain poorly understood. Current clinical evidence indicates an indolent behaviour of malignant papillary breast tumours. Herein, we present some phenotypic features that may explain the development of papillary morphology of breast lesions. Active papillary morphogenesis, which appears to reflect a unique mechanism involving interaction between epithelial and mesenchymal elements, is best appreciated in intraductal papilloma and papillary carcinoma. Morphological evidence suggests papillary morphogenesis during oncogenesis is a dynamic process with variable degrees of papillary differentiation among the same lesion and between primary and metastatic tumours. Secondary papillary-like architecture of non-papillary breast lesions exists. Further studies of the molecular mechanisms underlying papillary morphogenesis in the breast and its association with a better outcome are warranted.

Collagen Type XI Alpha 1 Expression in Intraductal Papillomas Predicts Malignant Recurrence.

Despite the progress achieved in the treatment of breast cancer, there are still many unsolved clinical issues, being the diagnosis, prognosis, and treatment of papillary diseases, one of the highest challenges. Because of its unpredictable clinical behavior, treatment of intraductal papilloma has generated a great controversy. Even though considered as a benign lesion, it presents high rate of malignant recurrence. This is the reason why there are clinicians supporting a complete excision of the lesion, while others support an only expectant follow-up. Previous results of our group suggested that procollagen 11 alpha 1 (pro-COL11A1) expression correlates with infiltrating phenotype in breast lesions. We analyzed the correlation between expression of pro-COL11A1 in intraductal papilloma and their risk of malignant recurrence. Immunohistochemistry of pro-COL11A1 was performed in 62 samples of intraductal papilloma. Ten out 11 cases relapsed as carcinoma presents positive staining for COL11A1, while just 17 out of 51 cases with benign behaviour present immunostaining. There were significant differences (P < 0.0001) when comparing patients with malignant recurrence versus nonmalignant relapse patients. These data suggest that pro-COL11A1 expression is a highly sensitive biomarker to predict malignant relapse of intraductal papilloma and it can be used as indicative factor for prevention programs.

Intraductal fibroadenoma under the nipple in an 11-year-old female.

Recently, Chung et al. have reported the detailed clinicopathological features of an extremely rare case sharing similar histopathological characteristics with fibroadenomas, phyllodes tumours, intraductal papillomas or ductal adenomas, given the name of intraductal fibroadenomatosis, as an unusual variant of intracanalicular fibroadenoma. Herein we demonstrated a very unusual case of intraductal fibroadenoma of the breast with admixture of components of intracanalicular type fibroadenoma or benign phyllodes tumour and a smaller amount of intraductal papilloma, occupying the one duct and some adjacent ductules, presenting as a well-demarcated nodule.

Combined evaluation of CK5/6, ER, p63, and MUC3 for distinguishing breast intraductal papilloma from ductal carcinoma in situ.

The differentiation of intraductal papilloma (IDP) in the breast from ductal carcinoma in situ (DCIS) is sometimes difficult. Fifty papillary lesions (25 DCIS and 25 IDP) were immunohistochemically examined using a panel of antibodies, including CK5/6, ER, p63, Ki-67, chromogranin A, synaptophysin, neuron specific enolase, CD56, MUC1, MUC3, CD44, p21, p27, and p53. The immunohistochemical staining pattern of each antibody was evaluated using the Allred scoring system. Then, the area under curve (AUC) for each antibody was computed by receiver operating characteristic (ROC) analysis. DCIS typically showed high scores for ER and MUC3 reactivity compared with IDP, and the AUC for ER and MUC3 were 0.941 and 0.908, respectively. In contrast, IDP showed high scores for CK5/6 and p63 reactivity compared with DCIS, and the AUC for CK5/6 and p63 were 1.00 and 0.954, respectively. We devised a 'Differential Index' (DI) using the following formula: [S(ER) + S(MUC3)]/[S(CK5/6) + S(p63) + 1]. The distributions of the DI for IDP and DCIS did not overlap when the cutoff value was placed arbitrarily at DI = 1.0. From these results, it is concluded that a panel of four CK5/6, ER, p63, and MUC3 antibodies provide valuable information for differentiating IDP from DCIS.

Immunohistochemical profile of the estrogen and progesterone receptors in mammary benign lesions.

UNLABELLED: The immunohistochemical diagnosis for estrogen and progesterone receptors must be carried out in the tracking of every primary tumor, benign or malign, especially in the case of in situ carcinoma. MATERIAL AND METHOD: We have studied the expression of estrogen and progesterone receptors in benign lesions, identifying phenotypes depending on the presence of estrogen and progesterone receptors. RESULTS: The result "positive" or "negative" in the report sent to the doctor is not sufficient, the inclusion of the total score in the case of a positive result, the clone used, the usage / non-usage of antigenic exposure and also the quality control being necessary. The benign mammary lesions occur in the context of a hormonal imbalance, which, in the long run runs the risk of developing a mammary carcinoma. CONCLUSION: The further study of the hormonal spectrum of those lesions, considered as pre-malignant, may lead to the identification of some groups of hyperplastic lesions, presenting a high risk for developing a mammary cancer.

Glucose transporter expression of intraductal papilloma of the breast detected by fluorodeoxyglucose positron emission tomography.

A 40-year-old woman discovered through palpation a tumor in the upper lateral quadrant of the left mammary gland. Mammography, ultrasonography (US), and magnetic resonance imaging (MRI) showed a 10 mm diameter tumor. Fluorine-18 fluorodeoxyglucose positron emission tomography ((18)F-FDG-PET) showed abnormal accumulation in the detected tumor, and the maximum standardized uptake value was 2.2. The patient underwent tumor resection. The postoperative histopathological finding was intraductal papilloma. The intraductal papilloma showed strong expression of glucose transporter (GLUT)-4 on membrane and/or cytoplasm, and weak expression of GLUT-1 and GLUT-3 by immunohistochemistry. This case suggests that other glucose transporters (e.g., GLUT-4), other pathological factors, and cytokines may have a close relation with (18)F-FDG accumulation in intraductal papilloma more than GLUT-1 or GLUT-3 expression.

Microdochectomy in the management of pathologic nipple discharge.

BACKGROUND: There is a debate in the literature whether a pathologic nipple discharge is a distinct sign of breast carcinoma. Our own results obtained by the use of microdochectomy as a minimally invasive operative procedure in 184 patients with pathologic nipple discharge were analysed. The aim of this retrospective 20-year study was to assess the efficacy of microdochectomy in detecting early stages of intraductal breast carcinoma. PATIENTS AND METHODS: The study included data on 184 patients aged 24-77 years (median 46.6) divided into two groups of premenopausal (n = 123) and postmenopausal (n = 61) women. There were 139 patients with unilateral single-duct sanguinolent discharge and 45 patients with other types of nipple discharge. The operative procedure consisted of the discharging duct excision by use of a guide probe, preceded by cytology and ductography studies. RESULTS: Histopathology of the excised ducts revealed only three carcinomas in premenopausal women and ten carcinomas in postmenopausal women. In a total of 13 carcinomas, there were 4 ductal carcinomas in situ, detected in patients aged 41-72 (median 66) years. Twelve carcinomas were associated with sanguinolent nipple discharge. Papilloma was the most common histology finding (56.5%). CONCLUSION: Results of the study suggested mainly the association of sanguinolent single-duct nipple discharge and papilloma, whereas the rate of malignancies detected (7.0%) was consistent with literature reports. Microdochectomy proved to be a highly efficient operative method free from any impairment of the breast integrity. Conservative treatment with close clinical monitoring of the patient with cytology and ultrasonographic assessment might be possible in selected cases.

[Clinicopathologic and immunohistochemical study of 187 cases of intraductal papillary neoplasm of breast].

OBJECTIVE: To evaluate the diagnostic approach and criteria for intraductal papillary neoplasms of breast. METHODS: According to the criteria of 2003 WHO classification, 187 cases of intraductal papillary neoplasm of breast were identified and enrolled into the study. The clinical and histologic features were reviewed and immunohistochemical study for CD10, p63, CK14, CK5/6, CK7, MGB1 and p53 were carried out on 53 cases. RESULTS: Amongst the 187 cases studied, there were 128 cases of intraductal papilloma, 16 cases of atypical intraductal papilloma and 43 cases of intraductal papillary carcinoma. They showed a spectrum of morphologic features including epithelial and stromal hyperplasia and secondary changes. The expression of myoepithelial markers, including CD10 and p63, significantly decreased in ascending order from intraductal papillomas, atypical intraductal papillomas and intraductal papillary carcinomas (P < 0.001). The expression of basal cell markers, including CK5/6 and CK14, showed a mosaic pattern in benign lesions and significantly decreased or was absent in atypical and carcinomatous lesions (P < 0.001). In contrast, the luminal cell marker CK7 expressed in the three groups with no statistically significant difference (P = 0.06). On the other hand, the expression of MGB1 in intraductal papillary carcinomas was much lower than that in the other two groups (P = 0.002 and P = 0.007). The staining for p53 was negative in all of the three groups. CONCLUSIONS: Intraductal papillary neoplasms of breast represent a heterogeneous group of lesions with various morphologic appearances. Correlation with immunostaining results for myoepithelial markers, basal-type cytokeratins and luminal epithelial markers are helpful in arriving at a definitive diagnosis.

A useful immunohistochemical approach to evaluate intraductal proliferative lesions of the breast and to predict their prognosis.

An examination was performed on 16 intraductal proliferative breast lesions diagnosed as intraductal papillomas (IP) or usual ductal hyperplasia (UDH), which were followed up for more than 3 years. An immunohistochemical marker panel combining myoepithelial markers, high-molecular-weight keratin (HMWK) and neuroendocrine markers was used. Two of 11 IP cases were re-evaluated as atypical ductal hyperplasia (ADH) and ductal carcinoma in situ (DCIS). These cases developed breast cancer after the first operation. One IP case showed repeated recurrences. None of the other IP and UDH cases had breast cancer or recurrence. The ADH, DCIS and the recurrent IP showing a solid growth lacked myoepithelia, but the recurrent IP expressed HMWK, immunohistochemically. Interestingly, these three lesions were weakly positive for neuroendocrine markers. All other IPs and UDHs, including lesions having solid components, were negative for neuroendocrine markers, and most of them were positive for myoepithelial markers and/or HMWK. A combination of the above immunohistochemical markers seems useful to evaluate intraductal proliferative lesions and to predict their prognosis. In particular, intraductal proliferative lesions with solid components exhibiting positivity for neuroendocrine markers should be followed up carefully to monitor breast cancer risk or recurrence.

Evaluation of CD56 and CD57 immunostainings for discrimination between endocrine ductal carcinoma in situ and intraductal papilloma.

Endocrine ductal carcinoma in situ (E-DCIS) is an intraductal carcinoma characterized by endocrine features and expression of neuroendocrine markers. E-DCIS and intraductal papilloma (IDP) resemble in their clinical features. However, the former is an intraductal carcinoma, and the latter is an intraductal benign lesion. It is sometimes difficult to distinguish E-DCIS from IDP because both can show near solid intraductal cellular proliferation. Discrimination between lesions is important not only histopathologically, but also clinically. This study aimed to evaluate the applicability of CD56 and CD57 for the discrimination between E-DCIS and IDP. Specimens were obtained from 17 E-DCIS patients as the subject group, and 27 IDP patients as the control group, diagnosed in St Marianna University Hospital. E-DCIS was diagnosed using Chromogranin A, Synaptophysin, and Grimelius stainings by the premise of histopathological features. These specimens were subjected to CD56, CD57 immunostainings. Staining results were compared between E-DCIS and IDP. In our study, CD56 revealed significant differences for distinguishing E-DCIS from IDP as determined by Fisher's test (cutoff: not less than 33-67%< immunopositivity, P < 0.05). We found that not only E-DCIS but also IDP revealed immunopositivity for CD56. However, it is considered that E-DCIS diagnosis is possible by diffuse immunopositivity of CD56 after having been based on histopathology.

Diagnostic evaluation of papillary lesions of the breast on core biopsy.

The management of asymptomatic intraductal papillary lesions of the breast diagnosed on core biopsy poses a challenge for patients and clinicians, as the distinction between common benign lesions and atypical or malignant varieties may be difficult without formal excision. The aim of this study was to determine whether a combination of histopathologic and biomarker features could be used to accurately identify benign papillary lesions on core biopsy. An inclusive group of 127 excised papillary lesions was characterized by detailed histopathologic review and immunohistochemical staining for the basal markers cytokeratin 5/6 (CK5/6) and P63 and the proliferation marker Ki67. Comparison of benign, atypical, and malignant lesions revealed that the combination of broad, sclerotic fibrovascular cores, and epithelial CK5/6 staining was most commonly seen in benign papillomas. Ki67 staining revealed striking intralesional heterogeneity, but there was no difference between the high scores of benign, atypical, or malignant lesions (P=0.173). In a non-overlapping set of 42 cases, a binary classifier specifying benign lesions on the basis of thick fibrovascular cores and epithelial CK5/6 staining on core biopsy gave an overall misclassification rate of 4/42 (10%) when compared with the final excision diagnosis. Misclassified cases included 2/27 lesions ultimately diagnosed as benign and 2/2 atypical papillomas. All malignant lesions (n=13) were correctly assigned. The combined assessment of fibrovascular core thickness and CK5/6 staining on core biopsy distinguished benign from malignant papillary lesions, but did not separate benign from atypical cases. This approach may form a useful addition to the clinicopathologic evaluation of papillary lesions of the breast.

Usefulness of immunohistochemistry for differential diagnosis between benign and malignant breast lesions.

Immunohistochemistry (IHC) is routinely performed during pathology practice for various breast lesions. Hormone receptor and HER2 analysis for primary breast carcinoma and cytokeratin staining for sentinel lymph nodes analysis are widely conducted. In addition to those markers, there are several situations in which certain IHC staining is valuable as an ancillary tool. This manuscript will present three useful examples of IHC for making differential diagnosis between benign and malignant lesions. Case 1 is an intraductal papilloma with solid epithelial proliferation, for which diagnosis was resolved by myoepithelial markers and high-molecular-weight cytokeratins (HMWCKs). Case 2 is a noninvasive ductal carcinoma with solid and papillary morphology. Many cases with such morphology mimic benign papillomas, but expression of neuroendocrine markers may lead to the correct diagnosis. Case 3 is a benign complex sclerosing lesion, with recognition of a pseudoinvasive process by myoepithelial markers. Although IHC results were excellent in these cases, they are effective only for limited situations. It is important to use IHC with caution, and re-evaluation of histological findings on hematoxylin and eosin stain and clinicopathological correlation of each case is essential.