Pathological criteria and practical issues in papillary lesions of the breast - a review

Invasive papillary carcinoma of the breast

Invasive papillary carcinoma is a rare form of breast cancer that is more likely to occur in postmenopausal women. Previous studies have been limited to case reports and small retrospective studies, leading to low awareness of this type of tumor and difficult clinical management. According to the available literature, invasive papillary carcinoma exhibits unique pathological features and biological behaviors. Invasive papillary carcinoma is mostly luminal type, with a low rate of lymph node metastasis, which underlies its favorable prognosis. The effectiveness of adjuvant therapy in reducing tumor burden and improving prognosis in patients with invasive papillary carcinoma remains uncertain. Due to the rarity of the lesion, conducting prospective clinical trials is impractical. The use of biological models, such as organoids, can help alleviate the impact of the scarcity of this condition on research. In addition, invasive papillary carcinoma is affected by specific genomic events, and more extensive studies of gene expression profiling may provide molecular-level insights to make optimal therapeutic decisions.

Breast cancer risk in papilloma patients: Osteopontin splice variants indicate prognosis

BACKGROUND

Papillomas of the breast pose challenges for treatment decisions as their risk for transformation to breast cancer is low but not negligible. To spare low-risk patients the burden of substantial treatment side effects, prognostic indicators are needed for cancerous progression. The secreted metastasis mediator Osteopontin (OPN) is a marker for breast cancer aggressiveness, and its variants are prognosticators for transformation in diverse premalignant breast lesions. Here, we test whether the presence of OPN-c or OPN-exon-4 in papillomatous lesions may reflect progression risk.

METHODS

By immunohistochemistry, we analyze OPN-c and OPN-exon-4 in papillomas from 114 women as well as correlations between staining and progression. In departure from prior spliced OPN biomarker publications, we utilize novel monoclonal antibodies.

RESULTS

Fewer than 5% of OPN-c pathology score 0-1 (intensity) versus almost 18% of score 2-3 experienced cancer in follow-up. Nine of 12 women, who progressed, had pathology scores of 2-3 for OPN-c intensity at the time of initial diagnosis, and none had a score of 0. When developing a combined risk score from intensity plus percent positivity for OPN-c, the progression risk for patients with low score was 3.2%, for intermediate score was 5.7%, and for high score was 18.8%. Papillomas in patients, who were later diagnosed with cancer in the contralateral breast, displayed stronger staining positivity than non-progressors.

CONCLUSION

OPN splice variant immunohistochemistry on biopsies of breast papillomas will allow counseling of the patients on their risk to develop breast cancer at a later time.

Intraductal papillary carcinoma of breast with invasion: A nomogram and survival from the analysis of the SEER database

BACKGROUND

Intraductal papillary carcinoma (IPC) with invasion is a rare type of breast cancer. There have been few studies on its prognosis, and a nomogram that predicts the prognosis of the disease has not been described to date.

METHODS

Patients who were diagnosed with invasive IPC were screened from the Surveillance, Epidemiology, and End Results (SEER) database. The screened patients were randomly divided into a training cohort and a verification cohort at 7:3. A Cox proportional hazard regression model was performed to analyze the effects of different variables on the risk of death in invasive IPC. A nomogram was constructed to quantify the possibility of death. The concordance index (C-index), calibration plots, receiver operating characteristic (ROC) curves, and decision curves analysis (DCA) were used to verify the proposed model.

RESULTS

We included a total of 803 patients diagnosed with invasive IPC, including 563 patients in the training cohort and 240 patients in the validation cohort. The median follow-up times in the training cohort and validation cohort were 63 months (range, 2-155 months) and 61 months (range, 1-154 months), respectively. For all patients, the probability of death with invasive IPC was 1.4% within 5 years and 5.4% within 10 years. In multivariate analysis, sex, race, tumor size, lymph node status, type of treatment, and chemotherapy were related to the prognosis of invasive IPC. We constructed a nomogram to predict the possibility of death in patients with invasive IPC.

CONCLUSION

Patients with invasive IPC had a high survival rate. The proven nomogram was helpful to both patients and clinical decision makers.

Papillary lesions of the breast - review and practical issues

Papillary lesions of the breast represent a heterogeneous group of neoplasm featuring fibrovascular cores covered by epithelial cells with or without intervening myoepithelial cells. According to the World Health Organization classification of breast tumors, papillary lesions of the breast are further classified into intraductal papilloma (including intraductal papilloma with atypical ductal hyperplasia /ductal carcinoma in situ), papillary ductal carcinoma in situ, encapsulated papillary carcinoma, solid papillary carcinoma (in situ and invasive) and invasive papillary carcinoma. The overlapping morphological features and immunohistochemical profiles make accurate diagnosis of breast papillary lesion a challenge for pathologists. In this review, the morphological and relevant immunohistochemical features of papillary lesions are discussed, with further emphasis on some commonly encountered practical diagnostic issues. A simple diagnostic algorithm will be established. The relevant molecular characteristics will be discussed as well.

Breast papillomas in the United States: single institution data on underrepresented minorities with a multi-institutional update on incidence

PURPOSE

To assess the percentage of papillomas from all biopsies performed, comparing differences in patient age and race at a single institution. To assess trends in biopsied papillomas at institutions throughout the United States (US).

METHODS

This is a HIPPA-compliant IRB-approved single-institution (Southern1) retrospective review to assess race and age of all-modality-biopsied non-malignant papillomas as a percentage of all biopsies (percentage papillomas calculated as papilloma biopsies/all biopsies) from January 2012 to December 2019. To assess national variation, several academic or large referral centers were contacted to provide data regarding papilloma percentages, biopsy modalities, and trends in case numbers. Trends were estimated using the method of analysis of variance (ANOVA). Comparisons of differences in trends were assessed.

RESULTS

Southern1 institution demonstrated a significant association between race and percentage of papillomas (p < 0.0001). After adjustment for multiple comparisons with Bonferroni correction at 5% type I family error, the percentage of biopsied papillomas in Black and Asian patients remained significantly higher than in White patients (p < 0.0001 and p = 0.0032, respectively) using a Chi-square test. The regional variation in percentage of papillomas was found to be 3-9%. Southern1 institution showed a 7-year significant trend of increase in percentage of papillomas. Other institutions showed a decreasing trend (p < 0.05).

CONCLUSION

Black and Asian women had significantly higher papilloma percentages compared to white patients in our single institution review. This institution also showed a statistically significant trend of increasing percentage papillomas from 2012 to 2019. Multi-institutional survey found regional variation in percentage papillomas, ranging from 3% to 9%.

Papillary lesions of the breast

Papillary lesions of the breast represent a heterogeneous group of lesions including benign papillomas, papillomas with focal epithelial atypia, fully fledged ductal carcinoma in situ (DCIS) or lobular neoplasia, papillary DCIS, encapsulated papillary carcinomas without or with invasion, solid papillary carcinomas, and invasive papillary carcinomas. A micropapillary pattern characterized by lack of fibrous stalks within the papillae is observed in micropapillary DCIS and invasive micropapillary carcinoma. In addition, a variety of other rare breast lesions reveals a papillary architecture such as tall cell carcinoma with reversed polarity (TCCRP) and mucinous cystadenocarcinoma, adenomyoepithelioma, and secretory carcinoma. In addition, benign lesions such as usual ductal hyperplasia, apocrine metaplasia, gynecomastia, and juvenile papillomatosis may show a papillary or micropapillary architecture. Fragments of a benign papilloma in a breast biopsy are considered a lesion of uncertain malignant potential (B3 in the European classification) and excision is mostly recommended. Although the knowledge about molecular pathology of papillary breast lesions has increased, there is not sufficient evidence for diagnostically useful molecular features, yet. The aim of this review is to provide an update on papillary and micropapillary lesions with emphasis on problematic areas for daily diagnostic work including biopsies.

Detailed Morphologic Evaluation of Breast Papillary Lesions on Core Biopsy Is Critical for Accurate Classification and Clinical Management: The Experience of an Academic Institute

BACKGROUND

Distinguishing between a breast intraductal papilloma and a papillary lesion with atypia or malignancy can be very challenging on core biopsy. There has been a long ongoing debate over whether or not it is necessary for breast papillary lesions diagnosed on core biopsies to be surgically excised, and the upgrading rate after excision varies.

METHOD AND/OR RESULT

This study was carried out in a subspecialized academic pathology department, with well-formed criteria established among the faculty for the categorization of breast papillary lesions, with emphasis on the morphology evaluation of cellular features. A total of 320 breast core biopsies with follow-up excisions were identified. Of these, 286 cases had concordant results between the biopsy and excision, giving a concordance rate of 89.4%, with 98% concordance (143/146) in benign papilloma, 100% (111/111) in papillary carcinoma, and 51% (32/63) in papilloma with atypia. Of the upgraded cases, two were upgraded from benign to atypical, 11 from atypia to malignancy, and only one from benign to malignant. The overall average upgrading rate was 4.4% (14/320), with the critical upgrading (from benign to atypia or malignancy) rate of 0.94% (3/320). Downgrading was only identified in the group of papilloma with atypia, with 20 of 63 cases downgraded to benign papilloma on excision.

CONCLUSION

Our study indicates that surgical excision may not be necessary for all papillary lesions after detailed evaluation of the morphology on core biopsies. Assessing the morphological features of the epithelial cells is critical for the accurate classification and clinical management of papillary lesions.

A multicenter study of interobserver variability in pathologic diagnosis of papillary breast lesions on core needle biopsy with WHO classification

BACKGROUND

Papillary breast lesions (PBLs) comprise diverse entities from benign and atypical lesions to malignant tumors. Although PBLs are characterized by a papillary growth pattern, it is challenging to achieve high diagnostic accuracy and reproducibility. Thus, we investigated the diagnostic reproducibility of PBLs in core needle biopsy (CNB) specimens with World Health Organization (WHO) classification.

METHODS

Diagnostic reproducibility was assessed using interobserver variability (kappa value, κ) and agreement rate in the pathologic diagnosis of 60 PBL cases on CNB among 20 breast pathologists affiliated with 20 medical institutions in Korea. This analysis was performed using hematoxylin and eosin (H&E) staining and immunohistochemical (IHC) staining for cytokeratin 5 (CK5) and p63. The pathologic diagnosis of PBLs was based on WHO classification, which was used to establish simple classifications (4-tier, 3-tier, and 2-tier).

RESULTS

On WHO classification, H&E staining exhibited 'fair agreement' (κ = 0.21) with a 47.0% agreement rate. Simple classifications presented improvement in interobserver variability and agreement rate. IHC staining increased the kappa value and agreement rate in all the classifications. Despite IHC staining, the encapsulated/solid papillary carcinoma (EPC/SPC) subgroup (κ = 0.16) exhibited lower agreement compared to the non-EPC/SPC subgroup (κ = 0.35) with WHO classification, which was similar to the results of any other classification systems.

CONCLUSIONS

Although the use of IHC staining for CK5 and p63 increased the diagnostic agreement of PBLs in CNB specimens, WHO classification exhibited a higher discordance rate compared to any other classifications. Therefore, this result warrants further intensive consensus studies to improve the diagnostic reproducibility of PBLs with WHO classification.

A multicenter study of interobserver variability in pathologic diagnosis of papillary breast lesions on core needle biopsy with WHO classification

Background

Papillary breast lesions (PBLs) comprise diverse entities from benign and atypical lesions to malignant tumors. Although PBLs are characterized by a papillary growth pattern, it is challenging to achieve high diagnostic accuracy and reproducibility. Thus, we investigated the diagnostic reproducibility of PBLs in core needle biopsy (CNB) specimens with World Health Organization (WHO) classification.

Methods

Diagnostic reproducibility was assessed using interobserver variability (kappa value, κ) and agreement rate in the pathologic diagnosis of 60 PBL cases on CNB among 20 breast pathologists affiliated with 20 medical institutions in Korea. This analysis was performed using hematoxylin and eosin (H&E) staining and immunohistochemical (IHC) staining for cytokeratin 5 (CK5) and p63. The pathologic diagnosis of PBLs was based on WHO classification, which was used to establish simple classifications (4-tier, 3-tier, and 2-tier).

Results

On WHO classification, H&E staining exhibited ‘fair agreement’ (κ = 0.21) with a 47.0% agreement rate. Simple classifications presented improvement in interobserver variability and agreement rate. IHC staining increased the kappa value and agreement rate in all the classifications. Despite IHC staining, the encapsulated/solid papillary carcinoma (EPC/SPC) subgroup (κ = 0.16) exhibited lower agreement compared to the non-EPC/SPC subgroup (κ = 0.35) with WHO classification, which was similar to the results of any other classification systems.

Conclusions

Although the use of IHC staining for CK5 and p63 increased the diagnostic agreement of PBLs in CNB specimens, WHO classification exhibited a higher discordance rate compared to any other classifications. Therefore, this result warrants further intensive consensus studies to improve the diagnostic reproducibility of PBLs with WHO classification.

Breast carcinomas of low malignant potential

Some breast carcinomas have a very low likelihood of metastasis to regional lymph nodes and distant sites and may be considered carcinomas of low malignant potential. In this article, we review the clinical, pathologic, immunophenotypic, and molecular features of selected breast carcinomas of low malignant potential including low-grade adenosquamous carcinoma, fibromatosis-like metaplastic carcinoma, encapsulated papillary carcinoma, solid papillary carcinoma, and tall cell carcinoma with reversed polarity.

Papillary lesions of the breast: A systematic evaluation of cytologic parameters

BACKGROUND

The cytologic diagnosis of papillary lesions of the breast is challenging because of the diverse morphology, including epithelial hyperplasia, atypia, low-grade malignancy, and neuroendocrine differentiation; also, traditional malignant features such as necrosis and myoepithelial cell loss can be lacking. Thus, the diagnostic criteria for papillary lesions may differ from those for other breast lesions. This study evaluated various cytologic parameters in a large cohort to identify useful diagnostic features.

METHODS

Cytologic preparations of papillary lesions with histologic follow-up were reviewed for features related to cellularity, epithelial cohesiveness, cellular and stromal architecture, cytomorphology, and background. Corresponding histologic slides were also reviewed.

RESULTS

In all, 153 cases were included. Epithelial discohesion, solid and cribriform patterns, atypical nuclear features, and mitoses (P ≤ .001 to P = .017) were associated with malignancy. Cell balls, monolayer sheets, and features of cystic change (P < .001 to P = .016) were associated with benign lesions. Complex (P = .031) and slender (P = .026) papillae and neuroendocrine features (P < .001) were associated with malignancy. Hemorrhage, background, and infiltrating neutrophils (P < .001 to P = .025) were associated with malignancy; fibrotic broad papillary stromal fragments (naked papillary fronds [NPFs]; P = .043) were associated with benignity. The presence of any single parameter, including the absence of myoepithelial cells within epithelial structure, the presence of cytoplasmic granules, an increased amount of cytoplasm, and a nuclear to cytoplasmic (N/C) ratio greater than 0.7, which were identified by principal component analysis, yielded a sensitivity of 95.1% and a specificity of 100.0% in predicting malignancy.

CONCLUSIONS

Methodological assessment of multiple features is recommended. Myoepithelial cells, cytoplasmic granules, the amount of cytoplasm, and the N/C ratio are key features for diagnosis.

Classical Lobular Carcinoma In Situ Arising From an Intraductal Papilloma of the Breast: A Case Report

Intraductal papilloma of the breast is a benign, mass-forming, proliferative lesion with a papillary architecture confined within a duct. Lobular neoplasia can rarely arise from an intraductal papilloma of the breast. In this article, we report the morphologic features of a rare case of classical LCIS (lobular carcinoma in situ) arising from an intraductal papilloma in a 76-year-old woman. The monomorphic dyscohesive cells were present between the myoepithelial and luminal epithelial layer in the periphery of the papilloma. These cells partially obliterated the spaces between the papillae forming solid sheets. The monomorphic dyscohesive cells showed lack of E-cadherin expression and uniform staining for estrogen receptor. We review the histologic differential diagnosis and stress the importance of correct classification to ensure optimal care for patients. We also propose a new criterion for the distinction of lobular neoplasia within a papilloma.

Papillary lesions of the breast: a review

Papillary breast lesions are rare breast tumors that comprise a broad spectrum of diseases. Pathologically they present as mass-like projections attached to the wall of the ducts, supported by fibrovascular stalks lined by epithelial cells. On mammogram they appear as masses that can be associated with microcalcifications. Ultrasound is the most used imaging modality. On ultrasound papillary lesions appear as homogeneous solid lesions or complex intracystic lesions. A nonparallel orientation, an echogenic halo or posterior acoustic enhancement associated with microcalcifications are highly suggestive of malignancy. MRI has proven to be useful to establish the extent of the lesion. Core needle biopsy is the gold standard for diagnosis. Surgical excision is usually recommended, although treatment for papillomas without atypia is still controversial.

Pathology of breast papillary neoplasms: Community hospital experience

In this study, 550 breast papillary neoplasms collected in a community hospital over more than ten years were reviewed and analyzed. This included 457 intraductal papillomas, 53 papillary carcinomas, 35 papillary DCIS and five invasive papillary carcinomas. The diagnostic rate of papillary neoplasms increased over time, likely due to better recognition by pathologists. Intraductal papillomas occurred most frequently in the upper outer quadrants and contained ADH/DCIS in 19% of cases. A total of 28% of non-incidental papillomas were associated with ADH/DCIS, and 29% of patients with papillomas had ADH/DCIS in adjacent tissue; nearly half of papillomas that were > 1 cm in size contained ADH/DCIS in the papilloma or adjacent to it. No single feature could predict an upgrade on excision for non-atypical intraductal papillomas diagnosed on core biopsy. There was no significant difference in the association of ADH/DCIS with central or peripheral papillomas. The overall upgrade rate of non-atypical intraductal papillomas to DCIS on excision was 2%, which justifies the conservative management of non-atypical sub-centimeter lesions. Papillary carcinomas occurred in older than intraductal papilloma patients and were most frequent in the upper quadrants. Although classically devoid of a myoepithelial cell layer, papillary carcinomas may contain some residual or even an ample myoepithelial cell layer in the papillae. An association between papillary carcinoma and conventional invasive carcinoma was found in 40% of EPCs and 89% of SPCs. Papillary DCIS was usually low- or intermediate-grade. The presence of a myoepithelial cell layer in the papillae was not inconsistent with this diagnosis. Invasive papillary carcinoma may have two histologic patterns: papillary and cribriform.

Encapsulated papillary carcinoma of breast; a clinicopathological study of 25 cases and literature review with emphasis on high grade variant

Encapsulated Papillary Carcinoma (EPC) is a rare breast tumor with excellent prognosis. Treatment and stage of EPC is influenced by invasion and high nuclear grade. Our aim was to study the clinicopathological features of EPC, especially high grade tumors and to compare the features of invasive and non-invasive tumors. We reviewed clinicopathological features of 25 cases of EPC diagnosed at our institution from 2006 till 2020. Patients' age ranged from 21 to 75 years (median 55 years). Tumor size ranged from 1 to 9 cm (median 3.5 cm). Overall, invasion was present in 44% cases. High nuclear grade was observed in 24% cases. Majority of these high grade tumors were below 40 years. All of these tumors were 4 cm or larger in size. Two third of these tumors were invasive. Hormone receptor negativity and lymph node involvement was observed in 1 out of 3 cases, when performed. Clinicopathological and histological features of invasive and non-invasive tumors were compared and only lymph node involvement was found to be significantly more frequent in invasive tumors (p = 0.049). Median follow up duration was 18 months. All patients were alive and disease free except for a single patient who died of cerebrovascular accident. EPC has excellent clinical course. Invasion and high nuclear grade should be carefully searched for as these features determine tumor stage and treatment.

Invasive solid papillary carcinoma with neuroendocrine differentiation of the breast: a case report and literature review

Background

Solid papillary carcinoma (SPC) of the breast is a rare breast cancer that accounts for less than 1% of all breast cancers. The optimal clinical management of SPC remains controversial. Here, we report a case of invasive SPC with neuroendocrine differentiation in addition to review of the current literature.

Case presentation

A premenopausal 46-year-old female presented with a mass in her left breast that tended to increase in size over a 10-month period. Mammography and ultrasonography revealed a mass in the left upper-inner quadrant. The resulting images suggested a category 3 breast tumor according to the Breast Imaging Reporting and Data System (BI-RADS). A core needle biopsy (CNB) was performed, and the pathological findings showed a solid papillary pattern and atypical cells suggestive of noninvasive SPC. After a left partial mastectomy and sentinel lymph node biopsy (SLNB), the specimens were sent for histopathological analysis for further investigation. Postoperative pathological findings suggested invasive SPC. Whole-breast radiation therapy and adjuvant hormonal therapy were performed as postoperative treatments. Three years after surgery, multiple lung metastases were detected, and the patient was treated with a gonadotropin-releasing hormone agonist and an aromatase inhibitor. Five months later, multiple liver metastases and bone metastases appeared, and oral 5-fluorouracil was chosen for the subsequent treatment. The patient has been treated for 5 years to date, and she is continuing to take oral 5-fluorouracil and is alive without any further disease progression.

Conclusions

We report a rare case of premenopausal invasive SPC with multiple metastases. Further study is needed to clarify the molecular characteristics and clinical behaviors of SPC and to explore the optimal treatment strategy.

Intraductal sebaceous papilloma of a meibomian gland: a new entity possibly associated with the MSH6 subtype of the Muir-Torre syndrome

Over several months, a painless, multinodular, non-erythematous swelling of the deep tissues of his left upper eyelid developed in a 63-year-old man. An excisional biopsy with histopathologic evaluation disclosed a unique sebaceous papilloma within a cyst lined by non-keratinizing squamous epithelium that focally displayed a variably thick, superficial, eosinophilic cuticular layer. Immunohistochemical staining demonstrated that the tumor and its epithelial cystic lining had a profile consistent with Meibomian gland duct epithelium. Adipophilin highlighted cytoplasmic vacuolar lipid positivity. The encapsulation of the lesion, absence of nuclear atypia, and Ki-67 nuclear positivity restricted to the basilar cells established its intrinsically benign nature. The patient's clinical history was remarkable for pulmonary and colonic carcinomas resected, respectively, 20 years and 8 years earlier. DNA mismatch repair protein expression studies disclosed loss of nuclear immunostaining of MSH6 protein, pointing to the possibility of an underlying rare MSH6 variant of the Muir-Torre syndrome, not yet described in the ophthalmic literature. p16 nuclear positivity was also found in the tumor cells, indicating the possible role of high-risk human papillomavirus as an additional factor in the genesis of the tumor. Genetic evaluation of normal and tumoral tissues in future similar cases will detect if there is an underlying germline mutation versus a somatic mutation limited to the tumor. This will be required to fully establish a predictable linkage with this new subtype of the Muir-Torre syndrome.

A papilloma in a large cyst of the breast: A case report

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Intracystic lesions of the breast prove to be benign more often than malignancy.

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Most intracystic lesions are benign papillomas.

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Generally sizes of cysts that contain papilloma are small. Relatively cysts that contain papillary carcinoma are large.

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We present a 53-year-old with a papilloma in a large cyst of the breast that presented a painless palpable mass.

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Excisional biopsy may be needed to make a proper diagnosis for the suspicious lesion.

Introduction

Intracystic lesions of the breast prove to be benign more often than malignancy, most intracystic lesions are benign papillomas. Generally sizes of cysts that contain papilloma are small. Relatively cysts that contain papillary carcinoma are large. A papilloma in a large cyst of the Breast is rare.

Presentation of case

We report a rare case of a papilloma in a large cyst of the breast that presented a painless palpable mass. A 53-yr-old woman noticed palpable mass in her right breast. Ultrasonography indicated a 7 × 7 cm sized large cyst. There is a 2 × 2.5 cm sized hyper-echoic, polypoid mass in the cyst. On fine-needle aspiration was not obtained malignant cells. Excisional biopsy was done. Pathologic finding was papilloma.

Discussion

Tumors in a large cyst of the breast is difficult in distinguish benign from malignancy by preoperative imaging, cytological and histological study.

Conclusion

Excisional biopsy should be performed before cancer surgery such as mastectomy to manage the cysts with intracystic growths.

Magnetic resonance imaging features for differentiating breast papilloma with high-risk or malignant lesions from benign papilloma: a retrospective study on 158 patients

Background

Benign breast papilloma is currently managed with conservative management with close observation. In contrast, papilloma with high-risk or malignant lesions warrants surgical excision. The purpose of our study was to investigate magnetic resonance imaging (MRI) features of breast papilloma and to identify imaging diagnostic indicators for papilloma with high-risk or malignant lesions.

Methods

MRI features of 175 surgically confirmed papillomas on 158 patients were retrospectively reviewed. The 175 cases included 132 cases of benign papilloma and 43 cases of papilloma with high-risk or malignant lesions. The MRI features of these lesions were classified into three types: mass, non-mass enhancement (NME), and occult lesion. The occult lesion was defined as the presence of only ductal dilation without any enhanced lesions on MRI. For a mass lesion, the mixed mass-NME lesion was considered if linear, segmental or regional enhanced lesion was found adjacent to the mass. Clinical and MRI features were compared by univariate and multivariate analysis between the benign papilloma and the papilloma with high-risk or malignant lesions.

Results

Multivariate logistic regression analysis demonstrated that clinical characteristics including being or older than 50 years (odds ratio [OR] = 4.506), having bloody nipple discharge (OR = 4.499), and concurrent breast cancer (OR = 5.083) were significant indicators for papilloma with high-risk or malignant lesions. On MRI, most papillomas presented as mass (n = 135, 77.1%), and fewer as NME (n = 37, 21.1%) and occult lesion (n = 3, 1.7%). For the mass lesion, the logistic regression analysis demonstrated that a mass size exceeding 10 mm (OR = 2.956) and mixed mass-NME lesion (OR = 4.143) were independent risk indicators for a papilloma with high-risk or malignant lesions. For the NME lesion, the segmental or regional distribution was more commonly observed in the papilloma with high-risk or malignant lesions (61.5%) than the benign papilloma (12.5%) (P = 0.006). All the cases of occult lesions were benign papillomas.

Conclusions

MRI features including a mass size exceeding 10 mm, mixed mass-NME lesion, and NMEs with segmental or regional distribution indicate a papilloma with high-risk or malignant lesions.

A case of giant complicated intraductal papilloma of breast on MRI and literature review

BACKGROUND

With the increasing use of image-guided biopsy, more breast intraductal papillomas are found than ever. Most intraductal papillomas are small, ranging from several milimeters to 2 cm.

CASE

We described a case of giant intraductal papilloma of breast in a 19-year-old girl with nipple bloody discharge and rapid growth. Magnetic resonance imaging diagnostic evaluation and pathologic correlation along with review of relevant literatures are documented. The lesion was characterized by presence of mixture of cystic and solid component with cystic component occupying a large space. The solid component showed morphologic, kinetic, and diffusion weighted imaging features suggestive of malignancy. Infarction with no enhancement was noted. Cystic compartments contained hemorrhage with fluid-fluid level formation. The patient undertook lumpectomy.

CONCLUSION

For a giant breast tumor with mixed solid and cystic component, intraductal papilloma should be considered in the differential diagnosis.

Subclonal analysis in a lobular breast cancer with classical and solid growth pattern mimicking a solid-papillary carcinoma

Recently, a new variant of invasive lobular breast cancer (ILBC) with solid-papillary-like growth pattern has been described. We present a case of ILBC with solid-papillary-like growth pattern in the main tumour mass and classical invasive lobular growth pattern in adjacent satellite foci. The two tumour components were subjected to comprehensive molecular analyses. Both components were ER/PR-positive, HER2-negative, and showed a complete loss of E-cadherin and beta-catenin protein expression, as determined by immunohistochemistry. Gene expression profiling classified the main tumour and a satellite focus as luminal-B and luminal-A subtypes, respectively. Whole-genome copy number profiles were highly similar in both tumour components. Shared copy number alterations (CNAs) included gains of chromosome 1q21.1-q43 and losses of chromosome 16q11.2-q24.3, the locus of the CDH1/E-cadherin tumour suppressor gene. CNAs detected only in the main tumour included a gain of chromosome 20q12-q13.33 and a loss of chromosome 1p36.33-p34.3, which has recently been associated with the solid variant of ILBC. Next generation sequencing revealed an identical, truncating CDH1 mutation (p.G169fs*5) in both tumour components confirming a common clonal ancestry. In conclusion, we confirm the recently described variant of ILBC with solid-papillary-like growth pattern and provide evidence that it evolves from classical ILBC by subclonal evolution.