Neuroendocrine ductal carcinomain situ(NE-DCIS) of the breast - comparative clinicopathological study of 20 NE-DCIS cases and 274 non-NE-DCIS cases

INSM1 immunostaining in solid papillary carcinoma of the breast

Solid papillary carcinoma (SPC) is a histological subtype of breast carcinomas. At least 50% of SPC show neuroendocrine differentiation. Insulinoma-associated protein 1 (INSM1) is a transcription factor now employed as a useful neuroendocrine marker. It is suppressed by the Notch signaling pathway in other neuroendocrine tumors. However, the usefulness of INSM1 as a neuroendocrine marker and the relationships between INSM1 and NOTCH receptors in SPC of the breast currently remain unclear. To clarify the usefulness of INSM1 as a neuroendocrine marker and the relationships between INSM1 and NOTCH receptors in SPC, we performed immunohistochemistry using 19 tissue specimens of SPC of the breast. We complementarily analyzed public RNA sequencing data on breast carcinomas. Immunohistochemical examinations revealed that the staining intensity of INSM1 was significantly higher in the neuroendocrine group than in the non-neuroendocrine group. Positive correlations were observed between INSM1 and synaptophysin (SYP), or chromogranin-A (CHGA). In all cases, NOTCH 2 and 3 were positive, while NOTCH 1 and 4 were negative. According to public RNA data analyses, there were positive correlations between INSM1 and SYP, or CHGA, and negative correlations between INSM1 and NOTCH1-3. INSM1 is useful as a diagnostic marker for SPC with neuroendocrine differentiation in the breast.

The rare entity of bilateral and unilateral neuroendocrine metastases to the breast: a case series and literature review

Introduction

Primary neuroendocrine neoplasms (NENs) in the breast are very rare. Until 2011, the prevalence was 0.1% of all breast lesions and 1% of all NENs, whereas metastatic breast NENs represent 1%–2% of all breast tumours. However, it seems that over the last 5 years the diagnostic frequency of breast NENs has increased, probably for more alert specialists and advanced diagnostic tools, leading to a prevalence of 2%–5% of diagnosed breast cancers, mostly in the elderly population. Breast metastases from extramammary malignancies are uncommon and bilateral ones are even more uncommon, with few reported in the literature. We describe four clinical settings of breast metastases from different NENs and the multidisciplinary approach for diagnosis and treatment.

Methods

Four patients were found to have NEN primaries metastasised to the breast. A literature review was conducted to identify similar cases and characterise breast metastases from neuroendocrinal tumors (NETs).

Results

Two patients presented with bilateral breast metastases (one with well-differentiated panNET and another with atypical lung carcinoid) and two had unilateral (one with moderately differentiated lung NET and one with atypical lung carcinoid). There are about 13 cases of NEN breast metastases reported in the English literature. The ileum is the most common primary site, followed by the appendix, duodenum, pancreas and lung.

Conclusion

Breast lesions from extramammary primary often pose a diagnostic challenge, since a breast nodule can be the first and often the only presentation of the disease. However, differentiating between primary and secondary NEN breast lesions is essential, owing to different clinical management and prognosis.

Histopathological and Clinical Differences Between Primary Breast Carcinomas With Neuroendocrine Features and Primary Breast Carcinomas Mimicking Neuroendocrine Features

We aimed to determine the histopathological differences between primary breast carcinomas with neuroendocrine features (NEBC) and carcinomas mimicking neuroendocrine features (NEBC-like). Twenty-three cases with NEBC, all showing positive staining for synaptophysin and/or chromogranin-A in ≥50% of tumor cells and 36 cases with NEBC-like (no staining for neuroendocrine [NE] markers but suspicious for NE morphology in terms of solid/trabecular growth patterns) were included in the study. Significant differences were found between the groups in terms of the patients' ages, histologic/nuclear grade of tumor, lymphovascular invasion, comedo-type ductal carcinoma in situ (DCIS), microcalcification, Ki-67 proliferation index, nuclear shape, and level of peritumoral lymphocytic infiltration. The presence of large-size solid cohesive groups of tumor cells; plasmocytoid, spindle, and/or columnar shapes of tumor cells; and eosinophilic-granular appearance of cytoplasm were mostly noted in the NEBC group. The presence of small- to medium-sized solid cohesive groups of tumor cells; high-grade histologic and nuclear features; clear cytoplasm; and round to ovoid nucleus were mostly noted in the NEBC-like group. No significant differences were found in terms of tumor size, ER/PR/HER2 status, as well as the presence of DCIS, elastosis, extracellular/intracellular mucin, signet ring cells, apocrine features, and accompanying papilloma or ductal ectasia. In conclusion, small- to medium-sized solid cohesive groups of tumor cells, high-grade features, clear cytoplasm, round to ovoid shape of nucleus, lymphovascular invasion, comedo-type DCIS, microcalcification, high level of Ki-67 proliferation index (≥20%), and moderate/strong level of peritumoral lymphocytic infiltration might support non-NE features in breast carcinomas.

Use of immunohistochemical analysis of CK5/6, CK14, and CK34betaE12 in the differential diagnosis of solid papillary carcinoma in situ from intraductal papilloma with usual ductal hyperplasia of the breast

Objectives:

The aim of this study was to use immunohistochemistry to differentiate solid papillary carcinoma in situ from intraductal papilloma with usual ductal hyperplasia (IPUDH). Three types of high-molecular-weight cytokeratins (CKs) – CK5/6, CK14, and CK34betaE12 – were targeted.

Methods:

We studied 17 patients with solid papillary carcinoma in situ and 18 patients with IPUDH diagnosed by at least two pathologists. Immunohistochemical analyses used antibodies to CK5/6, CK14, and CK34betaE12 to make the differential diagnosis of solid papillary carcinoma in situ versus IPUDH. Immunohistochemical staining was scored as 0–5 using Allred score.

Results:

Immunohistochemistry with CK5/6 and CK14 antibodies produced scores of 0–3 in all patients with solid papillary carcinoma in situ and 2–5 in all patients with IPUDH. Immunohistochemical staining with CK34betaE12 antibody produced scores of 1–3 in all patients with solid papillary carcinoma and 3–5 in all patients with IPUDH. In tissues from patients with IPUDH, significantly more cells were stained with CK34betaE12 than CK5/6 (p < 0.05) or CK14 (p < 0.05).

Conclusion:

The immunoreactivity of CK5/6, CK14, and CK34betaE12 antibodies was useful to differentiate solid papillary carcinoma in situ from IPUDH. CK34betaE12 is especially useful for distinguishing solid papillary carcinoma from IPUDH.

Triple receptor-positive primary neuroendocrine carcinoma of breast in a young patient

Primary neuroendocrine carcinoma of breast is a very rare malignancy and preoperative diagnosis is difficult by clinical examination alone.Most oftenly, histopathological examination (HPE) and immunohistochemistry (IHC) studies are required to establish the diagnosis. We describe here a case of a primary neuroendocrine carcinoma of right breast in a 32-year-old woman. The patient underwent a right modified radical mastectomy, and the diagnosis was conclusively established postoperatively by the HPE and IHC reports. The IHC report revealed positive status of oestrogen, progesterone and Herceptin receptors.

Neuroendocrine Differentiation in Breast Cancer: Clinicopathological Significance of Bcl-2 Positive Solid Papillary Carcinoma

Solid papillary carcinoma (SPC) is considered a rare malignant breast tumor. Maluf and Koerner first reported this disease entity as a special type of ductal carcinoma in situ with several characteristic histopathological features, including low-grade cellular atypia, intracellular or extracellular mucin deposition, and solid papillary growth pattern, as well as neuroendocrine differentiation. The present paper describes a case of SPC with bcl-2 expression, which is known as a marker for malignancy of neuroendocrine tumors. Interestingly, despite bcl-2 expression being a poor prognostic indicator of neuroendocrine tumors, the patient with this tumor has achieved long-term survival (approximately 6 years) at the time of writing this report. Because previous investigators reported that bcl-2 expression might play a role in the inhibition of the development of breast cancer, we suggest that bcl-2 expression might reflect a good prognosis in patients with SPC, rather than being a poor prognostic indicator, as it is in several types of neuroendocrine tumor. However, to confirm this hypothesis, further investigation is required.

Pathological examination of breast cancer biomarkers: current status in Japan

This article reviews the current status of pathological evaluation for biomarkers in Japan. The introduced issues are the international trends for estimation of biomarkers considering diagnosis and treatment decision, and pathological issues under discussion, and how Japanese Breast Cancer Society (JBCS) members have addressed issues related to pathology and biomarkers evaluation. As topics of immunohistochemical study, (1) ASCO/CAP guidelines, (2) Ki67 and other markers, (3) quantification and image analysis, (4) application of cytologic samples, (5) pre-analytical process, and (6) Japan Pathology Quality Assurance System are introduced. Various phases of concepts, guidelines, and methodologies are co-existed in today's clinical practice. It is expected in near future that conventional methods and molecular procedures will be emerged, and Japanese Quality assurance/Quality control (QA/QC) system will work practically. What we have to do in the next generation are to validate novel procedures, to evaluate the relationship between traditional concepts and newly proposed ideas, to establish a well organized QA/QC system, and to standardize pre-analytical process that are the basis of all procedures using pathological tissues.

Neuroendocrine breast carcinoma metastatic to the liver: Report of a case and review of the literature

INTRODUCTION

Primary neuroendocrine breast carcinoma (NEBC) is a rare entity of breast cancer.

PRESENTATION OF CASE

We herein report a case of right hepatectomy for a NEBC liver metastasis.

DISCUSSION

Little is known about its evolution, bilologic behavior and optimal treatment. Its malignant potential has been addressed in few reports, with cases of metachronous metastases in diverse sites, even years following treatment of the breast primarily.

CONCLUSION

Treating this kind of cancer implies both breast and hepatic surgery.

Primary neuroendocrine breast carcinoma (NEBC) is a rare entity of breast cancer. Little is known about its evolution, biologic behavior and optimal treatment. Its malignant potential has been addressed in few reports, with cases of metachronous metastases in diverse sites, even years following treatment of the breast primarily. We herein report a case of right hepatectomy for a NEBC liver metastasis.

Metastases from neuroendocrine tumors to the breast are more common than previously thought. A diagnostic pitfall?

BACKGROUND

Metastases from neuroendocrine tumors (NETs) to the breast have been described as a rare phenomenon. Presentation, imaging results, and cytopathologic findings of these tumours may closely mimic those of a mammary carcinoma.

METHODS

This study was a retrospective review of 661 patients with metastatic NETs, of whom 280 were females, treated at Uppsala University Hospital, Uppsala, Sweden. Patients with pathological breast lesions were identified. Histopathological slides from available NET breast lesions were analyzed for mammary carcinoma and neuroendocrine markers.

RESULTS

We have identified 20 female patients with NET metastases to the breast, 11/235 with small intestinal NETs, 8/55 with lung NETs, and 1/6 with thymic NETs. There were no male patients with NET metastatic to the breast. Four patients had their breast lesion initially diagnosed as mammary carcinoma. Retrospectively, these lesions showed negative staining for mammary carcinoma markers.

CONCLUSIONS

Metastases to the breast from neuroendocrine tumors may be more common than previously thought. Patients with a lesion to the breast and symptoms typical for NET may benefit from additional histopathological investigation, because NET metastases and mammary carcinoma have different immunohistochemical profiles.

Locally-advanced primary neuroendocrine carcinoma of the breast: case report and review of the literature

Background

Primary neuroendocrine carcinoma of the breast is a heterogeneous group of rare tumors with positive immunoreactivity to neuroendocrine markers in at least 50% of cells. Diagnosis also requires that other primary sites be ruled out and that the same tumor show histological evidence of a breast in situ component. Primary neuroendocrine carcinoma of the breast rarely presents as locally advanced disease and less frequently with such widespread metastatic disease as described herein. The review accompanying this case report is the first to provide an overview of all the cases of primary neuroendocrine carcinoma of the breast published in the literature and encompasses detailed information regarding epidemiology, histogenesis, clinical and histologic diagnosis criteria, classification, surgical and adjuvant treatment, as well as prognosis. We also provide recommendations for common clinical and histologic pitfalls associated with this tumor.

Case presentation

We describe a case of a 51-year-old Hispanic woman initially diagnosed with locally-advanced invasive ductal carcinoma that did not respond to neodjuvant treatment. After undergoing modified radical mastectomy the final surgical pathology showed evidence of alveolar-type primary neuroendocrine carcinoma of the breast. The patient was treated with cisplatin/etoposide followed by paclitaxel/carboplatinum. Thirteen months after surgery the patient is alive, but developed pulmonary, bone, and hepatic metastasis.

Conclusion

The breast in situ component of primary neuroendocrine carcinoma of the breast may prevail on a core biopsy samples increasing the probability of underdiagnosing this tumor preoperatively. Being aware of the existence of this disease allows for timely diagnosis and management. Optimal treatment requires simultaneous consideration of both the neuroendocrine and breast in situ tumor features.

High prevalence of neuroendocrine carcinoma in breast lesions detected by the clinical symptom of bloody nipple discharge

AIM

Bloody nipple discharge (BND) is an important clinical symptom in breast disorders, especially cancers. However, the association between this symptom and breast neuroendocrine carcinomas (NECs) has not been sufficiently investigated or well understood.

METHODS

We clinicopathologically studied 89 cases using biopsy and/or resection in 144 patients who came to the hospital for a thorough examination of symptomatic BND.

RESULTS

Of these 89 cases examined histologically, 24 (27%) were neuroendocrine carcinomas (NECs) in which >50% of cells immuno-expressed chromogranin A and/or synaptophysin. Moreover, NECs made up 44% (24/55) of the mammary cancers found because of the BND. The frequency of diagnosing malignancy preoperatively in 24 NECs was 4% by nipple discharge cytology, 40% by fine needle aspiration cytology, 62% by core needle biopsy and 67% by mammotome biopsy. There were neither postoperative recurrences nor metastases in the NEC cases during a mean follow-up of 83.7 months. The 24 NECs were subclassified into neuroendocrine ductal carcinoma in situ (NE-DCIS) (9 cases) and microinvasive (7 cases) and invasive (8 cases) NECs with extensive NE-DCIS components. Most NECs had early-stage and low-grade pathological parameters: pTis or pT1 (96%), pN0 (96%), low nuclear grade (83%), absence of necrosis (88%), immuno-positivity of estrogen and progesterone receptors (100%) and absence of HER2 protein overexpression (100%).

CONCLUSIONS

NECs predominantly with NE-DCIS lesions, often under-diagnosed preoperatively, accounted for an important share of breast conditions associated with BND. It is, therefore, worth keeping this type of breast cancer in mind when performing medical examinations on patients with BND.

Double neuroendocrine ductal carcinomas in situ coexisting with a background of diffuse idiopathic neuroendocrine cell hyperplasia of breast: a case report and hypothesis of neuroendocrine tumor development

This article reports the case of a 72-year-old woman with two nodules of neuroendocrine (NE) ductal carcinoma in situ coexistent with a background of NE cell hyperplasia. Both tumors, 15 and 3 mm in size, were incidentally revealed on computed tomography without any apparent clinical symptoms. The tumors showed similar histological features, and more than 50% of the tumor cells patchily expressed NE markers, such as chromogranin A, synaptophysin, CD56, and somatostatin receptor type 2. The surrounding nontumor ductal cells also showed spotty or linear positivity for NE markers in contrast to the cells of normal atrophic breasts, which rarely present with NE cells. Moreover, focal mucin production was also observed in the peripheral ducts. It is hypothesized that idiopathic breast NE cell hyperplasia with multiple small nests of NE cells may extend to form a true mass of NE neoplasms.

Synchronous bilateral neuroendocrine ductal carcinoma in situ

Neuroendocrine ductal carcinoma in situ (NE-DCIS) is a breast malignancy that has characteristic clinicopathological features and can, therefore, be regarded as a distinct variant of DCIS. The patient was a 54-year-old premenopausal woman with hemorrhagic nipple discharge in her left breast. Magnetic resonance imaging and ultrasound (US) images of the left breast showed mass-like lesions, while concurrent images of the right breast showed non-mass-like lesions. These findings suggested the presence of both benign and malignant tumors. Pathological findings from US-guided core-needle biopsy of the left mass were highly suspicious of a malignant tumor. Excisional biopsy of both breasts was performed. We could define the diagnosis of breast cancer by the second opinion on pathological diagnosis. The tumor cells showed histological characteristics of NE-DCIS. Bilateral breast lesions had histopathological similarities and were composed of predominantly solid growth of carcinoma cells, frequently with well-developed vascular structures, in mammary ducts and ductules. Carcinoma cells were polygonal or occasionally spindle shaped and had fine-granular, relatively eosinophilic cytoplasm. The nuclei of these cells showed round to ovoid in shape and fine-granular chromatin pattern. There was not any invasive component, as confirmed by careful histological examination. Thus, additional immunohistochemical stainings for NE markers (chromogranin A and synaptophysin) were performed. Staining statuses of these markers were positive in almost all tumor cells from both breasts. Both tumors were therefore diagnosed as NE-DCIS. To our knowledge, this case is the first report of NE-DCIS diagnosed synchronously in both breasts.

Neuroendocrine differentiation in breast cancer: established facts and unresolved problems

Neuroendocrine breast carcinoma (NEBC) diagnosis relies on (i) presence of morphologic neuroendocrine features, and (ii) neuroendocrine markers expressed in more than 50% of tumor cells. The World Health Organization classification describes 3 main histologic types: the solid, the small/oat cell, and the large cell variant. In addition, we have recently proposed a further categorization into 5 subgroups: the first 3 categories encompass solid lesions and include (i) solid cohesive carcinomas, (ii) alveolar carcinomas, and (iii) small cell carcinoma; the last subgroups include mucin-producing tumors which are (iv) solid papillary carcinomas and (v) cellular mucinous carcinomas. Chromogranin A and synaptophysin have been considered as the most sensitive and specific neuroendocrine markers in NEBC. At the molecular level, recent gene expression profiling studies have shown that NEBCs pertain to the luminal molecular type, being positive for hormone receptors and negative for HER2. Moreover, it has been demonstrated that mucinous and neuroendocrine carcinomas are transcriptionally distinct from conventional invasive ductal carcinomas. Following the above criteria, NEBCs constitute approximately 1% of all breast carcinomas. The clinical effect of neuroendocrine breast cancer is still a matter of debate; however, when compared with unselected breast cancers, NEBCs show a less aggressive clinical behavior.