[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-358195-105":59,"doc-detail-358195-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","primary-neuroendocrine-carcinoma-of-the-breast-a-diagnostic-challenge-and-case-report","Primary Neuroendocrine Carcinoma of the Breast - A Diagnostic Challenge and Case Report","","Primary neuroendocrine carcinoma of the breast (NECB) is an exceedingly rare malignancy, reported at under 0.5% of all breast carcinomas and around 1% of neuroendocrine neoplasms. A 61-year-old postmenopausal woman presented with a palpable left breast mass; initial core biopsy suggested infiltrative ductal carcinoma, while subsequent comprehensive histopathology confirmed NECB via diffuse neuroendocrine marker positivity. Multimodal treatment combined surgery, adjuvant chemotherapy, radiation, and endocrine therapy. The case emphasizes frequent diagnostic discordance and the need for thorough immunohistochemistry, as established optimal treatment strategies remain incompletely defined.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":35,"@type":76,"position":81},"https://docshare.wps.com/document/healthcare/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/primary-neuroendocrine-carcinoma-of-the-breast-a-diagnostic-challenge-and-case-report/358195/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/primary-neuroendocrine-carcinoma-of-the-breast-a-diagnostic-challenge-and-case-report/358195.png","ImageObject",300,407,{"name":92,"@type":93},"MrHarris58","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-30","2026-09-23",true,{"@type":102,"interactionType":103,"userInteractionCount":44},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"What makes primary neuroendocrine carcinoma of the breast (NECB) difficult to diagnose?","Question",{"text":112,"@type":113},"NECB frequently mimics conventional breast carcinoma on initial assessment. Discordance between core biopsy and final pathology highlights the need for comprehensive immunohistochemical evaluation in morphologically suggestive cases.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"How was the diagnosis confirmed in the presented case?",{"text":117,"@type":113},"After modified radical mastectomy, comprehensive histopathology showed neuroendocrine morphology with diffuse positivity for synaptophysin and chromogranin A, confirming primary neuroendocrine carcinoma of the breast, grade 2 (T2N0M0).",{"name":119,"@type":110,"acceptedAnswer":120},"What treatments were used for the patient?",{"text":121,"@type":113},"Management combined modified radical mastectomy with sentinel lymph node biopsy (all nodes negative), adjuvant anthracycline-taxane chemotherapy, chest wall radiation (50 Gy in 25 fractions), and endocrine therapy with anastrozole.","https://schema.org",{"og:url":83,"og:type":124,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":126,"canonical":83},"index,follow",{"doc_id":128,"site_id":62},358195,1790650527,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":34,"category_name":35,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":44,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":52,"language":139,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":67,"update_tm":143,"read_time":144},687212988360,"https://ap-avatar.wpscdn.com/davatar_276721f389ce27ea32af1340a28f341c","Cancer Reports   \n CASE REPORT  OPEN ACCESS   \nPrimary Neuroendocrine Carcinoma of the Breast: A Diagnostic Challenge and Case Report  \nHamid Zeinali Nezhad1  | Shima Yaghoobi2  | Nazanin Zeinali Nezhad2  | Amirhossein Shahpar3  | Abtin Malekpour Afshar4  | Mina Bagherijamebozorgi5   \n1Kerman University of Medical Sciences, Kerman, Iran | 2Physiology Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran | 3Gastroenterology and Hepatology Research Center, Institute of Basic and Clinical Physiology Sciences, Kerman, Iran | 4Clinical Research Development Unit, Afzalipour Hospital, Kerman University of Medical Sciences, Kerman, Iran | 5Pathology and Stem Cell Research Center, Department of Pathology, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran  \nCorrespondence: Nazanin Zeinali Nezhad ([nazaninzeinali4@gmail.com](nazaninzeinali4@gmail.com))  \nReceived: 27 July 2025 | Revised: 19 February 2026 | Accepted: 2 March 2026  \nKeywords: breast carcinoma | diagnostic challenges | immunohistochemistry | misdiagnosis | multimodal therapy | primary neuroendocrine carcinoma  \nABSTRACT  \nBackground: Primary neuroendocrine carcinoma of the breast (NECB) represents an exceedingly rare entity, comprising less than 0.5% of all breast carcinomas and approximately 1% of all neuroendocrine neoplasms. The 2019 WHO classification defines NECB as tumors expressing neuroendocrine markers in > 90% of tumor cells with morphological features resembling neuroendocrine tumors of other anatomical sites.  \nCase Presentation: A 61-year-old postmenopausal female presented with a palpable left breast mass. Clinical examination revealed a 2 × 3 cm firm, poorly circumscribed mass at the 9 o'clock position with multiple satellite lesions and a solitary axillary lymph node measuring 1.5 × 1.5 cm with rubbery consistency. Sonographic evaluation demonstrated a hypoechoic mass with spiculated margins, heterogeneous echotexture, and posterior acoustic shadowing, classified as BI-RADS 6. Core needle biopsy yielded an initial diagnosis of infiltrative ductal carcinoma, grade III, with immunohistochemistry demonstrating ER+/PR+/ HER2-status and a Ki-67 index of 22% . Following modified radical mastectomy, comprehensive histopathological examination revealed distinctive neuroendocrine morphology with diffuse positivity for synaptophysin and chromogranin A, confirming the diagnosis of primary neuroendocrine carcinoma of the breast, grade 2, T2N0M0 . The patient underwent multimodal therapy comprising modified radical mastectomy with sentinel lymph node biopsy (all 17 nodes negative), adjuvant anthracycline-taxane chemotherapy, chest wall radiation (50 Gy in 25 fractions), and endocrine therapy with anastrozole.  \nConclusion: This case highlights the diagnostic challenges of NECB, which frequently mimics conventional breast carcinoma on initial assessment. The diagnostic discordance between core biopsy and final pathology underscores the imperative for comprehensive immunohistochemical evaluation in morphologically suggestive cases. Management strategies integrate established breast cancer protocols with neuroendocrine-specific considerations, though optimal treatment paradigms remain incompletely defined due to the paucity of dedicated clinical trials for this rare entity.  \n1 | Introduction  \nPrimary neuroendocrine carcinoma of the breast (NECB) represents an uncommon and distinctive neoplasm, characterized by morphological patterns similar to those of neuroendocrine  \ntumors occurring in other anatomical sites, while exhibiting histopathological features of mammary carcinoma [1] . Initially described by Feyrter and Hartmann in 1963, NECB was formally recognized as a distinct entity in 2003 by the World Health Organization (WHO) [2, 3] . The 2019 WHO  \nThis is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium","cbCaikPmPhlXaCFp","https://ap.wps.com/l/cbCaikPmPhlXaCFp","pdf",1227989,"English","# Abstract\n# Introduction\n## Background and definition\n## Epidemiology and diagnostic challenges\n## Etiopathogenesis and molecular findings\n## Prognosis and clinical behavior","[{\"question\":\"What makes primary neuroendocrine carcinoma of the breast (NECB) difficult to diagnose?\",\"answer\":\"NECB frequently mimics conventional breast carcinoma on initial assessment. Discordance between core biopsy and final pathology highlights the need for comprehensive immunohistochemical evaluation in morphologically suggestive cases.\"},{\"question\":\"How was the diagnosis confirmed in the presented case?\",\"answer\":\"After modified radical mastectomy, comprehensive histopathology showed neuroendocrine morphology with diffuse positivity for synaptophysin and chromogranin A, confirming primary neuroendocrine carcinoma of the breast, grade 2 (T2N0M0).\"},{\"question\":\"What treatments were used for the patient?\",\"answer\":\"Management combined modified radical mastectomy with sentinel lymph node biopsy (all nodes negative), adjuvant anthracycline-taxane chemotherapy, chest wall radiation (50 Gy in 25 fractions), and endocrine therapy with anastrozole.\"}]","Primary Neuroendocrine Carcinoma of the Breast - A Diagnostic Challenge and Case Report | PDF",1790133162,25]