[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-349210-105":59,"doc-detail-349210-en":131},{"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":124,"head_meta":126,"extra_data":128,"updated_unix":130},105,"en","thyroid-collision-carcinoma-a-case-report","Thyroid Collision Carcinoma - A Case Report","","Thyroid collision tumor refers to the rare synchronous coexistence of papillary thyroid carcinoma (PTC) and medullary thyroid carcinoma (MTC), creating distinctive diagnostic difficulties. This case report describes a 61-year-old woman with a painless anterior neck mass and voice hoarseness, previously treated for benign multinodular goiter. Fine-needle aspiration suggested metastatic carcinoma, likely MTC. Surgical completion total thyroidectomy and histopathology revealed PTC in the right lobe and concurrent MTC in central lymph nodes, with no recurrence on follow-up.",{"@graph":69,"@context":123},[70,84,106],{"@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/thyroid-collision-carcinoma-a-case-report/349210/",{"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/thyroid-collision-carcinoma-a-case-report/349210.png","ImageObject",300,407,{"name":92,"@type":93},"Adam","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-27","2026-09-22",true,{"@type":102,"interactionType":103,"userInteractionCount":105},"InteractionCounter",{"@type":104},"ViewAction",12,{"@type":107,"mainEntity":108},"FAQPage",[109,115,119],{"name":110,"@type":111,"acceptedAnswer":112},"What makes a thyroid collision tumor clinically challenging in this case?","Question",{"text":113,"@type":114},"The synchronous coexistence of PTC and MTC is uncommon and can mimic other metastatic patterns, requiring careful correlation of cytology, histology, and tumor markers.","Answer",{"name":116,"@type":111,"acceptedAnswer":117},"What were the main presenting symptoms of the patient?",{"text":118,"@type":114},"The patient had a painless anterior neck mass and voice hoarseness at presentation.",{"name":120,"@type":111,"acceptedAnswer":121},"How were PTC and MTC ultimately identified?",{"text":122,"@type":114},"Preoperative FNA of cervical lymph nodes suggested malignant epithelioid cells consistent with likely MTC, while post-operative histopathology showed PTC in the right lobe and concurrent MTC in central lymph nodes.","https://schema.org",{"og:url":83,"og:type":125,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":127,"canonical":83},"index,follow",{"doc_id":129,"site_id":62},349210,1790174990,{"code":4,"msg":5,"data":132},{"doc_id":129,"user_id":133,"nickname":92,"user_avatar":134,"doc_module":4,"category_id":34,"category_name":35,"doc_title":65,"doc_description":67,"doc_content":135,"file_id":136,"file_url":137,"file_type":138,"file_size":139,"view_count":105,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":24,"language":140,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":141,"faqs":142,"seo_title":143,"seo_description":67,"update_tm":144,"read_time":145},1374404737137,"https://ap-avatar.wpscdn.com/davatar_155a257f0dc6eb9ab79c44ca47cae57d","Iranian Journal of Pathology | ISSN: 2345-3656  \nThyroid Collision Carcinoma: A Case Report  \nZahra Miri 1, Sareh Etemad 2, Golnaz Ghayyem Hassankhani 3 , Mahsa Akbari Oryani2  \n1. Department of Pathology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran  \n2. Department of Pathology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran  \n3. Mashhad University of Medical Sciences, Mashhad, Iran  \n\n| KEYWORDS |  |  | ABSTRACT |\n| --- | --- | --- | --- |\n| Collision tumor, Thyroid, Papillary carcinoma, Medullary carcinoma\u003Cbr>Scan to discover online\u003Cbr>|  |  | Background & Objective: Thyroid cancer is one of the most prevalent endocrine neoplasms. Papillary thyroid carcinoma (PTC) and Medullary thyroid carcinoma (MTC) are two different types of thyroid cancers. The synchronous occurrence of PTCand MTC is a rare phenomenon, but it can present as a thyroid collision tumor. The purpose of this case report is to highlight a rare presentation of a collision tumor and its associated diagnostic challenges.\u003Cbr>Case Report: In this case report, a 61-year-old female patient presented with a painless anterior neck mass and voice hoarseness. She had a previous history of benign multinodular goiter and left lobectomy. Preoperative fine needle aspiration (FNA) biopsy of neck lymph nodes showed malignant epithelioid cells with anisonucleosis, plasmacytoid and spindle-like morphology, consistent with metastatic carcinoma, likely MTC. She underwent completion total thyroidectomy and histopathology investigations post-operation showed PTC in right lobe and the remnant of left lobe, and concurrent MTC was detected in two out of two central lymph nodes. On follow up patient had no signs of recurrence.\u003Cbr>Conclusion: This case highlights the importance of careful histological assessment of thyroid masses and lymph nodes for accurate diagnosis and the importance of longterm follow up after subtotal thyroidectomy or thyroid lobectomy. |\n| Main Subjects:\u003Cbr>Endocrine Pathology |  |  |  |\n| Received 19 Dec 2025; Accepted 18 Feb 2026; Published Online 25 Feb 2026; |  |  |  |\n|  10.22034/ijp.2026.2077955.3588 |  |  |  |\n| Corresponding Information: | Sareh Etemad, Department of Pathology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. Email: [etemadsr2@mums.ac.ir](etemadsr2@mums.ac.ir) |  |  |\n| Copyright © 2026. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The license also allows users to adapt, remix,\u003Cbr>transform, and build upon the material for any purpose, including commercial use. |  |  |  |\n\nIntroduction  \nThyroid cancer is one of the most common endocrine neoplasms and occur more frequently in women (1,2) . In the last decades, the incidence of thyroid cancer has increased, probably due to use of more accurate diagnostic tools such as ultrasound and fine-needle aspiration (FNA) (2) .  \nPapillary thyroid carcinoma (PTC) is the most common type of malignant thyroid tumors that arises from thyroid follicular cells (3,4) . Medullary thyroid carcinoma (MTC) is a rare form of thyroid cancer that originates from parafollicular C cells, which produce calcitonin (5,6) . Most MTC cases are sporadic, but about 20-30% are hereditary (6). The hereditary form is associated with multiple endocrine neoplasia type 2 (MEN 2) syndrome (6) .  \nThe concurrent occurrence of PTC and MTC is uncommon, but it can present as either a mixed tumor or a collision tumor (7,8) . Thyroid collision tumors are rare and account for only about 1% of all thyroid cancers (9) . The most common combination is synchronous PTC/MTC, followed by PTC/follicular thyroid cancer (FTC) (10) .  \nIn this report, we present a rare case of a PTC/MTC thyroid collision tumor with an uncommon presentation. This case repor","cbCaihhadOGItool","https://ap.wps.com/l/cbCaihhadOGItool","pdf",1384806,"English","# Introduction\n# Case Report\n## Clinical presentation\n## Diagnostic workup\n# Conclusion","[{\"question\":\"What makes a thyroid collision tumor clinically challenging in this case?\",\"answer\":\"The synchronous coexistence of PTC and MTC is uncommon and can mimic other metastatic patterns, requiring careful correlation of cytology, histology, and tumor markers.\"},{\"question\":\"What were the main presenting symptoms of the patient?\",\"answer\":\"The patient had a painless anterior neck mass and voice hoarseness at presentation.\"},{\"question\":\"How were PTC and MTC ultimately identified?\",\"answer\":\"Preoperative FNA of cervical lymph nodes suggested malignant epithelioid cells consistent with likely MTC, while post-operative histopathology showed PTC in the right lobe and concurrent MTC in central lymph nodes.\"}]","Thyroid Collision Carcinoma - A Case Report | PDF",1790082220,13]