[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-seo-455210-105":3,"detail-sidebar-cat-0-en-105":81,"doc-detail-455210-en":130},{"code":4,"msg":5,"data":6},0,"ok",{"site_id":7,"language":8,"slug":9,"title":10,"keywords":11,"description":12,"schema_data":13,"social_meta":74,"head_meta":76,"extra_data":78,"updated_unix":80},105,"en","delayed-aggressive-local-recurrence-of-chondroblastic-osteosarcoma-3-years-after-an-excellent-pathological-response-a-case-report","Delayed Aggressive Local Recurrence of Chondroblastic Osteosarcoma - 3 Years After an Excellent Pathological Response - A Case Report","","Late recurrence of osteosarcoma after a prolonged disease-free interval presents an uncommon but major clinical risk, reflecting persistent microscopic residual disease despite initial treatment. This report describes a 19-year-old male with chondroblastic osteosarcoma of the proximal tibia treated using neoadjuvant chemotherapy and limb-salvage surgery. He achieved wide (R0) resection margins and an excellent Huvos Grade IV response (>95% necrosis). Three years later, he developed an aggressive local recurrence requiring below-knee amputation for control. The case emphasizes tumor dormancy and the need for lifelong oncologic surveillance and improved detection strategies.",{"@graph":14,"@context":73},[15,34,56],{"@type":16,"itemListElement":17},"BreadcrumbList",[18,23,27,31],{"item":19,"name":20,"@type":21,"position":22},"https://docshare.wps.com","Home","ListItem",1,{"item":24,"name":25,"@type":21,"position":26},"https://docshare.wps.com/document/","Document",2,{"item":28,"name":29,"@type":21,"position":30},"https://docshare.wps.com/document/healthcare/","Healthcare",3,{"item":32,"name":10,"@type":21,"position":33},"https://docshare.wps.com/document/delayed-aggressive-local-recurrence-of-chondroblastic-osteosarcoma-3-years-after-an-excellent-pathological-response-a-case-report/455210/",4,{"url":32,"name":10,"@type":35,"image":36,"author":41,"headline":10,"publisher":44,"fileFormat":47,"inLanguage":8,"description":12,"dateModified":48,"datePublished":49,"encodingFormat":47,"isAccessibleForFree":50,"interactionStatistic":51},"DigitalDocument",{"url":37,"@type":38,"width":39,"height":40},"https://docshare.wps.com/thumbnails/delayed-aggressive-local-recurrence-of-chondroblastic-osteosarcoma-3-years-after-an-excellent-pathological-response-a-case-report/455210.png","ImageObject",300,407,{"name":42,"@type":43},"Mafia Boss","Person",{"url":19,"name":45,"@type":46},"DocShare","Organization","application/pdf","2026-10-30","2026-09-30",true,{"@type":52,"interactionType":53,"userInteractionCount":55},"InteractionCounter",{"@type":54},"ViewAction",10,{"@type":57,"mainEntity":58},"FAQPage",[59,65,69],{"name":60,"@type":61,"acceptedAnswer":62},"Why is late recurrence of osteosarcoma considered clinically significant?","Question",{"text":63,"@type":64},"Late recurrence after a long disease-free interval is uncommon but indicates failure to eradicate microscopic residual disease. It creates a deceptive period of remission that can delay recognition and treatment.","Answer",{"name":66,"@type":61,"acceptedAnswer":67},"What treatment outcomes were achieved initially in this case?",{"text":68,"@type":64},"The patient received standard multimodal therapy, including neoadjuvant chemotherapy and limb-salvage surgery. He had wide (R0) surgical margins and an excellent Huvos Grade IV pathological response (>95% necrosis).",{"name":70,"@type":61,"acceptedAnswer":71},"What happened after the 3-year disease-free interval, and what was required for local control?",{"text":72,"@type":64},"After 3 years without disease, he presented with aggressive and extensive local recurrence in the residual tibia. Local control ultimately required a below-knee amputation.","https://schema.org",{"og:url":32,"og:type":75,"og:title":10,"og:site_name":45,"og:description":12},"article",{"robots":77,"canonical":32},"index,follow",{"doc_id":79,"site_id":7},455210,1790962863,{"code":4,"msg":82,"data":83},"success",[84,88,92,96,101,106,110,115,120,123,126],{"id":22,"doc_module":4,"doc_module_name":25,"category_name":85,"show_sort_weight":86,"slug":87},"Story & Novel",90,"story-novel",{"id":26,"doc_module":4,"doc_module_name":25,"category_name":89,"show_sort_weight":90,"slug":91},"Literature",80,"literature",{"id":33,"doc_module":4,"doc_module_name":25,"category_name":93,"show_sort_weight":94,"slug":95},"Exam",70,"exam",{"id":97,"doc_module":4,"doc_module_name":25,"category_name":98,"show_sort_weight":99,"slug":100},5,"Comic",60,"comic",{"id":102,"doc_module":4,"doc_module_name":25,"category_name":103,"show_sort_weight":104,"slug":105},6,"Technology",50,"technology",{"id":107,"doc_module":4,"doc_module_name":25,"category_name":29,"show_sort_weight":108,"slug":109},7,40,"healthcare",{"id":111,"doc_module":4,"doc_module_name":25,"category_name":112,"show_sort_weight":113,"slug":114},8,"Research & Report",30,"research-report",{"id":116,"doc_module":4,"doc_module_name":25,"category_name":117,"show_sort_weight":118,"slug":119},9,"Religion & Spirituality",20,"religion-spirituality",{"id":118,"doc_module":4,"doc_module_name":25,"category_name":121,"show_sort_weight":118,"slug":122},"World Cup","world-cup",{"id":55,"doc_module":4,"doc_module_name":25,"category_name":124,"show_sort_weight":55,"slug":125},"Lifestyle","lifestyle",{"id":127,"doc_module":4,"doc_module_name":25,"category_name":128,"show_sort_weight":97,"slug":129},19,"General","general",{"code":4,"msg":82,"data":131},{"doc_id":79,"user_id":132,"nickname":42,"user_avatar":133,"doc_module":4,"category_id":107,"category_name":29,"doc_title":10,"doc_description":12,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":55,"is_deleted":4,"is_public":22,"is_downloadable":22,"audit_status":22,"page_count":102,"language":139,"language_code":8,"site_id":7,"html_lang":8,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":12,"update_tm":143,"read_time":144,"preview_page_count":4},962090760730,"https://ap-avatar.wpscdn.com/davatar_9964176cb1d06d4a9deccf72a44ae3dc","Clinical Case Reports  \nCASE REPORT  OPEN ACCESS   \nDelayed Aggressive Local Recurrence of Chondroblastic Osteosarcoma 3 Years After an Excellent Pathological Response: A Case Report  \nAbdul Hannan1 | Bilal Aslam1 | Natasha Hastings2 | Deepa Lachhman Das3 | Zahra Sania4 | Marium Mansoor5 | Fazeela Bibi6 | Khalil El Abdi7 | Samreen Najeeb4 | Kristen Batten8 | Manisha Kumari3 | Said Hamid Sadat9   \n1University College of Medicine and Dentistry, University of Lahore, Lahore, Pakistan | 2School of Medicine, St. George's University, St. George, Grenada | 3Indus Medical College, Tando Muhammad Khan, Pakistan | 4Women Medical and Dental College, Khyber Medical University, Peshawar, Pakistan | 5Fatima Jinnah Medical University, Lahore, Pakistan | 6Jinnah Medical and Dental College, Kirachi, Pakistan | 7Faculty of Medicine and Pharmacy of Rabat, Mohammed V University, Rabat, Morocco | 8St. James School of Medicine, Park Ridge, Illinois, USA | 9Kabul University of Medical Sciences, Kabul, Afghanistan  \nCorrespondence: Said Hamid Sadat ([saidhamidsadat788@gmail.com](saidhamidsadat788@gmail.com))  \nReceived: 28 August 2025 | Revised: 10 December 2025 | Accepted: 22 December 2025  \nKeywords: late relapse | local recurrence | oncologic surveillance | osteosarcoma | tumor dormancy  \nABSTRACT  \nLate recurrence of osteosarcoma after a prolonged disease-free interval is an uncommon but significant clinical challenge, representing a failure of primary therapy to eradicate microscopic residual disease. We present the case of a 19-year-old male diagnosed with chondroblastic osteosarcoma of the proximal tibia who was treated with standard multimodal therapy, including neoadjuvant chemotherapy and limb-salvage surgery. He achieved wide (R0) surgical margins and an excellent (Huvos Grade IV,> 95% necrosis) pathological response. After a 3-year disease-free interval, he presented with an aggressive and extensive local recurrence in the residual tibia, which ultimately necessitated a below-knee amputation for local control. This case demonstrates that an excellent initial pathological response and wide surgical margins do not preclude the risk of a delayed and highly aggressive relapse in osteosarcoma. It serves as a critical reminder that a “cure” is provisional and underscores the absolute necessity of indefinite, long-term oncologic surveillance for all survivors. The phenomenon of late recurrence highlights the urgent need for research into tumor dormancy and the development of surveillance tools capable of detecting minimal residual disease.  \n1 | Introduction  \nOsteosarcoma is the most common primary malignant bone tumor in adolescents and young adults, typically arising in themetaphysis of long bones such as the proximal tibia [1] The standard of care, consisting of a multimodal approach with neoadjuvant chemotherapy, surgical resection, and adjuvant chemotherapy, has significantly improved prognosis, with 5-year survival rates for localized disease now approaching 70%[2] .  \nDespite these therapeutic advances, disease recurrence remains a primary cause of treatment failure and a significant clinical  \nchallenge [3] . Local recurrence typically occurs within the first 2 years following initial treatment, and relapse after a 3-year disease-free interval is less common [4] . This period of deceptive quiescence can create a false sense of security for both patients and clinicians, making late recurrences particularly challenging.  \nHere, we present the case of a 19-year-old male with chondroblastic osteosarcoma of the proximal tibia who, after successful limb-salvage surgery and chemotherapy, experienced a highly aggressive local recurrence 3 years into remission. The objective of this report is to highlight the unpredictable nature of  \nThis is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.  \n© 2026 The","cbCaiayEdjVCLnWw","https://ap.wps.com/l/cbCaiayEdjVCLnWw","pdf",516040,"English","# Introduction\n# Case History\n# Investigations and Differential Diagnosis","[{\"question\":\"Why is late recurrence of osteosarcoma considered clinically significant?\",\"answer\":\"Late recurrence after a long disease-free interval is uncommon but indicates failure to eradicate microscopic residual disease. It creates a deceptive period of remission that can delay recognition and treatment.\"},{\"question\":\"What treatment outcomes were achieved initially in this case?\",\"answer\":\"The patient received standard multimodal therapy, including neoadjuvant chemotherapy and limb-salvage surgery. He had wide (R0) surgical margins and an excellent Huvos Grade IV pathological response (\\u003e95% necrosis).\"},{\"question\":\"What happened after the 3-year disease-free interval, and what was required for local control?\",\"answer\":\"After 3 years without disease, he presented with aggressive and extensive local recurrence in the residual tibia. Local control ultimately required a below-knee amputation.\"}]","Delayed Aggressive Local Recurrence of Chondroblastic Osteosarcoma - 3 Years After an Excellent Pathological Response - A Case Report | PDF",1790742376,15]