{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,12]],"date-time":"2025-11-12T10:00:12Z","timestamp":1762941612232,"version":"3.45.0"},"reference-count":20,"publisher":"BMJ","issue":"11","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2025,10,15]]},"published-print":{"date-parts":[[2025,11]]},"abstract":"<jats:p>Alkaptonuria, although rare, can lead to severe multisystemic manifestations, including progressive ochronosis and extensive urological complications. This case highlights an unusually diffuse stone burden involving the entire urinary tract, emphasising the importance of early recognition of classic signs such as dark urine and joint stiffness. Timely biochemical confirmation and imaging can aid in the appropriate diagnosis. Management requires a multidisciplinary approach encompassing metabolic control, surgical intervention and long-term follow-up. Greater awareness of this condition among clinicians can prevent delays in diagnosis and reduce morbidity through proactive monitoring and individualized therapeutic strategies.<\/jats:p>","DOI":"10.1136\/bcr-2025-267589","type":"journal-article","created":{"date-parts":[[2025,11,12]],"date-time":"2025-11-12T09:55:16Z","timestamp":1762941316000},"page":"e267589","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["From black urine to bladder obstruction: multidisciplinary management of extensive stone formation in alkaptonuria"],"prefix":"10.1136","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0009-0002-3623-3343","authenticated-orcid":false,"given":"Veerabadren","family":"Mylappan","sequence":"first","affiliation":[{"name":"General Medicine, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2962-5106","authenticated-orcid":false,"given":"Srinivasan","family":"Ramadurai","sequence":"additional","affiliation":[{"name":"General Medicine, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9600-1256","authenticated-orcid":false,"given":"Rajkumar","family":"Mani","sequence":"additional","affiliation":[{"name":"General Medicine, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0045-9415","authenticated-orcid":false,"given":"Sriram","family":"Krishnamoorthy","sequence":"additional","affiliation":[{"name":"Urology, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India"},{"name":"Urology, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2025,11,12]]},"reference":[{"key":"2025111201550860000_18.11.e267589.1","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1016\/bs.acc.2023.02.005","article-title":"Alkaptonuria - Past, present and future","volume":"114","author":"Davison","year":"2023","journal-title":"Adv Clin Chem"},{"key":"2025111201550860000_18.11.e267589.2","doi-asserted-by":"publisher","DOI":"10.2165\/00128071-200102040-00002"},{"key":"2025111201550860000_18.11.e267589.3","doi-asserted-by":"crossref","first-page":"339","DOI":"10.5414\/CN108608","article-title":"Renal and prostate stones composition in alkaptonuria: a case report","volume":"84","author":"Wolff","year":"2015","journal-title":"Clin Nephrol"},{"key":"2025111201550860000_18.11.e267589.4","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa021736"},{"key":"2025111201550860000_18.11.e267589.5","doi-asserted-by":"crossref","DOI":"10.1136\/bcr-2021-244240","article-title":"Alkaptonuria: clinical manifestations and an updated approach to treatment of a rare disease","volume":"14","author":"Roopnarinesingh","year":"2021","journal-title":"BMJ Case Rep"},{"key":"2025111201550860000_18.11.e267589.6","doi-asserted-by":"crossref","DOI":"10.1177\/1557988320969310","article-title":"Urological Aspects in Patients with Alkaptonuria: A Case-Control Study","volume":"14","author":"Suoub","year":"2020","journal-title":"Am J Mens Health"},{"key":"2025111201550860000_18.11.e267589.7","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1038\/s41572-024-00498-x","article-title":"Alkaptonuria","volume":"10","author":"Bernardini","year":"2024","journal-title":"Nat Rev Dis Primers"},{"key":"2025111201550860000_18.11.e267589.8","doi-asserted-by":"crossref","DOI":"10.1056\/NEJMicm2025932","article-title":"Ochronosis","volume":"384","author":"Di Matteo","year":"2021","journal-title":"N Engl J Med"},{"key":"2025111201550860000_18.11.e267589.9","doi-asserted-by":"crossref","DOI":"10.4161\/rdis.27475","article-title":"Alkaptonuria","volume":"1","author":"Mistry","year":"2013","journal-title":"Rare Dis"},{"key":"2025111201550860000_18.11.e267589.10","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1007\/s00223-020-00764-6","article-title":"Anatomical Distribution of Ochronotic Pigment in Alkaptonuric Mice is Associated with Calcified Cartilage Chondrocytes at Osteochondral Interfaces","volume":"108","author":"Hughes","year":"2021","journal-title":"Calcif Tissue Int"},{"key":"2025111201550860000_18.11.e267589.11","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1530\/EOR-2023-0112","article-title":"Ochronotic arthropathy: skeletal manifestations and orthopaedic treatment","volume":"10","author":"Salem","year":"2025","journal-title":"EFORT Open Rev"},{"key":"2025111201550860000_18.11.e267589.12","doi-asserted-by":"crossref","DOI":"10.1002\/ccr3.6729","article-title":"Dilemmas in the diagnosis and management of osteoporosis in a patient with alkaptonuria: Successful treatment with teriparatide","volume":"10","author":"Ebrahim","year":"2022","journal-title":"Clin Case Rep"},{"key":"2025111201550860000_18.11.e267589.13","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1016\/j.ajur.2015.06.003","article-title":"Extensive prostatic calculi in alkaptonuria: An unusual manifestation of rare disease","volume":"2","author":"Sali","year":"2015","journal-title":"Asian J Urol"},{"key":"2025111201550860000_18.11.e267589.14","doi-asserted-by":"crossref","DOI":"10.3390\/cells13121072","article-title":"Alkaptonuria: From Molecular Insights to a Dedicated Digital Platform","volume":"13","author":"Milella","year":"2024","journal-title":"Cells"},{"key":"2025111201550860000_18.11.e267589.15","first-page":"51","article-title":"Quick Diagnosis of Alkaptonuria by Homogentisic Acid Determination in Urine Paper Spots","volume":"31","author":"Jacomelli","year":"2017","journal-title":"JIMD Rep"},{"key":"2025111201550860000_18.11.e267589.16","doi-asserted-by":"crossref","DOI":"10.4103\/0378-6323.45142","article-title":"From darkening urine to early diagnosis of alkaptonuria","volume":"74","author":"Peker","year":"2008","journal-title":"Indian J Dermatol Venereol Leprol"},{"key":"2025111201550860000_18.11.e267589.17","doi-asserted-by":"crossref","DOI":"10.1038\/s41598-023-41200-7","article-title":"Homogentisate 1,2-dioxygenase (HGD) gene variants in young Egyptian patients with alkaptonuria","volume":"13","author":"Abdelkhalek","year":"2023","journal-title":"Sci Rep"},{"key":"2025111201550860000_18.11.e267589.18","first-page":"104340","article-title":"Adequacy of nitisinone for the management of alkaptonuria","volume":"80","author":"Abbas","year":"2022","journal-title":"Ann Med Surg (Lond)"},{"key":"2025111201550860000_18.11.e267589.19","doi-asserted-by":"publisher","DOI":"10.1136\/annrheumdis-2014-206033"},{"key":"2025111201550860000_18.11.e267589.20","doi-asserted-by":"crossref","first-page":"61","DOI":"10.2478\/enr-2023-0008","article-title":"Nutritional interventions for patients with alkaptonuria: A minireview","volume":"57","author":"Imrich","year":"2023","journal-title":"Endocr Regul"}],"container-title":["BMJ Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bcr-2025-267589","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,11,12]],"date-time":"2025-11-12T09:55:18Z","timestamp":1762941318000},"score":1,"resource":{"primary":{"URL":"https:\/\/casereports.bmj.com\/lookup\/doi\/10.1136\/bcr-2025-267589"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,11]]},"references-count":20,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2025,11,12]]},"published-print":{"date-parts":[[2025,11]]}},"alternative-id":["10.1136\/bcr-2025-267589"],"URL":"https:\/\/doi.org\/10.1136\/bcr-2025-267589","relation":{},"ISSN":["1757-790X"],"issn-type":[{"value":"1757-790X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,11]]}}}