{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,14]],"date-time":"2026-11-14T10:14:34Z","timestamp":1794651274309,"version":"4.9.1"},"reference-count":15,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"1","content-domain":{"domain":["lww.com","ovid.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2023,1]]},"abstract":"<jats:p>Nephrogenic adenoma is a benign epithelial lesion of the genitourinary tract that arises from the reimplantation and proliferation of shed renal tubular cells in areas of urothelial injury and denudation. Fibromyxoid nephrogenic adenoma is a rare variant that consists of compressed spindle-shaped renal epithelial cells in a fibromyxoid background. Only 14 observations of this variant are reported in the literature. We performed a retrospective analysis of fibromyxoid nephrogenic adenomas from 3 large reference centers. We identified 43 lesions in 6 women and 36 men (2 in 1 man) with a median age of 72 years (range, 31 to 94\u00a0y). Median lesion size was 0.7\u00a0cm (range, 0.2 to 5\u00a0cm). Nephrogenic adenomas were in the bladder (n=15), prostate\/prostatic urethra (n=14), kidney (n=7), ureter (n=3), penile urethra (n=3), and urethral diverticulum (n=1). One of the kidney lesions developed in an end-stage kidney and radiologically mimicked cancer. Of 37 patients with information, 36 had predisposing conditions including prior biopsy, transurethral resection of bladder tumor, resection, Foley catheter, BCG treatment, urinary stones, (chemo)radiation, or diverticulum. Only 4\/37 (10.8%) had a history of prior irradiation. Fifteen lesions had pure fibromyxoid morphology and 28 were admixed classic and fibromyxoid patterns. Three nephrogenic adenomas involved prostatic stroma, 3 renal sinus fat, 2 muscularis propria (1 bladder, 1 renal pelvis), 1 perinephric fat, and 1 corpus spongiosum. Ten fibromyxoid nephrogenic adenomas were intermixed with urothelial carcinoma, 1 with prostate adenocarcinoma, and 1 with malignant melanoma. By immunohistochemistry, PAX8 was positive in all the examined lesions (n=31). Napsin A was negative in all examined fibromyxoid nephrogenic adenomas (n=30). Twenty of them had classic nephrogenic adenoma component which was positive for napsin A. Similar to classic nephrogenic adenoma, fibromyxoid nephrogenic adenoma can occur anywhere along the urinary tract and is associated with a prior history that causes urothelial injury. In nearly a quarter of the cases, fibromyxoid nephrogenic adenoma extended beyond the lamina propria. Unlike previously suggested, fibromyxoid nephrogenic adenoma is not specifically related to prior radiation therapy. Awareness of this variant is important to avoid misdiagnosis and overtreatment.<\/jats:p>","DOI":"10.1097\/pas.0000000000001986","type":"journal-article","created":{"date-parts":[[2022,11,17]],"date-time":"2022-11-17T22:01:54Z","timestamp":1668722514000},"page":"37-46","update-policy":"https:\/\/doi.org\/10.1097\/lww.0000000000001000","source":"Crossref","is-referenced-by-count":13,"title":["Fibromyxoid Nephrogenic Adenoma"],"prefix":"10.1097","volume":"47","author":[{"given":"Lin","family":"Li","sequence":"first","affiliation":[{"name":"Pathology and Laboratory Medicine"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sean R.","family":"Williamson","sequence":"additional","affiliation":[{"name":"Department of Pathology, Cleveland Clinic, Cleveland, OH"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rosa P.","family":"Castillo","sequence":"additional","affiliation":[{"name":"Radiology"},{"name":"Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Katiana S.","family":"Delma","sequence":"additional","affiliation":[{"name":"Pathology and Laboratory Medicine"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mark L.","family":"Gonzalgo","sequence":"additional","affiliation":[{"name":"Desai Sethi Urology Institute"},{"name":"Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jonathan I.","family":"Epstein","sequence":"additional","affiliation":[{"name":"Pathology"},{"name":"Urology"},{"name":"Oncology, The Johns Hopkins Medical Institutions, Baltimore, MD"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Oleksandr N.","family":"Kryvenko","sequence":"additional","affiliation":[{"name":"Pathology and Laboratory Medicine"},{"name":"Radiation Oncology"},{"name":"Desai Sethi Urology Institute"},{"name":"Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"276","published-online":{"date-parts":[[2022,11,4]]},"reference":[{"key":"R1-20250608","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1016\/j.anndiagpath.2018.09.012","article-title":"Mimickers of urothelial neoplasia","volume":"38","author":"Kryvenko","year":"2019","journal-title":"Ann Diagn Pathol"},{"key":"R2-20250608","doi-asserted-by":"crossref","first-page":"653","DOI":"10.1056\/NEJMoa013413","article-title":"Derivation of nephrogenic adenomas from renal tubular cells in kidney-transplant recipients","volume":"347","author":"Mazal","year":"2002","journal-title":"N Engl J Med"},{"key":"R3-20250608","first-page":"722","article-title":"Nephrogenic adenoma of the urinary tract: a review of the microscopic appearance of 80 cases with emphasis on unusual features","volume":"8","author":"Oliva","year":"1995","journal-title":"Mod Pathol"},{"key":"R4-20250608","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1016\/j.urology.2016.04.032","article-title":"Nephrogenic adenoma: clinical features, management, and diagnostic pitfalls","volume":"95","author":"Gordetsky","year":"2016","journal-title":"Urology"},{"key":"R5-20250608","doi-asserted-by":"crossref","first-page":"831","DOI":"10.1016\/j.prp.2017.03.001","article-title":"Nephrogenic adenoma of the urinary tract: a 6-year single center experience","volume":"213","author":"Turcan","year":"2017","journal-title":"Pathol Res Pract"},{"key":"R6-20250608","doi-asserted-by":"crossref","first-page":"819","DOI":"10.1007\/s00428-013-1497-y","article-title":"Nephrogenic adenoma of the urinary tract: clinical, histological, and immunohistochemical characteristics","volume":"463","author":"Lopez","year":"2013","journal-title":"Virchows Arch"},{"key":"R7-20250608","doi-asserted-by":"crossref","first-page":"1231","DOI":"10.1097\/PAS.0b013e31802e290d","article-title":"Fibromyxoid nephrogenic adenoma: a newly recognized variant mimicking mucinous adenocarcinoma","volume":"31","author":"Hansel","year":"2007","journal-title":"Am J Surg Pathol"},{"key":"R8-20250608","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/j.prp.2015.09.013","article-title":"Fibromyxoid nephrogenic adenoma protruding in a renal cortical cyst. A rare morphological variant in an outstanding location","volume":"212","author":"Khedaoui","year":"2016","journal-title":"Pathol Res Pract"},{"key":"R9-20250608","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1089\/cren.2018.0037","article-title":"Fibromyxoid nephrogenic adenoma in the ureter","volume":"4","author":"Dropkin","year":"2018","journal-title":"J Endourol Case Rep"},{"key":"R10-20250608","doi-asserted-by":"crossref","DOI":"10.5858\/arpa.2021-0620-OA","article-title":"Nephrogenic adenoma intermixed with urothelial carcinoma: a potential mimic of divergent glandular differentiation, variant morphology, or invasion","author":"Kryvenko","year":"2022","journal-title":"Arch Pathol Lab Med"},{"key":"R11-20250608","doi-asserted-by":"crossref","first-page":"152561","DOI":"10.1016\/j.prp.2019.152561","article-title":"Common and uncommon features of nephrogenic adenoma revisited","volume":"215","author":"Santi","year":"2019","journal-title":"Pathol Res Pract"},{"key":"R12-20250608","doi-asserted-by":"crossref","first-page":"e27025","DOI":"10.1097\/MD.0000000000027025","article-title":"Nephrogenic adenoma of the renal pelvis: a rare case report and review of the literature","volume":"100","author":"Zhang","year":"2021","journal-title":"Medicine (Baltimore)"},{"key":"R13-20250608","doi-asserted-by":"crossref","first-page":"532","DOI":"10.1097\/PAS.0b013e31826f0447","article-title":"Nephrogenic adenoma: a report of 3 unusual cases infiltrating into perinephric adipose tissue","volume":"37","author":"Diolombi","year":"2013","journal-title":"Am J Surg Pathol"},{"key":"R14-20250608","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1016\/j.humpath.2019.02.005","article-title":"Perinephric myxoid pseudotumor of fat: a distinctive pseudoneoplasm most often associated with non-neoplastic renal disease","volume":"87","author":"Dashti","year":"2019","journal-title":"Hum Pathol"},{"key":"R15-20250608","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1016\/j.humpath.2020.05.007","article-title":"Napsin A is a highly sensitive marker for nephrogenic adenoma: an immunohistochemical study with a specificity test in genitourinary tumors","volume":"102","author":"Sharifai","year":"2020","journal-title":"Hum Pathol"}],"container-title":["American Journal of Surgical Pathology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.lww.com\/10.1097\/PAS.0000000000001986","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,6,8]],"date-time":"2025-06-08T21:02:05Z","timestamp":1749416525000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.lww.com\/10.1097\/PAS.0000000000001986"}},"subtitle":["A Series of 43 Cases Reassessing Predisposing Conditions, Clinical Presentation, and Morphology"],"short-title":[],"issued":{"date-parts":[[2022,11,4]]},"references-count":15,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2023]]}},"URL":"https:\/\/doi.org\/10.1097\/pas.0000000000001986","relation":{},"ISSN":["0147-5185"],"issn-type":[{"value":"0147-5185","type":"print"}],"subject":[],"published":{"date-parts":[[2022,11,4]]}}}