Lu SQ, Lv W, Liu YJ, Deng H. Fat-poor renal angiomyolipoma with prominent cystic degeneration: A case report and review of the literature. World J Clin Cases 2023; 11(2): 417-425 [PMID: 36686346 DOI: 10.12998/wjcc.v11.i2.417]
Corresponding Author of This Article
Huan Deng, MD, PhD, Professor, Department of Pathology, The Fourth Affiliated Hospital of Nanchang University, No. 133 South Guangchang Road, Nanchang 330003, Jiangxi Province, China. beandeng@ncu.edu.cn
Research Domain of This Article
Urology & Nephrology
Article-Type of This Article
Case Report
Open-Access Policy of This Article
This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
World J Clin Cases. Jan 16, 2023; 11(2): 417-425 Published online Jan 16, 2023. doi: 10.12998/wjcc.v11.i2.417
Fat-poor renal angiomyolipoma with prominent cystic degeneration: A case report and review of the literature
Shi-Qi Lu, Wei Lv, You-Jun Liu, Huan Deng
Shi-Qi Lu, Medical College, Nanchang University, Nanchang 330006, Jiangxi Province, China
Wei Lv, Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610044, Sichuan Province, China
You-Jun Liu, Department of Radiology, The Fourth Affiliated Hospital of Nanchang University, Nanchang 330003, Jiangxi Province, China
Huan Deng, Department of Pathology, The Fourth Affiliated Hospital of Nanchang University, Nanchang 330003, Jiangxi Province, China
Author contributions: Lu SQ and Lv W carried pathological analyses and drafted the manuscript; Liu YJ analyzed the images; Deng H conceived of this study and drafted the manuscript; and all authors issued final approval for the version to be submitted.
Supported bythe National Science Foundation of China, No. 81860490 and 82160546; and the Science Foundation of Jiangxi Province, No. 20202BBG73027.
Informed consent statement: Informed written consent was obtained from the patient for publication of this report and any accompanying images.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Huan Deng, MD, PhD, Professor, Department of Pathology, The Fourth Affiliated Hospital of Nanchang University, No. 133 South Guangchang Road, Nanchang 330003, Jiangxi Province, China. beandeng@ncu.edu.cn
Received: October 7, 2022 Peer-review started: October 7, 2022 First decision: November 4, 2022 Revised: November 16, 2022 Accepted: December 21, 2022 Article in press: December 21, 2022 Published online: January 16, 2023
Abstract
BACKGROUND
Angiomyolipoma (AML), the most common benign tumor of the kidney, is usually composed of dysmorphic blood vessels, smooth muscle, and mature adipose tissue. To our knowledge, AML with cystic degeneration has rarely been documented. Cystic degeneration, hemorrhage, and a lack of fat bring great challenges to the diagnosis.
CASE SUMMARY
A 60-year-old man with hypertension presented with a 5-year history of cystic mass in his left kidney. He fell 2 mo ago. A preoperative computed tomography (CT) scan showed a mixed-density cystic lesion without macroscopic fat density, the size of which had increased compared with before, probably due to hemorrhage caused by a trauma. Radical nephrectomy was performed. Histopathological studies revealed that the lesion mainly consisted of tortuous, ectatic, and thick-walled blood vessels, mature adipose tissue, and smooth muscle-like spindle cells arranged around the abnormal blood vessels. The tumor cells exhibited positivity for human melanoma black-45, Melan-A, smooth muscle actin, calponin, S-100, and neuron-specific enolase, rather than estrogen receptor, progesterone receptor, CD68, and cytokeratin. The Ki-67 labeling index was less than 5%. The final diagnosis was a fat-poor renal AML (RAML) with prominent cystic degeneration.
CONCLUSION
When confronting a large renal cystic mass, RAML should be included in the differential diagnosis.
Core Tip: Angiomyolipoma (AML) is a clinically common benign kidney tumor. The majority of classic AMLs can be diagnosed preoperatively through radiological technology because of the appearance of an adipose component. We report a rare case of a fat-poor renal AML (RAML) with prominent cystic degeneration. The establishment of RAML diagnosis is challenging because of the lack of specificity of imaging features. Histopathological and immunohistochemical examinations show that the three classic components express AML markers, supporting the final diagnosis.
