Indian Journal of Pathology and Oncology 2020;7(3):435–440 Content available at: https://www.ipinnovative.com/open-access-journals Indian Journal of Pathology and Oncology Journal homepage: www.ipinnovative.com Original Research Article Angiomyolipoma managed by partial nephrectomy: Outcomes and follow-up R B Nerli 1, *, Adarsh C Sanikop 2 , Sushant Deole 1 , Sreeharsha Nutalapati 1 , Shridhar C Ghagane 1 , Saziya R Bidi 3 , Neeraj S Dixit 3 , Murigendra B Hiremath 4 1 Dept. of Urology, J N Medical College, KLE Academy of Higher Education & Research (Deemed-to-be-University), JNMC Campus, Belagavi, Karnataka, India 2 Dept. of Pathology, J N Medical College, KLE Academy of Higher Education & Research (Deemed-to-be-University), JNMC Campus, Belagavi, Karnataka, India 3 Dept. of Urology, KLES Kidney Foundation, KLES Dr. Prabhakar Kore Hospital & Medical Research Centre, Belagavi, Karnataka, India 4 Dept. of Biotechnology and Microbiology, Karnatak University, Dharwad, Karnataka, India ARTICLE INFO Article history: Received 28-11-2019 Accepted 03-04-2020 Available online 19-08-2020 Keywords: Angiomyolipoma Nephron sparing surgery Renal mass ABSTRACT Introduction: Angiomyolipoma (AML) is a benign neoplasm and consists of thick-walled poorly organized blood vessels, smooth muscle, and varying levels of mature adipose tissue. We evaluated the impact of clinical characteristics, particularly tumor diameter, and surgical treatment in the form of partial nephrectomy on the outcome of sporadic renal AML. Materials and Methods: Patients undergoing partial nephrectomy during the period Jan 2000 to Dec 2016 with a final diagnosis of angiomyolipoma formed the study group. Patient demographic data was collected, and data from during and after surgery was also reviewed. Results: The median age of the patients was 51 (38-55) years. At presentation, most patients were asymptomatic (6/8, 75%) with the AML presenting as an incidental finding on imaging done for other reasons. There was classical triphasic AML, consisting of elements of adipose tissue, smooth muscle and abnormal blood vessels, in 5/10 tumours (50%). The more aggressive epitheliod variant AML was present in 2/10 (20%). The median follow-up of the patients was 38 (29-64) months. During the follow-up period one (12.5%) patient who had two lesions progressively showed evidence of rising creatinine and decreasing creatinine clearance. Conclusions: AML is a benign renal neoplasm and should be treated initially conservatively. Surgical intervention when required should be nephron sparing so as to reduce the incidence of perioperative complications, loss of renal units, and development of CKD. © 2020 Published by Innovative Publication. This is an open access article under the CC BY-NC license (https://creativecommons.org/licenses/by-nc/4.0/) 1. Introduction Angiomyolipoma (AML) accounts for less than 10% of renal tumors, with autopsy series and ultrasound-screened populations showing incidences of 0.3% and 0.13%, respectively, in the general population. 1,2 It is a benign neoplasm and consists of thick-walled poorly organized blood vessels, smooth muscle, and varying levels of mature adipose tissue. 3,4 Initially it was considered to be a form of * Corresponding author. E-mail address: rbnerli@gmail.com (R. B. Nerli). hamartoma however, recent evidence has suggested that it is neoplastic in origin with evidence of a monoclonal, rather than polyclonal, source. 1,5 Angiomyolipoma derives itself from perivascular epithelioid cells, belonging to a group of tumors referred to as PEComas (perivascular epithelioid cell tumors). 4,6 The tumor is predominantly found in females, 1 is rare before puberty, suggesting a potential hormonal influence and strongly expresses estrogen receptor β , progesterone receptor, and androgen receptor. 7 The most common complication related to renal AML is retroperitoneal bleeding, which has been reported in 15% https://doi.org/10.18231/j.ijpo.2020.086 2394-6784/© 2020 Innovative Publication, All rights reserved. 435