Urology Annals
About UA | Search | Ahead of print | Current Issue | Archives | Instructions | Online submissionLogin 
Urology Annals
  Editorial Board | Subscribe | Advertise | Contact
Users Online: 388   Home Print this page  Email this page Small font size Default font size Increase font size

Table of Contents
Year : 2020  |  Volume : 12  |  Issue : 2  |  Page : 167-171  

Sporadic giant renal angiomyolipoma: A case report and literature review of clinical presentation, diagnosis, and treatment options

1 Department of Urology, King Abdullah Bin AbdulAziz University Hospital, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia
2 Department of Urology, King Saud Medical City, Riyadh, Saudi Arabia
3 Department of Histopathology, Riyadh Regional Lab and Blood Bank, Riyadh, Saudi Arabia
4 Department of Urology, King Saud Medical City, Riyadh, Saudi Arabia; Department of Urology, Tanta University Hospital, Tanta, Egypt

Date of Submission19-Feb-2019
Date of Acceptance26-Sep-2019
Date of Web Publication14-Apr-2020

Correspondence Address:
Dr. Ali Abdel Raheem
Department of Urology, King Saud Medical City, Riyadh; Department of Urology, Tanta University Hospital, Tanta, Egypt

Login to access the Email id

DOI: 10.4103/UA.UA_26_19

Rights and Permissions

Giant angiomyolipoma (AML) is uncommon benign renal neoplasm that occurs sporadic or in association with tuberous sclerosis syndrome. There is no specific cutoff tumor size and/or weight to define giant AMLs. Ovarian stimulation hormones might cause a marked increase in its size and subsequent bleeding risk. Incidental findings are not common in those patients as mass-associated symptoms always present. Computed tomography scan is the standard diagnostic imaging study except for tumors with poor fat content. According to the clinical presentation, site and side of renal involvement giant sporadic AMLs have different treatment options, for example, active surveillance, selective renal artery embolization, nephron-sparing surgery, and/or radical nephrectomy. In the present case report, we present a 22-year-old female with huge right renal mass (29 cm × 23 cm × 21 cm) and treated with right radical nephrectomy which proved to be renal AML on pathology examination.

Keywords: Angiomyolipoma, giant, sporadic, treatment

How to cite this article:
Alshehri M, Hakami B, Aljameel N, Alayyaf M, Raheem AA. Sporadic giant renal angiomyolipoma: A case report and literature review of clinical presentation, diagnosis, and treatment options. Urol Ann 2020;12:167-71

How to cite this URL:
Alshehri M, Hakami B, Aljameel N, Alayyaf M, Raheem AA. Sporadic giant renal angiomyolipoma: A case report and literature review of clinical presentation, diagnosis, and treatment options. Urol Ann [serial online] 2020 [cited 2021 Nov 29];12:167-71. Available from: https://www.urologyannals.com/text.asp?2020/12/2/167/282394

   Introduction Top

Angiomyolipoma (AML) is the most common benign renal tumors and represents up to 3% of renal masses.[1] AMLs are usually diagnosed incidentally; however, with large-size AMLs (>4 cm) symptoms such as hemorrhage, pain, palpable mass, and mass-associated symptoms may present. A potentially life-threatening hemorrhage may occur due to abnormal vasculature, and/or rupture aneurysms require urgent intervention.[2]

Giant AMLs are extremely rare, with no specific cutoff tumor size or weight to define it. Few articles have reported cases of sporadic AMLs with a size of >20 cm.[3],[4],[5],[6],[7],[8],[9],[10] In this article, we represent a case of sporadic AML with a size of 29 cm and weight of 9000 g treated at our urology department, with a thorough literature review of clinical presentation, diagnosis, and treatment options for sporadic AMLs (>20 cm).

   Case Report Top

A 22-year-old female was referred to the King Saud Medical City Outpatient Urology Clinic for the assessment of large right abdominal swelling. She gave a history of right-sided abdominal swelling for the past 3 years which slowly increase in size and was associated with vague abdominal pain. Otherwise, she had no other urinary or gastrointestinal symptoms. She was diagnosed recently to have hypertension treated with angiotensin-converting enzyme inhibitor (ACEI).

On examination, the abdomen was soft with large abdominal swelling, smooth surface, solid in consistency, and not associated with tenderness, with superficial dilated veins in the anterior abdomen, lower back, and right lower limb [Figure 1]a.
Figure 1: Large abdominal swelling (a) before “left side image” and (b) during the surgery “right side image”

Click here to view

All laboratory investigations were within the normal values. Computed tomography (CT) abdomen and pelvis with contrast showed multilocular multicystic fluid containing mass arising from the right kidney, measuring 29 cm × 23 cm × 21 cm with no calcifications or soft-tissue enhancement, nor fat content [Figure 2]. There was no enlarged lymph node in the abdomen and pelvis. The chest X-ray was normal. Initial diagnosis was multilocular cystic nephroma, but renal hydatid cyst was suspected. Therefore, we started prophylactic albendazole 4 weeks before the surgery. An informed consent was obtained from the patient for the intervention and its possible complications. Actually, we have decided to perform the right radical nephrectomy based on preoperative images showing that the huge mass originates from the right kidney, as we believe that other treatment options such as partial nephrectomy (PN) and/or angioembolization would not be feasible treatment for such a huge mass. The right hemi-chevron approach with midline extension incision [Figure 1]b was performed with all precautions for hydatid cyst lesion.
Figure 2: Abdominal and pelvic computed tomography scan with contrast showing multilocular multicystic fluid containing mass arising from the right kidney, measuring 29 cm × 23 cm × 21cm with no calcifications or soft-tissue enhancement, nor fat content

Click here to view

Grossly, the mass was well circumscribed, measured 30 cm × 22 cm × 20 cm and weighted 9000 g with an attached 3 cm segment of dilated ureter [Figure 3]a. Cross-section cuts revealed tan-white-yellowish, homogenous gelatinous mass arising from the kidney parenchyma with no areas of hemorrhage or necrosis. Multiple dilated cystic spaces filled with clear yellowish fluid with smooth thin walls were seen [Figure 3]b. There was a thin normal cortex in the lower pole. Microscopic examination [Figure 4]a and b] revealed a mass composed predominantly of smooth muscles within an edematous stroma, island of mature fat, and thick blood vessels are also noted throughout the tumor, with no evidence of malignancy or epithelioid elements. Tissue immunohistochemical staining showed a strong positivity of smooth muscle actin, caldesmon, and estrogen receptor. No definite staining is seen with human melanoma black (45) and CD117. CAE1/AE3 highlighted entrapped dilated tubules. These features are consistent with AML. Tumor is entirely excised with no evidence of malignancy seen.
Figure 3: Gross picture pathology (a) specimen weight 9000 gram “left side image” and (b) cross cut section of the mass “right side image”

Click here to view
Figure 4: Microscopic examination (H and E) of the tumor with medium and high power on the left (a) and right images (b), respectively

Click here to view

Postoperatively, she was doing fine and had a normal renal function during follow-up, as well as, she no longer use ACEI for the treatment of hypertension. Radiologically, there was no evidence of tumor recurrence at a 15-month follow-up.

   Discussion Top

AML is uncommon benign renal neoplasm which composed a variable mixture of mature adipose tissues, blood vessels, and fully differentiated smooth muscles. AML is possibly derived from perivascular epithelioid cells, it predominates in female, and recent evidences suggest strong tumor positivity to female hormones with increasing its size during pregnancy[11] and oral contraceptive therapy.[12] More recently, Watanabe et al. have reported a massive increase in AML size from 1 to 18 cm for a 40-year-old female after 10 months of treatment with ovarian stimulation hormone.[13]

Similar to small-sized AMLs, giant AMLs (>20 cm) might occur in sporadic form[3],[4],[5],[6],[7],[8],[9],[10] or in association with genetic syndromes like tuberous sclerosis complex (TSC).[14],[15] To the best of our knowledge, there is no specific cutoff tumor size and/or weight to define giant AMLs. Previous case reports showed that AMLs may reach size up to range of 25–39 cm and weight of 3818–17,900 g. Of note, our patient had a tumor size of 29 cm in largest dimension and weight of 9000 g.

According to our literature review [Table 1], it seems that the incidental finding of sporadic AMLs (>20 cm) is not reported since all patients have symptoms and signs of large abdominal mass effect.[3],[4],[5],[6],[7],[8],[9],[10] Patients commonly present with abdominal swelling and fullness, dull aching, or vague abdominal pain; the bloating sensation which might associated with nausea and vomiting. The clinical presentation usually has an insidious onset and slowly progressive course. A serious presentation of giant AMLs is bleeding either retroperitoneal or into the collecting system which if massive might associated with hemodynamic instability and require resuscitation with urgent surgical intervention.[8]
Table 1: Clinical presentation, diagnosis, and treatment options of angiomyolipomas

Click here to view

AMLs have characteristic findings on radiological evaluation to differentiate it from renal cell carcinoma (RCC). Ultrasound usually reveals a hyperechogenic well-circumscribed mass with shadowing. CT with contrast is diagnostic of AML by the presence of fat (confirmed by a value of –20–80 HU on imaging).[16] The absence of fat attenuation usually makes it difficult to differentiated AML from RCC, as in our case, the CT scan did not show fat content in the mass (only microscopic visible fat). Similarly, Nepple et al. have reported a large cystic renal mass (35 cm) without fat density on CT that on histopathological examination was found to be a fat-poor AML with predominant epithelioid cells.[3] Of note, about 5% of AMLs do not show fat attenuation on imaging studies.[16]

The treatment decision of sporadic giant AMLs is greatly determined if one or both renal units are involved, presence of normal renal tissue to preserve it, as well as, the patient clinical presentation. Most of cases of giant AMLs are symptomatic and treated with radical nephrectomy due to involvement of the whole renal unit[3],[4],[5],[6],[7],[9],[10] and that was the treatment option we offered to our patient. In some occasions, if the patient has no symptoms active surveillance might be an option. Cavicchioli et al. have reported a successful active surveillance protocol with serial magnetic resonance imaging follow-up every 4–5 months for the treatment of male patient with bilateral giant AMLs (the right mass size was 28.5 cm, and the left mass size was 27.5 cm), with abdominal enlargement is the only complaint and no pain, hematuria, or other related symptoms.[5] In patients who developed severe bleeding that affects the hemodynamic status, urgent intervention is required. Albersheim-Carter et al. have reported on a 60-year-old female patient with left side giant AML (30 cm) who presented with shock due to massive retroperitoneal bleeding secondary to hemorrhage from the tumor and was treated with intravenous fluid replacement, blood transfusion, and immediate selective renal artery embolization (SAE). Four days after SAE, they offered her a successful PN to avoid any future bleeding attack.[8] Since preservation of postoperative renal function is one of the main goals to achieve during the treatment of giant AMLs, PN should be an option whenever it is possible. More recently, Zhou et al. have treated a 50-year-old female patient with bilateral AMLs (the right mass size was 28 cm, and the left mass size was 12 cm), with right radical nephrectomy and left SAE followed by PN after reduction of the tumor size.[6] From our review, it seems that recurrence after surgical treatment of AMLs (>20 cm) are uncommon, and all patients were tumor-free at their last follow-up.

In summary, giant AMLs are extremely rare condition that occurs sporadic or in association with TSC. Female hormones might cause a marked increase in its size and subsequent bleeding risk. Patients usually symptomatic and have large abdominal mass-related symptoms. CT scan is diagnostic in majority of cases due to its fat attenuation effect. Treatments of those giant masses include different treatment modalities such as active surveillance, SAE, PN, and radical nephrectomy according to the clinical scenario.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

   References Top

Nelson CP, Sanda MG. Contemporary diagnosis and management of renal angiomyolipoma. J Urol 2002;168:1315-25.  Back to cited text no. 1
Menany M, Khnaba S, Radouane B, Jidal M, Amil T, Saouab R. Giant bilateral angiomyolipomas with spontaneous hemorrhage and inferior vena cava thrombosis in a patient with tuberous sclerosis. Pan Afr Med J 2017;27:223.  Back to cited text no. 2
Nepple KG, Bockholt NA, Dahmoush L, Williams RD. Giant renal angiomyolipoma without fat density on CT scan: Case report and review of the literature. ScientificWorldJournal 2010;10:1334-8.  Back to cited text no. 3
Taneja R, Singh DV. Giant renal angiomyolipoma: Unusual cause of huge abdominal mass. J Clin Imaging Sci 2013;3:56.  Back to cited text no. 4
[PUBMED]  [Full text]  
Cavicchioli FM, D'Elia C, Cerruto MA, Artibani W. Giant bilateral renal angiomyolipomas: A case report. Urol Int 2014;92:366-8.  Back to cited text no. 5
Zhou Y, Tang Y, Tang J, Deng F, Gan YU, Dai Y. Total nephrectomy with nephron-sparing surgery for a giant bilateral renal angiomyolipoma: A case report. Oncol Lett 2015;10:2450-2.  Back to cited text no. 6
Kori C, Akhtar N, Vamsidhar PN, Gupta S, Kumar V. Giant exophytic renal angiomyolipoma mimicking as retroperitoneal sarcoma; a case report with review of literature. J Clin Diagn Res 2015;9:XJ01-2.  Back to cited text no. 7
Albersheim-Carter J, Klein M, Murugan P, Weight CJ. Partial nephrectomy for a massive sporadic renal angiomyolipoma: Case report and review of the literature. Case Rep Urol 2016;3420741:1-5.   Back to cited text no. 8
Chen P, Jin L, Yang Y, Chen Z, Ni L, Yang S, et al. Giant renal angiomyolipoma: A case report. Mol Clin Oncol 2017;7:298-300.  Back to cited text no. 9
Sharma G, Jain A, Sharma P, Sharma S, Rathi V, Garg PK. Giant exophytic renal angiomyolipoma masquerading as a retroperitoneal liposarcoma: A case report and review of literature. World J Clin Oncol 2018;9:162-6.  Back to cited text no. 10
Lee JD, Chang HC, Chu SH, Hsueh S, Soong YK. Massive retroperitoneal hemorrhage from spontaneous rupture of a renal angiomyolipoma during pregnancy. A case report. J Reprod Med 1994;39:477-80.  Back to cited text no. 11
Gould Rothberg BE, Grooms MC, Dharnidharka VR. Rapid growth of a kidney angiomyolipoma after initiation of oral contraceptive therapy. Obstet Gynecol 2006;108:734-6.  Back to cited text no. 12
Watanabe EH, Neves PD, Balbo BE, Sampaio CA, Onuchic LF. Giant renal angiomyolipoma following ovarian stimulation therapy. Urology 2018;112:e3-4.  Back to cited text no. 13
Wang L, Ni D, Zhong L, Wang J. Familial genetic tuberous sclerosis complex associated with bilateral giant renal angiomyolipoma: A case report. Oncol Lett 2017;14:7099-106.  Back to cited text no. 14
Kumar S, Modi P. Tuberous sclerosis with bilateral giant renal angiomyolipomas. Indian J Med Res 2016;143:667-8.  Back to cited text no. 15
[PUBMED]  [Full text]  
Simmons JL, Hussain SA, Riley P, Wallace DM. Management of renal angiomyolipoma in patients with tuberous sclerosis complex. Oncol Rep 2003;10:237-41.  Back to cited text no. 16


  [Figure 1], [Figure 2], [Figure 3], [Figure 4]

  [Table 1]


    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

  In this article
   Case Report
    Article Figures
    Article Tables

 Article Access Statistics
    PDF Downloaded235    
    Comments [Add]    

Recommend this journal