A Life-threatening Case of Giant Bilateral Renal Angiomyolipoma: A Case Report

Renal angiomyolipoma (AML) is a rare tumor with an incidence of 0.3% - 3%.

We reported a case of a 41-year-old male patient who presented with gross hematuria and hemorrhagic shock, due to a right giant angiomyolipoma he underwent urgent right nephrectomy by subcostal laparotomy, total weight of the mass was 6 Kg, histological examination concluded in a renal angiomyolipoma.

Treatment of renal AML depends on the clinical presentation, tumor size, and single or multiple lesions: single small (< 4 cm) asymptomatic lesions require only clinical and radiological follow-up, however giant symptomatic (hematuria), life-threatening masses require urgent multidisciplinary treatment and especially surgery.

Giant renal bilateral AML is very rare, conservative treatment in the absence of hemorrhage should always be first proposed to preserve renal function as possible.

Renal Angiomyolipoma (AML) is a rare tumor with an incidence of 0.3% - 3% [1]. Some 80% of renal angiomyolipomas are sporadic and the remaining 20% are associated with tuberous sclerosis complex [2].

It is the most common benign renal tumor and is defined by its 3 histological components: blood vessels, smooth muscle, and adipose tissue [3]. Giant AMLs associated with Tuberous Sclerosis Complex (TSC) represent a treatment challenge and are life-threatening [3].

We reported a case of a 41-year-old male patient with TSC and epilepsy, suffering from chronic right lower back pain, who presented with gross hematuria and hemorrhagic shock. After stabilization with vasoactive drugs and a massive transfusion of red blood cell units, a CT scan showed bilateral giant renal AMLs, a right renal hematoma of 4cm, and multiple intra-tumoral aneurysms (Figure 1). Hemodynamic status was stable, hemoglobin level was 7 g/dl. The patient was admitted to the intensive care unit of the urology department and blood pressure, pulse, and hemoglobin levels were monitored. On the next day of hospitalization, the haemoglobin level dropped to 5 g/dl with hypotension and tachycardia.

Angioembolization was not available because of the lack of a coil so an urgent right nephrectomy by subcostal laparotomy was performed. Intraoperative blood loss needed a transfusion of 3 red blood cell units.

The total weight of the mass was 6 kg (Figure 2).

The postoperative course was normal, the patient left the intensive care department after 3 days and the hospital after 7 days.

A histological examination of the mass revealed an angiomyolipoma (Figure 3).

The follow-up over 2 years showed stability of the left angiomyolipoma on ultrasound and did not show any recurrence of hematuria.

Affecting generally middle-aged women with an incidence of 0.3% in the normal population [4], AMLs of the kidneys remain usually asymptomatic, and symptoms like gross hematuria, and low back pain usually reveal masses > 4 cm.

Three types of AML were described in the literature: Sporadic, associated with tuberous sclerosis complex which is the case of our patient, and those that are associated with lung lymphangioleiomyomatosis (LAM) [4].

Some 80% of renal angiomyolipomas are sporadic and the remaining 20% are associated with tuberous sclerosis complex [2].

AML is the only benign renal tumor that can be diagnosed by CT scan: The presence of fat, confirmed by a negative attenuation value of -25 HU or less in CT, within a renal lesion is considered the diagnostic hallmark [5].

AMLs associated with TSC have generally bigger sizes and so more symptomatic than sporadic ones.

Treatment of renal AML depends on the clinical presentation, tumor size, and single or multiple lesions: single small (< 4 cm) asymptomatic lesions require only clinical and radiological follow-up, however giant symptomatic (hematuria), life-threatening masses require urgent multidisciplinary treatment and especially surgery [6].

Bilateral giant AML which is a benign lesion poses a therapeutic challenge: treatment principles are the resolution of symptoms and prevention of complications such as hemorrhage without comprising renal function.

These principles can be more and more respected due to the development of radiologic embolization and the ability of surgeons to perform partial nephrectomy [6].

Giant renal bilateral AML is very rare, conservative treatment in the absence of hemorrhage should always be first proposed to preserve renal function as possible.

Statement of ethics

Ethical approval is not required for this study in accordance with local or national guidelines.

Written informed consent was obtained from the patient for publication of the details of his medical case and any accompanying images.

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

We are grateful to all the staff of the Urology and Pathology Department of our hospital who contributed to this project.

Methods

The work has been reported in line with the SCARE criteria.

Agha RA, Franchi T, Sohrab C, Mathew G, Kirwan A, Thomas A, et al. The SCARE 2020 guideline:

Updating consensus Surgical Case Report (SCARE) guidelines. International Journal of Surgery. 2020; 84(1):226-30.

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