Prophylactic renal artery embolization before pregnancy in patients with lymphangioleiomyomatosis and renal angiomyolipoma.

OBJECTIVE: Pregnant patients with lymphangioleiomyomatosis (LAM) and renal angiomyolipomas (AMLs) require care for both renal AMLs and pulmonary dysfunction because AMLs can grow and rupture during pregnancy, potentially causing hemorrhagic shock and fetal death. This study examined whether prophylactic transcatheter arterial embolization (TAE) could prevent the pregnancy-associated growth and rupture of renal AMLs in patients with LAM. METHODS: This retrospective study included five women with 14 renal AMLs (initial diameter, ≥2 cm) first encountered between September 2010 and August 2015 who subsequently became pregnant. Seven tumors in five patients were embolized, and seven tumors in two patients were not treated. Changes in the volume of each tumor were evaluated. RESULTS: Untreated tumors were much more likely to grow than embolized tumors both during pregnancy (100% vs. 0%) and at the first follow-up visit after delivery (100% vs. 14%). One untreated hypervascular tumor grew rapidly during pregnancy to 409% of the pretreatment volume. No tumor ruptured. CONCLUSIONS: Prophylactic pre-pregnancy TAE decreased the growth and bleeding of renal AMLs during pregnancy in patients with LAM. TAE can be recommended for hypervascular tumors before pregnancy regardless of the size of the aneurysm.

Varying Outcomes among Patients with Large Angiomyolipomas according to the Treatment Method.

PURPOSE: This study aimed to evaluate the outcomes of large angiomyolipoma (AML) treatment by selective arterial embolization (SAE) versus nephron-sparing surgery (NSS) using a robotic surgical system. MATERIALS AND METHODS: Between January 2011 and June 2018, we retrospectively reviewed 25 patients who underwent robot-assisted partial nephrectomy (RAPN) or SAE for large AMLs. Ten patients underwent RAPN, and 15 underwent SAE. Patient demographics, AML characteristics, and operative and postoperative clinical outcomes were recorded and analyzed. Outcomes were compared between patients who underwent RAPN and patients who underwent SAE. Specifically, changes in renal function and size were evaluated after the treatment. RESULTS: The mean age of the patients was 52.9 years, and 22 of 25 patients were female. The mean maximum AML diameter on computed tomography was 8.9 cm, and 8 patients had multiple masses. Twenty-two of 25 patients had moderate to high RENAL complexity. Patients who underwent SAE had more symptoms (p = 0.018) and higher RENAL complexity scores (p = 0.013) on average. On average, tumor size decreased by 99% among RAPN patients and by 58% among SAE patients (p = 0.001). Although the mean pretreatment estimated glomerular filtration rate (eGFR) was higher among RAPN patients (99.8 vs. 80.0 mL/min/1.73 m2, p = 0.043), there were no significant changes in eGFR in either group after the treatment. One patient in the RAPN group experienced complications, but the postoperative ileus resolved without intervention. CONCLUSIONS: Both RAPN and SAE were effective and feasible treatment options for large AMLs. The AML characteristics and the condition of the patient might be important in determining the appropriate treatment method.

Differentiation between fat-poor angiomyolipoma and clear cell renal cell carcinoma: qualitative and quantitative analysis using arterial spin labeling MR imaging.

PURPOSE: To assess the diagnostic effectiveness of arterial spin labeling (ASL) MR imaging in differentiating fat-poor AML from clear cell renal cell carcinoma (ccRCC). METHODS: In this prospective study, 29 ccRCC patients and 9 fat-poor AML patients underwent routine anatomical MRI and ASL at 3T before surgery after signing written informed consent form. For each tumor, tumor blood flow (TBF) was measured in a region of interest (ROI) which was positioned to outline the edge of the target lesions on ASL perfusion maps. Additionally, the mean TBF values were obtained by standardizing the TBF using a blood flow measurement in the reference ROI. Moreover, a cluster containing more than 10 voxels was chosen from the renal cortex and medulla area in normal contralateral kidney as a reference ROI to calculate tumor-to-cortex ratio and tumor-to-medulla ratio. Independent sample t test was used to examine the alteration among the groups of fat-poor AML and ccRCC. ASL images were together analyzed by two radiologists to assess the following characteristics of the renal mass: predominant SI in the tumor on ASL images was lower than, as same as, or higher than SI of the cortex. For qualitative variables, Fisher's exact test was employed to compare the proportions of these two groups. The sensitivity, specificity ,and accuracy required for discrimination of fat-poor AML from ccRCC were quantified using receiver operating characteristic (ROC) curve. The corresponding optimal cutoff value was obtained for each parameter as well. RESULTS: The TBF value was significantly higher in ccRCC group than that in fat-poor AML (270.49 ± 78.88 ml/100 g/min vs. 146.68 ± 47.21 ml/100 g/min; P < 0.01). Both tumor-to-cortex and tumor-to-medulla ratios were notably higher in ccRCC group compared with those in fat-poor AML group (1.22 ± 0.26 vs. 0.74 ± 0.14, 3.13 ± 0.94 vs. 1.77 ± 0.55; P < 0.05). The values of area under the ROC curve (AUC) for TBF, tumor-to-cortex ratio, and tumor-to-medulla ratio were 0.931, 0.964, and 0.900, respectively. No significant difference in AUC values among these three measurements was observed. For qualitative variables, the SI of fat-poor AML was equal to or slightly lower than that of renal medulla and the SI of ccRCC was found to be higher than renal cortex in ASL. CONCLUSION: ASL MRI performs well in differentiating fat-poor AML from ccRCC in both qualitative and quantitative analyses.

Hepatic angiomyolipoma with early drainage veins into the hepatic and portal vein.

Hepatic angiomyolipoma (AML) is a rare stromal tumor composed of variable admixtures of thick-walled vessels, smooth muscles and adipose tissue. One of the specific radiological findings of hepatic AML is an early drainage vein noted via enhanced computed tomography (CT). We report a case of hepatic AML showing early drainage veins into both the hepatic and portal vein. The case involved a 46-year-old woman who was referred to our hospital because of a giant hepatic tumor. CT revealed well-enhanced 14 cm and 1 cm tumors in the left and right lobes, respectively. Magnetic resonance imaging demonstrated the existence of adipose tissues in the larger tumor. Hepatic arteriography revealed early drainage veins draining into both the hepatic and portal vein. Based on a diagnosis of hepatic AML, left hepatectomy and partial hepatectomy were performed. Pathology revealed both tumors as hepatic AML based on human melanoma black-45 immuno-positivity. Hepatic AML with early drainage veins into both the hepatic and portal vein is rare. The dilated and retrogressive vein drains the abundant arterial blood flow of the tumor. The finding of early drainage veins into not only the hepatic vein but also the portal vein should be helpful for diagnosing hepatic AMLs.

[A Case of Bilateral Angiomyolipoma Accompanied by Tuberous Sclerosis Complex Successfully Treated with Transcatheter Arterial Embolization Using Functional Kidney Mapping Images Consisting of SPECT-CT and Contrast Enhanced CT Images].

Renal angiomyolipoma (AML) and aneurysm are common in tuberous sclerosis complex (TSC) and represent the main causes of morbidity in adults with TSC. Herein, we report a 22-year-old woman with TSC-associated AMLs and renal aneurysms. She was referred to our hospital for the treatment of multiple renal aneurysms larger than 5 mm in diameter. The previous hospital considered that transcatheter arterial embolization (TAE) of bilateral renal aneurysms would cause deterioration of renal function. To estimate the impact of TAE on renal function, we superimposed contrast enhanced computed tomography (CT) over single-photon emission CT (SPECT)-CT. This fusion image, referred to as functional kidney mapping image, revealed the location of renal arteries and aneurysms, and normal renal parenchyma simultaneously. Functional kidney mapping image was useful to distinguish the AML region from the normal renal parenchyma, and revealed that the planned embolization site was a non-functioning parenchyma. Therefore, TAE for her multiple renal aneurysms was successfully performed without deterioration of her renal function.

Tumoral vascular pattern in renal cell carcinoma and fat-poor renal angiomyolipoma as a novel helpful differentiating factor on contrast-enhanced CT scan.

Our objective was to evaluate the differences between tumoral vascular pattern of renal cell carcinoma and fat-poor angiomyolipoma by contrast-enhanced computed tomography. All included patients had a definitive pathological diagnosis of either angiomyolipoma or renal cell carcinoma, and then the contrast-enhanced computed tomography images of these patients were evaluated. The patients who had visible prominent vessels in cross-sectional imaging were selected. The tumor vascular pattern (prominent (>2 mm) intratumoral and peritumoral vessels), density, and diameter of the vessels in renal cell carcinoma and fat-poor angiomyolipoma were evaluated. All cases (n = 12) with fat-poor angiomyolipoma were found to have intratumoral vessels and all cases (n = 36) with clear cell renal cell carcinoma were found to have peritumoral vessels. There was no significant correlation detected between the diameter of tumor and the density as well as diameter of the vessels. In conclusion, the evaluation of the vascular pattern using contrast enhancement contrast-enhanced computed tomography may provide important information that is useful in helping accurate differential diagnosis of fat-poor angiomyolipoma or renal cell carcinoma preoperatively.

Super-Selective Artery Embolization before Laparoscopic Partial Nephrectomy in Treating Renal Angiomyolipoma.

INTRODUCTION: To investigate the feasibility and efficiency of super-selective artery embolization (SAE) before laparoscopic partial nephrectomy (LPN) in treating renal angiomyolipoma (RAML). MATERIALS AND METHODS: A retrospective analysis was conducted on 36 consecutive patients who underwent SAE before LPN (group A, n = 16) or LPN directly (group B, n = 20) from June 2010 to March 2016. Intraoperative blood loss, blood transfusion, operation time, warm ischemia time (WIT), and prognosis were compared between groups. RESULTS: SAE before LPN decreased operating time, intraoperative blood loss and WIT (p < 0.05), and improved postoperative renal function (p < 0.001). Complications in group B included intraoperative blood loss of 4 patients and postoperative hematuria of 2 patients who recovered a few days later. No complications were observed in group A. In the follow-up of 3 months, a patient in group B formatted retroperitoneal hematoma without any symptoms and received expectant treatment. CONCLUSIONS: The application of SAE before LPN can decrease the difficulty of the surgery, the complications, and the risk of rebleeding and RAMLs recurrence.

Transarterial embolization for renal angiomyolipomas: A single centre experience in 79 patients.

Objective To evaluate the long-term efficacy and safety of selective arterial embolization (SAE) in the treatment of renal angiomyolipomas (AMLs). Methods This was a retrospective review of medical records and imaging findings from patients with renal AMLs who attended our clinic and received SAE between January 2007 and January 2014. Only patents with complete medical records, preoperative computed tomography scans using typical imaging and follow-up data were included. Results A total of 79 patients were enrolled in the study. Technical and clinical success rates were 100% and 91% ( n = 72), respectively. Only two patients experienced major complications. Post-embolization syndrome (i.e. fever, abdominal pain, nausea or vomiting) was reported in 68 (86%) patients, but all symptoms were mild and resolved with conservative measures. Mean radiological and clinical follow-up periods were 16.8 and 35.9 months, respectively. In 75 (95%) patients, tumours decreased in size; mean ± SD tumour size significantly decreased from 8.4 ± 3.5 cm pre-embolization to 6.7 ± 3.0 cm post-embolization . Conclusions This study provides long-term evidence that SAE is a safe and effective method in the treatment of patients with renal AMLs.

Spontaneous rupture of renal angiomyolipoma during pregnancy.

A renal angiomyolipoma (AML) is a rare benign tumour of kidney origin. Pregnancy is known to be associated with an increased risk of tumour rupture causing hypovolaemic shock, which is usually managed surgically or through an embolisation procedure. However, having surgery during pregnancy predisposes the mother to a preterm delivery, and the unknown influences of radiation exposure to the fetus make the management of such cases very challenging. A 30-year-old pregnant woman had a sudden onset of gross haematuria at the 20th week of her pregnancy. The MRI showed a 10 cm mass suggestive of AML in the left kidney, with evidence of an intrarenal haematoma. To avoid an iatrogenic preterm delivery and unnecessary fetal exposure to radiation, conservative management was conducted until 34 weeks of gestation, when she came to our hospital reporting of flank pain. An endovascular treatment was performed immediately after an emergency caesarean delivery.

CD68-Positive Cells in Hepatic Angiomyolipoma.

Four resected specimens of hepatic angiomyolipoma in which uptake of Sonazoid was observed in the postvascular phase of Sonazoid-enhanced ultrasonography were analyzed. Macrophage localization in the tumor was revealed pathologically by immunohistochemical staining for CD68. CD68-positive cells were observed in the tumor in all cases. The density of CD68-positive cells was 100/mm2, and the ratio of CD68-positive cell density in the tumor to that in the surrounding parenchyma was 32-171%. These results suggested that the uptake of the contrast agent Sonazoid was related to the density of CD68-positive cells.

Arterial Embolization for the Treatment of Renal Masses and Traumatic Renal Injuries.

Renal artery embolization (RAE) for a variety of indications has been performed for several decades. RAE techniques have been refined over time for clinical efficacy and a more favorable safety profile. Owing to improved catheters, embolic agents for precise delivery, and clinical experience, RAE is increasingly used as an adjunct to, or as the preferred alternative to surgical interventions. The indications for RAE are expanding for many urologic and medical conditions. In this article, we focus on the role and technical aspects of RAE in the treatment of renal masses and traumatic renal injuries.

Microaneurysms in renal angiomyolipomas: Can clinical and computed tomography features predict their presence and size?

PURPOSE: To evaluate clinical and multidetector computed tomography (MDCT) features associated with the presence and size of microaneurysms in renal angiomyolipomas (AMLs). MATERIALS AND METHODS: The MDCTs and digital subtraction angiographies (DSAs) of 31 patients who had further percutaneous arterial embolization of AMLs were retrospectively reviewed. They were 22 women and 9 men (mean age, 47.7±27.7 years). The medical files of the included patients were reviewed for age, gender and clinical features. MDCT and DSA images were analyzed by two readers working in consensus. RESULTS: Of the 31 patients, 15 had tuberous sclerosis complex (TSC) or lymphangioleiomyomatosis (LAM). In total, the 31 patients had 54 AMLs (5 ruptured). On DSA, 28 clusters of microaneurysms were found in 17 patients (21 AMLs). Four of the five ruptured AMLs had microaneurysms. None of the 12 AMLs≤40mm and 21 of the 42 AMLs>40mm had microaneurysms. Among AMLs>40mm, history of TSC/LAM (P=0.5), RENAL score (P=0.7) and relative volume of fat (P=0.11) did not significantly predict the presence of microaneurysms. Microaneurysms were significantly larger in ruptured (9.5±5.7mm) than non-ruptured (3.9±1.9mm, P=0.02) AMLs. No associations were found between the size of microaneurysms and the size of AMLs. CONCLUSION: Microaneurysms were found in no AML ≤40mm and in 50%of AMLs>40mm. In AMLs >40mm, history of TSC/LAM, RENAL score and relative volume of fat did not significantly predict the presence of microaneurysms.

Multidetector Computed Tomography Features in Differentiating Exophytic Renal Angiomyolipoma from Retroperitoneal Liposarcoma: A Strobe-Compliant Observational Study.

This study aims to evaluate the multidetector computed tomography (CT) imaging features in differentiating exophytic renal angiomyolipoma (AML) from retroperitoneal liposarcoma. We retrospectively enrolled 42 patients with confirmed exophytic renal AML (31 patients) or retroperitoneal liposarcoma (11 patients) during 8 years period to assess: renal parenchymal defect at site of tumor contact, supply from branches of renal artery, tumoral vessel extending through the renal parenchyma, dilated intratumoral vessels, hemorrhage, non-fat-containing intratumoral nodules with postcontrast enhancement, calcification, renal sinus enlargement, anterior displacement of kidneys, and other associated AML. Renal parenchymal defect, renal arterial blood supply, tumoral vessel through the renal parenchyma, dilated intratumoral vessels, intratumoral/perirenal hemorrhage, renal sinus enlargement, and associated AML were seen only or mainly in exophytic renal AML (all P value < 0.05); however, non-fat-attenuating enhancing intratumoral nodules, intratumoral calcification, and anterior displacement of the kidney were more common in liposarcoma (all P value < 0.05). AMLs reveal renal parenchymal defect at the site of tumor contact, supply from renal artery, tumoral vessel extending through the renal parenchyma, dilated intratumoral vessels, intratumoral and/or perirenal hemorrhage, renal sinus enlargement, and associated AML. Non-fat-attenuating enhancing intratumoral nodules, intratumoral calcifications, and anterior displacement of kidney were more commonly seen in liposarcoma.

[Epithelioid Angiomyolipoma of the Kidney: A Case Report].

Herein we report a case of epithelioid angiomyolipoma of the kidney which is a rare subtype of angiomyolipoma. A 68-year-old man without a history of tuberous sclerosis complex (TSC) was referred to our department with a 40 × 84 mm left renal tumor incidentally detected by computed tomography. Computed tomography demonstrated a left renal heterogeneous mass which was enhanced at the early phase and washed out at the late phase. A tumor thrombus was seen extending into the main renal vein. No metastatic disease was evident. Thus, on the diagnosis of renal cell carcinoma, the patient underwent a left radical nephrectomy. Pathological examination showed that this tumor was composed predominantly of epithelioid cells, with a few blood vessels and adipose tissue and was diagnosed as epithelioid angiomyolipoma. He shows no disease progression for 6 months after the operation.

Study of 320-slice dynamic volume CT perfusion in different pathologic types of kidney tumor: preliminary results.

OBJECTIVE: To investigate microcirculatory differences between pathologic types of kidney tumor using 320-slice dynamic volume CT perfusion. METHODS: Perfusion imaging with 320-slice dynamic volume CT was prospectively performed in 85 patients with pathologically proven clear cell renal cell carcinoma (RCC) (n = 66), papillary RCC (n = 7), chromophobe RCC (n = 5), angiomyolipoma (AML) with minimal fat (n = 7), or RCC (n = 78). Equivalent blood volume (Equiv BV), permeability surface-area product (PS; clearance/unit volume = permeability), and blood flow (BF) of tumor and normal renal cortex were measured and analyzed. Effective radiation dose was calculated. RESULTS: There was a significant difference in all three parameters between tumor and normal renal cortex (P<0.001). Equiv BV was significantly different between RCC and AML with minimal fat (P = 0.038) and between clear cell RCC and AML with minimal fat (P<0.001). Mean Equiv BV and BF were significantly higher in clear cell RCC than in papillary RCC (P<0.001 for both) and mean Equiv BV was higher in clear cell RCC than in chromophobe RCC (P<0.001). The effective radiation dose of the CT perfusion protocol was 18.5 mSv. CONCLUSION: Perfusion imaging using 320-slice dynamic volume CT can be used to evaluate hemodynamic features of the whole kidney and kidney tumors, which may be useful in the differential diagnosis of these four pathologic types of kidney tumor.

Development of multiple focal nodular hyperplasia lesions after portocaval shunting. A case report.

It has been postulated that altered hepatic blood flow, particularly reduced portal flow, is responsible for the induction of hyperplasia of liver cells and nodule formation. This report describes the case of a 31-year old female patient developing multiple focal nodular hyperplasia (FNH) lesions two years after portocaval shunting and extended right hemihepatectomy due to the suspicion of a malignant liver tumor. Portocaval shunting became necessary due to iatrogenic thrombosis of the entire portal vein after preoperative embolization of the right portal vein. This observation provides for the first time direct evidence for the pathogenesis of FNH in humans.

Hepatic epithelioid angiomyolipoma with arterioportal venous shunting mimicking hepatocellular carcinoma: report of a case.

A patient with hepatic epithelioid angiomyolipoma (Epi-AML) with arterioportal venous shunting, who was successfully treated by a laparoscopic left lateral sectionectomy, is presented herein. AML is an uncommon benign neoplasm of the liver. Tumors composed predominantly of epithelioid cells have been subcategorized into Epi-AML, and the treatment strategy for Epi-AML is currently undetermined. There are no reports describing Epi-AML with arterioportal venous shunting to date. An arterioportal venous shunting of the liver tumor was suggested to be one of the malignant signs of the liver tumor. It would be important to differentiate Epi-AML with arterioportal venous shunting from hepatocellular carcinoma and hypervascular metastatic tumors. Minimally invasive resection, such as laparoscopic hepatectomy, for patients having Epi-AML with arterioportal venous shunting may be recommended.

Angiomyolipoma of the liver: a reappraisal of morphological features and delineation of new characteristic histological features from the clinicopathological findings of 55 tumours in 47 patients.

AIMS: The aim of this study was to characterize and delineate the broad histological spectrum of hepatic angiomyolipoma (AML) and to obtain a better understanding of its clinicopathological diagnosis by reviewing a large series of AMLs. METHODS AND RESULTS: According to the proportions of three histological components, AML could be classified into 10 types; 36 of 55 tumours (65%) were classified as myomatous, eight as myoangiomatous, six as mixed (conventional), two as lipomatous, two as myolipomatous, and one as lipomyomatous. The morphology of smooth muscle cells (SMCs) in AML was quite variable, giving a wide variety of growth patterns. Fourteen (25%) of 55 tumours showed severe cellular atypia, and invasive growth of tumour cells was found in 69% of the tumours. However, except for two autopsy cases, all of the patients were in good health at follow-up, without metastases. Immunostaining for HMB-45 was positive in all cases. We found frequent lymphocyte infiltration, and the occasional presence of abnormally large blood vessels around the tumour at the tumour-background liver interface, features which have not been reported previously. CONCLUSIONS: The majority of hepatic AMLs were myomatous in type, showing variable cellular morphology and growth patterns. Cellular atypia and invasive growth were frequent, indicating that hepatic AMLs often show malignancy-like histological features. Although the majority of cases behave as benign tumours, AML should be considered to have uncertain malignant potential, and careful follow-up of patients is recommended. Immunostaining for HMB-45 is specific for AML, and establishes the diagnosis. The occasional presence of abnormally large blood vessels around the tumour may give new insights into the evaluation of findings from imaging.

Pelvic angiomyolipoma.

Angiomyolipoma is a rare benign tumor most commonly found in the kidney and, infrequently, extrarenally. We report a case of pelvic angiomyolipoma in a male patient without stigmata of tuberous sclerosis. The patient presented with right retroperitoneal bleeding and was found to have bilateral renal angiomyolipomas as well as a pelvic mass with similar appearance as the other lesions. He underwent urgent embolization of the large right angiomyolipoma and subsequent robot-assisted left laparoscopic partial nephrectomy with simultaneous resection of the pelvic mass, which was well-tolerated. Pathology confirmed what is, to our knowledge, the only reported case of pelvic angiomyolipoma.