Diagnosis Of Renal Angiomyolipoma Research Articles

Hemorrhagic renal angiomyolipoma: An analysis of 6 cases with review of the literature

Renal angiomyolipoma is the most common benign solid tumor of the kidney. It can occur sporadically or in association with tuberous sclerosis, which is an autosomal dominant inherited disease. Hemorrhagic rupture of renal angiomyolipoma with retroperitoneal hematoma is the most serious complication that can be life-threatening and requires urgent management. The aim of this study is to review, through 6 cases and by means of a review of the literature, the diagnostic criteria of renal angiomyolipoma and the particularities of management of hemorrhagic renal angiomyolipoma. We carried out a retrospective study which concerned 6 patients with hemorrhagic renal angiomyolipoma, unilateral or bilateral, during the period between January 2019 and August 2021, in the Urology Department of the Hassan II University Hospital in Fez. The average age of our patients was 53 years with an F/M sex ratio of 2. Bourneville's tuberous sclerosis was diagnosed in 3 patients. The circumstances of discovery of renal angiomyolipoma were: acute flank pain associated with anemic syndrome in 3 patients, incidental discovery in 1 patient, clot hematuria in 1 patient and abdominal mass in 1 patient. Clinical examination revealed hemodynamic instability in 1 patient, flank defense in 2 patients, lumbar mass in 1 patient and lumbar tenderness in 1 patient. The abdominal CT angiogram allowed us to retain the diagnosis of renal angiomyolipoma in all the patients, with a bilateral form in the 3 patients with tuberous sclerosis of Bourneville. Renal embolization was performed in 5 patients, while total nephrectomy was performed in 1 patient. Renal angiomyolipoma is a rare tumor in daily urological practice. Its hemorrhagic risk requires a good knowledge of diagnostic, therapeutic and monitoring methods.

СОПОСТАВЛЕНИЕ РЕЗУЛЬТАТОВ УЗИ, КТ И МРТ ПРИ ДИАГНОСТИКЕ АНГИОМИОЛИПОМЫ ПОЧКИ, В ТОМ ЧИСЛЕ ОСЛОЖНИВШЕЙСЯ РАЗВИТИЕМ СИНДРОМА ВУНДЕРЛИХА

Purpose: Analysis the effectiveness of various methods of radiation studies for the detection of renal angiomyolipomas (RAMLs), including the diagnosis of Wunderlich syndrome.
 Material and methods: The analysis of the results of a comprehensive radiation study of the kidneys of 115 patients who were diagnosed with focal formation in primary renal ultrasound was carried out. Further, of those 115 people, 47 patients underwent MRI of the kidneys, 60 patients – CT and 8 patients complex MRI+CT, including contrast-enhanced vasculature.
 Results and discussion: Angiomyolipoma was detected by ultrasound in 38 (33.0 %) of 115 patients, and according to MRI and CT in total in 27 (23.5 %) patients. Coincidence of ultrasound findings and MRI and CT results was in 18 patients. Consequently, the sensitivity of ultrasound in the diagnosis of RAML was compared with MRI – 45 %; when compared with CT – 42.8 %, and specificity – 55 % and 57.1 %, respectively. Reliable signs of RAML in ultrasound were hyperechogenic homogeneous structure, clear smooth contours of the formation. The rounded form of education is statistically unreliable. Statistically significant characteristics of RAML in magnetic resonance imaging are heterogeneous structure, heterogeneous hyperintense MR-signal on T1 and heterogeneously hypointensity on T2-weighted images, always uniformly hypo-Fs for T1 / T2 Fs, with hypo clear boundary between education and renal parenchyma on T1 in the opp phase. Reliable signs of RAML with CT are non-uniform structure of education, with non-uniform x-ray density. 
 Conclusion: Ultrasound diagnosis is necessary for screening kidney disease, while CT and MRI have greater sensitivity and specificity to determine the nature of focal formation. With the development of Wunderlich’s syndrome, a complex of radiological methods, including ultrasound, MRI and CT, allows to diagnose the cause of hemorrhage, as well as to obtain complete diagnostic information necessary for the surgeon to plan treatment.

Enhancing disease awareness for tuberous sclerosis complex in patients with radiologic diagnosis of renal angiomyolipoma: an observational study

BackgroundTuberous Sclerosis Complex (TSC) is a genetic disorder, with renal manifestations like angiomyolipoma (AML) occurring in 70–80% of patients. AML usually cause more complications in TCS patients than in non-TSC patients. However, AML patients are not routinely investigated for TSC. Our aim was to retrospectively assess the correlation between radiologically diagnosed AML and TSC.MethodsAll patients were stratified into AML related vs. unrelated to TSC. Correlations were calculated to determine the association between age, AML, and TSC.ResultsComplete data were available for 521 patients with renal AML, in 7 of which the concurrent diagnosis of TSC was found. Younger age significantly positively correlated with the prevalence of TSC in AML patients (p < 0.01). 37 (7%) of the 521 patients were within the age-range of 18–40 years, in which TSC occurred in 6 cases, 4 (66.7%) of which presented with multiple, bilateral renal AML (p < 0.05), and 2 (33.3%) of which with a single, unilateral AML (p < 0.05). In patients with AML but without TSC, unilateral AML was found in 83.9% and bilateral AML in 16.1% (p < 0.05). Simple binary logistic regression analysis revealed bilateral AML (OR 33.0; 95% CI 3.2–344.0; p = 0.003) (but not unilateral AML (OR 0.09; 95% CI 0.01–0.88; p = 0.04)) to be a risk factor for TSC.ConclusionsThe presence of bilateral AML in patients within the age-range of 18–40 years should raise suspicion for TSC as the underlying cause. Therefore, our advice is to refer patients with multiple bilateral renal AML for further investigations regarding TSC.

Utility of material-specific fat images derived from rapid-kVp-switch dual-energy renal mass CT for diagnosis of renal angiomyolipoma.

Renal angiomyolipoma (AML) are benign masses that require detection of macroscopic fat for accurate diagnosis. To evaluate fat material-specific images derived from dual-energy computed tomography (DECT) to diagnose renal AML. This retrospective case-control study evaluated 25 renal AML and 44 solid renal masses (41 renal cell carcinomas, three other tumors) imaged with rapid-kVp-switch DECT (120 kVp non-contrast-enhanced [NECT], 70-keV corticomedullary [CM], and 120-kVp nephrographic [NG]-phase CECT) during 2017-2018. A radiologist measured attenuation (Hounsfield Units [HU]) on NECT, CM-CECT, NG-CECT, and fat concentration (mg/mL) using fat-water base-pair images. At NECT, 100% (44/44) non-AML and 4.0% (1/25) AML measured >-15 HU. At CM-CECT and NG-CECT, 24.0% (6/25) and 20.0% (5/25) AML measured >-15 HU (size 6-20 mm). To diagnose AML, area under receiver operating characteristic curve (AUC) using -15 HU was: 0.98 (95% confidence interval [CI] 0.98-1.00) NECT, 0.88 (95% CI 0.79-0.91) CM-CECT, and 0.90 (95% CI 0.82-0.98) NG-CECT. At DECT, fat concentration was higher in AML (163.7 ± 333.9 [-553.0 to 723.5] vs. -2858.1 ± 460.3 [-2421.2 to -206.0] mg/mL, P<0.001). AUC to diagnose AML using ≥-206.0 mg/mL threshold was 0.98 (95% CI 0.95-1.0) with sensitivity/specificity of 92.0%/96.7%. Of AML, 8.0% (2/25) were incorrectly classified; one of these was fat-poor. AUC was higher for fat concentration compared to HU measurements on CM-CECT and NG-CECT (P=0.009-0.050) and similar to NECT (P=0.98). DECT material-specific fat images can help confirm the presence of macroscopic fat in renal AML which may be useful to establish a diagnosis if unenhanced CT is unavailable.

Burden of renal angiomyolipomas associated with tuberous sclerosis complex: results of a patient and caregiver survey

BackgroundTuberous sclerosis complex (TSC) is a rare genetic disorder characterized by benign tumors in multiple organs, including non-cancerous kidney lesions known as renal angiomyolipomas. This study’s objective is to describe the age-stratified morbidity, treatment patterns, and health-related quality of life of TSC patients with renal angiomyolipomas in the United States. A cross-sectional, anonymous web-based survey was conducted with a convenience sample of TSC patients and caregivers identified through a patient advocacy organization.ResultsOut of the total sample of 676, 182 respondents reported having kidney complications with 33% of the pediatric group and 25% of the adult group with TSC reporting them. Of those with kidney complications, 110 (60%) reported a diagnosis of renal angiomyolipomas, of which 79 (72%) were adult patients and 31 (28%) were pediatric age patients. Eighty-four percent of the pediatric group and 76% of the adult group reported lesions on both kidneys. Of the patients experiencing involvement of only one kidney, 60% of the pediatric group and 21% of the adult group reported having multiple tumors within the affected kidney. Almost all of the sample (99%) reported seeing a physician and having a procedure or test for TSC in the past year. Less than half the respondents (44%) reported being hospitalized in the past year. Thirty-nine percent reported an emergency room visit as well. Compared to scores for patients with kidney disease, the angiomyolipoma adult patients reported significantly lower Mental Component Summary scores on the SF-12.ConclusionsRenal angiomyolipomas burden leads to frequent healthcare resource use including hospitalization, invasive treatments, and surgical procedures, which result in an impaired mental health related quality of life.

Diagnosis of Renal Angiomyolipomas: Classic, Fat-Poor, and Epithelioid Types

With the increasing discovery of small renal masses with cross-sectional imaging, there has been the concomitant rise in their treatment. With the intent of early curative surgery for a presumed renal cell carcinoma, many renal masses are being resected at surgery without a confirmed diagnosis. Many of them are benign, and some are angiomyolipomas. The diagnosis of renal angiomyolipoma using imaging is, therefore, is as important as ever. Although most, if not all angiomyolipomas with abundant fat are diagnosed readily, some have too little fat to be detected with imaging. This article reviews the current classification, imaging pitfalls, and diagnosis of angiomyolipoma with an emphasis on the fat-poor types. Proper imaging technique, a thorough search for fat, and the appropriate use of percutanoeus biopsy are all needed to eliminate the unnecessary treatment of these benign neoplasms.

Clinical presentation, management, and outcome of patients with incidental renal angiomyolipoma in qatar.

Our study aimed to analyze the clinical presentation, management, and outcome of renal angiomyolipoma patients incidentally detected upon computed tomography (CT) examination. Between 2004 and 2008, all patients who underwent abdominal CT examination for any reason at the radiology department at Hamad General Hospital, Qatar were retrospectively reviewed. The diagnosis of renal angiomyolipoma was based on abdominal CT evaluation. Angiomyolipoma patients were followed-up by CT evaluation as per standard care for three years to observe any change in size and outcome. A total of 13,115 patients were screened, of which 56 (40 females and 16 males) had renal angiomyolipoma. The mean age of patients was 52±13 years with 46% Qatar nationals. The majority (95%) of cases had unilateral tumors (52% right-sided and 43% left-sided). Twenty-six cases showed increase in tumor size and the median increase was 0.5cm (0.1-3.6). Surgical intervention was required in four (7%) cases with tumor size ≥4cm. The overall mortality on follow-up was 7%. The cause of death included metastasis, renal failure, hepatic failure and mesenteric thromboembolism. Renal angiomyolipoma is an uncommon benign tumor with an overall prevalence of 0.4% in Qatar. It has characteristic clinical features and its recognition is often challenging for proper clinical diagnosis and treatment in asymptomatic patients. Asymptomatic patients need regular radiological surveillance. In contrast, surgical interventions are mainly required in symptomatic patients with increased tumor size (≥4cm). Timely diagnosis and treatment is necessary to avoid complications such retroperitoneal hemorrhage and renal impairment.

Diagnosis of Renal Angiomyolipoma with CT Hounsfield Unit Thresholds

Diagnosis of Renal Angiomyolipoma with CT Hounsfield Unit Thresholds

Diagnosis of Renal Angiomyolipoma with Hounsfield Unit Thresholds: Effect of Size of Region of Interest and Nephrographic Phase Imaging

To retrospectively determine the optimal Hounsfield unit threshold and region of interest (ROI) size required to accurately diagnose renal angiomyolipoma (AML) and differentiate it from renal cell carcinoma (RCC). This retrospective study was institutional review board approved and HIPAA compliant, and the requirement for written informed patient consent was waived. The radiologic reports on 4502 dual-phase abdominal computed tomography (CT) examinations (nonenhanced and nephrographic phases, 5-mm collimation, 120-140 kVp, variable milliampere-second settings) performed in 2872 patients from June 2002 through October 2007 were reviewed. Solid-component masses reported as suspicious for RCC or AML were correlated with histologic and/or follow-up imaging findings. ROIs of three different sizes-tiny (8-13 mm(2)), small (19-24 mm(2)), and medium (30-35 mm(2))-were drawn in the lowest-attenuation focus on images obtained during both phases. The test characteristics (sensitivity, specificity, positive predictive value, negative predictive value, false-positive rate, false-negative rate) of multiple attenuation thresholds at each combination of ROI size and contrast enhancement phase were calculated, and receiver operating characteristic (ROC) curves were derived. Areas under the ROC curve were calculated. There were 217 RCCs and 65 AMLs. With an attenuation threshold of -10 HU or lower at nonenhanced CT, RCC would be misdiagnosed as AML in 11 (5.1%) cases, one (0.5%) case, and one (0.5%) case with use of the tiny, small, and medium ROIs, respectively. With use of the tiny, small, and medium ROIs, misdiagnosis rates would be 2.3%, 0.5%, and 0.5%, respectively, at a threshold of -15 HU or lower and 1.8%, 0%, and 0%, respectively, at a threshold of -20 HU or lower. Areas under the ROC curve for the nonenhanced phase images (range, 0.874-0.889) were superior to those for the nephrographic phase images (range, 0.790-0.826). Nonenhanced CT images were superior to nephrographic phase CT images for the diagnosis of AML. An attenuation threshold of -10 HU or lower with an ROI of at least 19-24 mm(2) is optimal for the diagnosis of AML. This threshold is not accurate with use of smaller (8-13-mm(2)) ROIs.

Wunderlich's syndrome in spontaneous angiomyolipoma bleeding.

A 57-year-old female presented to the emergency department with progressive right flank pain for 2 days. She denied recent traumatic events. Initial vital signs were stable with blood pressure 125/80 mmHg. Physical examination revealed right flank knocking tenderness. Laboratory data showed leukocytosis 20 180/μL and normal haemoglobin 10.5 g/dL. The routine urine analysis was normal. After clinical evaluation, an abdominal computer tomography (CT) revealed a huge fat-containing tumor with active contrast extravasation and hematoma formation over the right perirenal space (Figure 1A). A diagnosis of renal angiomyolipoma with spontaneous bleeding was made. Transarterial angiography of the right kidney was emergently performed with coil embolization of the hypervascular tumor with intralesional aneurysmal formations (Figure 1B). The patient’s symptoms resolved shortly after embolization and she was scheduled for further renal-sparing surgery. Fig. 1. Renal angiomyolipoma are generally benign mesenchymal hamartoma composed of adipose tissue, tortuous blood vessels and smooth muscle. About 80% of renal angiomyolipoma occurs sporadically and 20% associated with tuberous sclerosis complex [1, 2]. Sporadic angiomyolipoma usually with a solitary nodule in middle-aged women; tuberous sclerosis complex with angiomyolipoma are usually bilateral and multiple, frequently with larger tumor size [2]. Clinical presentations of angiomyolipoma are usually subclinical until tumor size becomes progressively larger with mass effect or tumor rupture. Wunderlich’s syndrome (spontaneous renal hemorrhage) is a rare but potentially life-threatening complication of renal angiomyolipoma in the setting of tumors >4 cm. Clinical manifestations usually include flank pain, a palpable mass, gross hematuria and hypovolemic shock. CT is a good choice of imaging modalities because it is sensitive to demonstrating a fat-containing renal mass with perirenal and retroperitoneal hemorrhage, which is characteristic of Wunderlich’s syndrome due to spontaneous angiomyolipoma rupture. In addition, intralesional aneurysmal formations on the CT scan can lead to a greater possibility of tumor rupture [3]. Optimal treatment plans of angiomyolipoma depend on the tumor size and clinical manifestations. Conservative follow-up with imaging modality is recommended if tumor size is <4 cm in diameter. In acute tumor rupture, urgent transarterial superselective embolization can stop bleeding and save the life of patient. In symptomatic or larger angiomyolipoma with a high risk of bleeding, optimal treatment including elective preoperative transarterial superselective embolization prevention of and sequential renal-sparing surgery [4].

An exceptional minute tumour incidentally found in a renal biopsy

Pathological analysis of renal biopsies performed to investigate a nephrological disease may exceptionally reveal incidental tumours, in addition to expected glomerular, tubulointerstitial or vascular pathology. We present the first case to date of a minute angiomyolipoma (AML), found incidentally in a renal biopsy specimen, performed in the assessment of proteinuria. AML is an uncommon kidney tumour, composed of a variable proportion of adipose tissue, spindle and epithelioid smooth muscle cells. Immunohistochemistry is mandatory for a definitive diagnosis, showing a specific perivascular epithelioid differentiation. The diagnosis of renal AML justifies the search for tuberous sclerosis-associated tumours.

Contemporary Experience in the Management of Angiomyolipoma

We review our single center experience in the management of renal angiomyolipoma (AML) in patients who were treated with active surveillance (AS) or invasive treatment protocols. A prospectively evaluated database was reviewed, and we identified 91 patients with the diagnosis of renal AML who presented between June 1985 and February 2009. Patient characteristics, clinical presentation, treatment modalities, and patient outcomes were evaluated. Patients on AS were analyzed for successful completion of the surveillance protocol considering age, symptomatic presentation, and tumor size as potential predictors of invasive treatment. A total of 91 patients with AMLs were identified. The mean patient age was 57 years. Seventy-three (83.9%) patients presented incidentally, and 14 (16%) patients were symptomatic at presentation. Forty-five patients were treated with AS, 4 underwent embolization, and 38 patients had extirpative surgery. After a median follow-up of 54.8 months (range 0.2-211.7 mos), there was a mean growth rate of 0.088 cm/year in the group who were treated with AS. AS failed in three patients. Two patients had retroperitoneal bleeding during the observation period, and one patient manifested an expeditious growth rate of 0.7 cm/year and underwent a radical nephrectomy. AML is a renal tumor that usually exhibits a benign course. Surgical removal and embolization are the standard invasive treatment modalities. AS for AMLs is associated with a slow and consistent growth rate (0.088 cm/year), typically has minimal morbidity, and is a reasonable option in selected patients. Symptomatic presentation and size (> 3 cm) are not predictive for necessitating an invasive procedure.

Imaging

OBJECTIVE. The purpose of this study was to determine whether counts of pixels with subzero attenuation on CT scans can aid in the diagnosis of renal angiomyolipoma with minimal fat.MATERIALS AND METHODS. Of 33 angiomyolipomas identified among 719 renal masses resected from 702 patients over 4 years, 15 masses in 15 patients were prospectively diagnosed on the basis of the presence of fat at MDCT. The 18 patients with minimal-fat angiomyolipoma and a matched (age, sex, tumor size) cohort of patients with renal cell carcinoma were included in this study. Three radiologists independently counted the number of pixels with attenuation less than –10, –20, and –30 HU. Receiver operating characteristic analysis of the number of pixels at each cutoff was used to calculate sensitivity, specificity, and positive predictive value with the following criteria: 1, more than 10 pixels less than –20 HU; 2, more than 20 pixels less than –20 HU; 3, more than 5 pixels less than –30 HU.RESULTS. Using criterion 1, reader A id...

Angiomyolipoma with Minimal Fat on MDCT: Can Counts of Negative-Attenuation Pixels Aid Diagnosis?

The purpose of this study was to determine whether counts of pixels with subzero attenuation on CT scans can aid in the diagnosis of renal angiomyolipoma with minimal fat. Of 33 angiomyolipomas identified among 719 renal masses resected from 702 patients over 4 years, 15 masses in 15 patients were prospectively diagnosed on the basis of the presence of fat at MDCT. The 18 patients with minimal-fat angiomyolipoma and a matched (age, sex, tumor size) cohort of patients with renal cell carcinoma were included in this study. Three radiologists independently counted the number of pixels with attenuation less than -10, -20, and -30 HU. Receiver operating characteristic analysis of the number of pixels at each cutoff was used to calculate sensitivity, specificity, and positive predictive value with the following criteria: 1, more than 10 pixels less than -20 HU; 2, more than 20 pixels less than -20 HU; 3, more than 5 pixels less than -30 HU. Using criterion 1, reader A identified six angiomyolipomas; reader B, five; and reader C, two. The combined sensitivity was 24%; specificity, 98%; and positive predictive value, 69%. Using criterion 2, reader A identified three angiomyolipomas; reader B, four; and reader C, two. The combined sensitivity was 17%; specificity, 100%; and positive predictive value, 100%. Using criterion 3, reader A identified four angiomyolipomas; reader B, four; and reader C, two. The combined sensitivity was 18%; specificity, 100%; and positive predictive value, 100%. CT findings of more than 20 pixels with attenuation less than -20 HU and more than 5 pixels with attenuation less than -30 HU have a positive predictive value of 100% in detection of angiomyolipoma, but most angiomyolipomas with minimal fat cannot be reliably identified on the basis of an absolute pixel count.

Rupture d'un angiomyolipome rénal lors d'une grossesse

A 40 year-old 2nd gesta pregnant woman (34.5 weeks of amenorhea) was admitted to hospital for abdominal pain and arterial hypotension which were rapidly related to a retroperitoneal haematoma due to left kidney bleeding. Emergency cesarean delivery under general anaesthesia was undertaken because of foetal distress. Exploration of the retroperitonal space after foetal extraction confirmed the presence of a large haematoma and abnormal left renal morphology. The retroperitoneal space was drained without any further intervention. Subsequently, abdominal and thoracic computerised tomographic examination showed bilateral dysplasia of the kidneys and pulmonary cysts consistent with the diagnosis of renal angiomyolipoma and pulmonary lymphangioleiomyomatosis. The case report is of interest because of the circumstances of discovery of the disease and because nephrectomy was not necessary to control the bleeding of the left kidney. Six months after the incident the patient and the child are in good condition.

The Use of Opposed-Phase Chemical Shift MRI in the Diagnosis of Renal Angiomyolipomas

The objective of our study was to determine the reliability of the location of the india ink artifact and signal loss on opposed-phase chemical shift MRI to differentiate angiomyolipomas from solid renal masses and from hemorrhagic-proteinaceous renal cysts. Twenty-three angiomyolipomas, 24 hemorrhagic-proteinaceous cysts, and 23 solid renal masses (nonangiomyolipomas) were retrospectively evaluated at 1.5 T with chemical shift MRI using TEs of 2.1-2.7 msec (opposed phase) and 4.8-5.3 msec (in phase). Two independent observers reviewed the MR images for signal loss on opposed-phase images and for the presence or absence of india ink artifact. An angiomyolipoma was diagnosed if the india ink artifact was identified at the interface of the mass and the kidney or was present within the renal mass. Twenty-three (100%) of the 23 angiomyolipomas showed india ink artifact within the mass or at its interface with the kidney, and 18 (78.3%) of the 23 angiomyolipomas showed signal loss on opposed-phase MR images. In 24 (100%) of the 24 hemorrhagic-proteinaceous cysts, india ink artifact was not present within the mass or at its interface with the kidney. No signal loss was seen in hemorrhagic-proteinaceous cysts on opposed-phase MR images. In one (4%) of the 23 solid (nonangiomyolipoma) renal masses, the india ink artifact was identified at the interface of the mass with the kidney, and in two (9%) of the 23 masses, loss of signal was identified on the opposed-phase MR images. The presence of india artifact at a renal mass-kidney interface or within a renal mass is indicative of angiomyolipoma.

Fine‐needle aspiration of renal angiomyolipoma: Cytological findings and diagnostic pitfalls in a series of five cases

Diagnosis of renal angiomyolipoma (AML) by fine-needle aspiration (FNA) may be difficult because cytological and radiological findings sometimes overlap with renal cell carcinoma (RCC) and liposarcoma. Five FNAs of AMLs were studied. Epithelioid and spindle stromal cells were arranged in loosely cohesive clusters and singly. The chromatin was evenly distributed and bland. Occasionally nuclear atypia was identified. Nuclei were oval to elongated, nucleoli were inconspicuous or absent, naked nuclei were present in three specimens, and intranuclear inclusions were present in two specimens. The cytoplasm was delicate and sometimes finely vacuolated. Adipose tissue was observed in two specimens. Thick-walled vessels, mitoses, and necrosis were absent. Corresponding surgical material showed typical features of AML. In FNA, bland chromatin and inconspicuous nucleoli distinguish renal AML from RCC and liposarcoma. Adipose tissue is not universally present. Cellular atypia in conjunction with overlapping radiological findings with RCC and liposarcoma are potential diagnostic pitfalls. Immunocytochemical (ICC) stains may elucidate the correct diagnosis.

Renal masses detected by general health checkup

A total of 60,604 persons underwent a general health checkup at Toma Hospital, Saitama, Japan, between January 1993 and June 1997, and transabdominal ultrasonography (US) was performed on all persons. We investigated the usefulness of transabdominal US in detecting renal tumors during general health checkups. A definite diagnosis was made in cases where the re-examination by US revealed calculus with acoustic shadow or a simple cyst. Computed tomography (CT) was conducted in patients suspected of having a renal tumor, and a diagnosis of renal angiomyolipoma (AML) was made if plain CT gave evidence of a fatty component. Patients diagnosed as having a renal cell carcinoma (RCC) with non-uniform enhancement underwent nephrectomy. If a definite diagnosis could not be made even by contrast CT, the monitoring by US and contrast CT once a year was continued. Of 97 (0.16%) patients whose transabdominal US findings indicated a diagnosis of suspected renal tumor, 58 underwent the re-examination by US; of these, CT was conducted in 47. Detailed US revealed a hyperechoic pattern in 44 patients, a mixed pattern in nine and an isohypoechoic pattern with internal echo in five. By plain CT, 24 patients were diagnosed as having AML, and two as having renal calcification. Contrast CT enabled a diagnosis of renal cyst to be made in two patients and renal tumor in 14. All 14 patients with RCC except one underwent nephrectomy, which provided pathologic evidence supporting the diagnosis. Five patients had a tumor unidentifiable by CT, with continuing periodic follow-up by US and CT. Eleven patients underwent no CT. Of the 60,604 persons who underwent a general health checkup, we found 14 cases of RCC and 24 cases of AML. As a small RCC has a favorable prognosis, patients greatly benefit from early detection; therefore, we should recognize the importance of identifying renal masses by US screening during general health checkups.

A CASE OF SUDDEN ONSET OF RENAL ANGIOMYOLIPOMA TREATED BY TRANSARTERIAL EMBOLIZATION WITH ABSOLUTE ETHANOL

A 34-year-old woman was admitted to the hospital because of sudden onset of left flank pain. Ultrasonography and CT findings revealed a left giant renal tumor. The tumor was 13×11×20cm in size and composed of fatty tissue in the most part. A lesion which seemed to be hematoma surrounded the left kidney. She was diagnosed with retroperitoneal bleeding due to rupture of the renal tumor, and underwent abdominal angiography. It was revealed that the tumor was fed by three dilated and tortuous vessels of branches from the renal artery. A diagnosis of renal angiomyolipoma was made. These tumor vessels were embolized with 5ml of absolute ethanol superselectively. Post embolized course was uneventful and the tumor revealed a decrease in size on CT 9 days after TAE. She has been asymptomatic for 5 years. Transarterial embolization with absolute ethanol is first recommended for renal angiomyolipoma.

Bilateral Renal Angiomyolipoma: Involvement of the Contralateral Kidney after 25 Years – An Unusual Case

The diagnosis of renal angiomyolipoma often poses problems, both clinically and pathohistologically. With the increasing refinement of imaging techniques it is becoming potentially possible to recognize these benign neoplasms by means of ultrasound, computed tomography and magnetic resonance imaging. Electron microscopy and histochemical methods are often necessary for the correct pathological diagnosis. The problems involved are presented on the basis of the case history of a patient who suffered from renal angiomyolipoma in both kidneys with an interval of 25 years. The first tumor was diagnosed histologically as a liposarcoma 25 years ago.