[Usefulness of Electron Density Calculated from Dual Energy CT in Differential Diagnosis between Hepatocellular Carcinoma and Hepatic Hemangioma]

PURPOSE

The aim of this study were to compare electron density (ED), obtained by dual energy computed tomography (DECT), between hepatocellular carcinoma (HCC) and hemangioma, and to assess the differential diagnostic performance of ED between HCC and hemangioma.

METHODS

A total of 46 patients (27 men and 19 women; mean age, 65.7±14.0 years) diagnosed with HCC or hemangioma who underwent upper abdominal DECT between October 2021 and December 2022 were included. ED of each lesion was measured. Relative ED (rED), which is normalized by the ED of background liver parenchyma, was calculated. ED and rED of HCC and hemangioma were statistically analyzed.

RESULTS

The HCC group showed significantly higher ED (48.1±5.2) and rED (80.0±7.3) than the hemangioma group (43.7±4.1, 69.7±7.2, respectively) (p<0.01). The area under the curve of rED was greater than that of ED, but no significant difference was found (p=0.153).

CONCLUSION

ED may help in the differential diagnosis between HCC and hemangioma.

Clinical Practice Guidelines for tuberous sclerosis complex-associated renal angiomyolipoma by the Japanese Urological Association: Summary of the update

New clinical issues have been raised through an interval of 7 years from the previous version (2016). In this study, we update the "Clinical Practice Guidelines for tuberous sclerosis complex-associated renal angiomyolipoma" as a 2023 version under guidance by the Japanese Urological Association. The present guidelines were cooperatively prepared by the Japanese Urological Association and Japanese Society of Tuberous Sclerosis Complex; committee members belonging to one of the two societies or specializing in the treatment of this disease were selected to prepare the guidelines in accordance with the "Guidance for preparing treatment guidelines" published by Minds (2020 version). The "Introduction" consisted of four sections, "Background Questions (BQ)" consisted of four sections, "Clinical Questions (CQ)" consisted of three sections, and "Future Questions (FQ)" consisted of three sections (total: 14 sections). Concerning CQ, an agreement was confirmed through voting by the committee members based on the direction and strength of recommendation, accuracy of evidence, and recommendation comments. The present guidelines were updated based on the current evidence. We hope that the guidelines will provide guiding principles for the treatment of tuberous sclerosis complex-associated renal angiomyolipoma to many urologists, becoming a foundation for subsequent updating.

Renal angiomyolipoma with tuberous sclerosis complex: How it differs from sporadic angiomyolipoma in both management and care

Renal angiomyolipoma (AML) is the most common benign tumor of the kidney. It consists of blood vessels, smooth muscle and fat components in varying proportions. AML is divided into the sporadic type and tuberous sclerosis complex (TSC)-associated type. TSC-associated AML develops at a younger age and tends to exhibit a much faster growth rate over time than sporadic AML. AMLs are classified as classic AML, fat-poor AML and epithelioid AML. Epithelioid AML, though rare, shows aggressive behavior leading to distant metastasis and mortality. TSC-associated AML is more likely to have an epithelioid component than sporadic AML. Active surveillance is the suggested management for small AML. Clinical intervention is mainly indicated when there is a substantial risk of rupture. Minimally invasive therapies, including partial nephrectomy, transcatheter arterial embolization, and mammalian target of rapamycin (mTOR) inhibitor treatment are employed for patients who require treatment. An updated algorithm for the management of AML is herein described. According to this algorithm, treatment intervention is recommended for TSC-associated AML >3 cm, even in asymptomatic cases. In cases with asymptomatic sporadic AML >4 cm in size or with an intra-tumoral aneurysm of >5 mm, treatment, including transcatheter arterial embolization or partial nephrectomy, is advised. The major complication of AML is intra-tumoral or retroperitoneal hemorrhage due to rupture that may be serious and life threatening. Thus, correct diagnosis, proper observation, and appropriate treatment are very important in the management of renal AML.

Differentiation of Sporadic Versus Tuberous Sclerosis Complex-Associated Angiomyolipoma

OBJECTIVE

We review the imaging of renal angiomyolipomas, including differentiation of tuberous sclerosis complex (TSC)-associated and sporadic renal angiomyolipomas and other solid renal tumors. We also focus on radiologic interventions and molecular targeting of the TSC genetic pathway.

CONCLUSION

Imaging plays a central role in the diagnosis and management of renal angiomyolipomas. It provides essential information to make the best therapeutic decisions about the interventional and pharmacologic options to help prevent bleeding and preserve functional parenchyma.

Contemporary diagnosis and management of renal angiomyolipoma

PURPOSE

We present a comprehensive resource that summarizes contemporary advances relevant to the clinical management of renal angiomyolipoma.

MATERIALS AND METHODS

A MEDLINE search was done using the key words angiomyolipoma, hemangioma or lipoma and kidney neoplasm, and therapeutic embolization. References from these articles were reviewed to identify additional relevant source material. We identified 13 series published since 1986 comprising 336 patients as well as 24 reports of therapeutic embolization for angiomyolipoma, comprising 76 patients. To our knowledge we report the largest compilation series to date.

RESULTS

Angiomyolipoma is generally benign, although an uncommon subtype (epithelioid angiomyolipoma) may behave more aggressively. Tuberous sclerosis associated angiomyolipoma tends to be larger, multiple and more likely to cause spontaneous hemorrhage than the sporadic entity. Tumors that hemorrhage tend to be larger. Computerized tomography or magnetic resonance is usually sufficient for diagnosis. Biopsy is rarely useful. Primary indications for intervention include symptoms such as pain or bleeding or suspicion of malignancy. Prophylactic intervention is justifiable for large tumors, in females of childbearing age or in patients in whom followup or access to emergency care may be inadequate. Recent advances that have affected management include improved understanding of tuberous sclerosis complex and angiomyolipoma genetics, the identification of molecular markers that facilitate histopathological diagnosis, and the refinement of embolization and partial nephrectomy techniques.

CONCLUSIONS

Although some cases of angiomyolipoma may require complete nephrectomy, most can be managed by conservative nephron sparing approaches. Ongoing research into the molecular biology and clinical behavior of angiomyolipoma may improve our ability to manage these lesions.

Giant bleeding renal angiomyolipoma: diagnosis and management

A case of a giant bleeding renal angiomyolipoma is presented. The patient was a 40-year-old Egyptian male with no clinical or radiological evidence of tuberous sclerosis. The radiological features and management, including the role of angiography are briefly discussed and the medical reviews on this subject are briefly considered.

Management of renal angiomyolipoma: a report of 53 cases

OBJECTIVE

To evaluate the clinical, therapeutic and prognostic aspects of renal angiomyolipoma (AML) in patients either monitored by clinical and radiological follow-up or treated by surgical therapy.

PATIENTS AND METHODS

Fifty-three patients with renal AML were divided in two groups; 33 patients in group 1 were monitored by annual clinical and ultrasonographic follow-up and 20 in group 2 were treated with surgical therapy. Two patients had tuberous sclerosis (TS) with synchronous bilateral and multiple lesions. Apart from the patients with TS, there were 38 lesions in group 1 and 25 in group 2. The mean (range) follow-up of group 1 was 60.2 (12-164) months.

RESULTS

In group 1, the diagnosis was most often incidental, after ultrasonography performed for symptoms unrelated to AML. In group 2, the suspicion of a malignant renal lesion, and spontaneous tumour rupture with bleeding and perirenal haematoma, were the main indications for surgical treatment. The mean lesion diameter was significantly greater in group 2 (5.4 cm) and in symptomatic patients (8.1 cm). In group 1, 92% of renal AMLs showed no radiographic changes, serious complications or new renal or extrarenal lesions during the follow-up. Only three lesions grew, after 22, 85 and 164 months, respectively. Of the 20 patients in group 2, 14 underwent conservative surgery.

CONCLUSION

Small (<4 cm) isolated AMLs, detected incidentally, showed a low risk of developing during long-term follow-up. Such patients may be followed conservatively by ultrasonography every 2 years. Spontaneous perinephric haemorrhage is related to the size of the lesion. When surgery is indicated (by symptoms or diagnostic doubt), a conservative procedure can be performed in most of cases.

Radiological parameters of bleeding renal angiomyolipoma

Angiomyolipomas are rare tumours of the kidney which have a tendency to bleed. We studied the clinical and radiological features of 11 patients from our institution to identify features which may be predictive of a massive haemorrhage. Tumours more than 6 cm in diameter were found to bleed and the demonstration of pseudoaneurysms on contrast CT scanning was associated with massive haemorrhage. We conclude that large angiomyolipomas should be treated to avoid haemorrhage and the detection of pseudoaneurysms should prompt urgent treatment.

Small echogenic renal masses: how often is computed tomography used to confirm the sonographic suspicion of angiomyolipoma?

OBJECTIVES

Although renal angiomyolipoma (AML) has a typical ultrasound appearance, many authorities suggest that a computed tomography (CT) scan be obtained to confirm the diagnosis because small echogenic renal cell carcinomas can simulate AML. Our study evaluates the actual follow-up in such patients and factors that may affect whether CT confirmation is recommended or obtained.

METHODS

From 1986 through 1992, 36 patients had an ultrasound diagnosis of probable renal AML (well-circumscribed, homogenously echogenic mass). In each case the patient's age, symptoms, ultrasound results and recommendations, and imaging follow-up were recorded.

RESULTS

CT confirmation of the sonographic diagnosis was recommended in only 11 of 36 (31%) patients. Only 7 of these 11 patients actually underwent CT, 5 of whom had the diagnosis confirmed by CT detection of intratumoral fat. Ten of 23 patients (43%) over 50 years of age had CT recommended, whereas only 1 of 13 (8%) patients under age 50 years did (P < 0.05). CT confirmation was recommended for 5 of 13 (38%) lesions greater than 10 mm and for 6 of 23 (26%) smaller masses. None of the 9 patients under age 50 years with small masses (less than 10 mm) had CT recommended.

CONCLUSIONS

Although many authorities recommend CT to confirm the sonographic diagnosis of renal AML, this algorithm is rarely followed in everyday clinical practice, especially in patients under age 50 years with masses less than 10 mm.

Spontaneous haemorrhage from renal angiomyolipomata

Spontaneous rupture is an uncommon but catastrophic complication of renal angiomyolipoma. Intrarenal haematomas and aneurysms are predictors of tumour rupture. Early detection by computed tomography followed by embolization may be life saving.

Adult onset of renal angiomyolipoma in a patient with tuberous sclerosis

The growth of renal angiomyolipomas in adult tuberous sclerosis patients has not been previously reported. We report one such case of the growth of an angiomyolipoma in a previously documented angiographically normal appearing kidney after the contralateral kidney was removed for angiomyolipoma 15 years earlier.