Diagnosis and treatment of renal angiomyolipoma (based on 15 cases). Arguments in favor of conservative surgery (based on 8 cases)

[Angiomyolipoma and Lenk syndrome: case report]

Angiomyolipoma (AML) is a benign clonal neoplasm that consists of varying amounts of mature adipose tissue, smooth muscle, and thick-walled vessels. Approximately 20% of AMLs are found in patients with tuberous sclerosis syndrome (TS), an autosomal-dominant disorder characterized by mental retardation, epilepsy, and adenoma sebaceous, a distinctive skin lesion. Massive retroperitoneal hemorrhage from AML, also known as Wunderlich's syndrome, has been found in up to 10% of patients and represents the most significant and feared complication. The presence of even a small amount of fat within a renal lesion on CT scan (confirmed by Hounsfield unit's < or = 10) is considered diagnostic of AML. Intervention should be considered for larger tumors, particularly if the patient is symptomatic, taking into account patient age, comorbidities, and other related factors. A nephron-sparing approach, via either partial nephrectomy or selective embolization, is clearly preferred. We present the case of a fifty-nine-year old patient with an angiomyolipoma and massive retroperitoneal hemorrhage with Lenk syndrome.

A case of huge colon carcinoma and right renal angiomyolipoma accompanied by proximal deep venous thrombosis, pulmonary embolism and tumor thrombus in the renal vein

A preoperative inferior vena cava (IVC) filter is reported to be effective in surgical cases with proximal deep venous thrombosis (DVT) or in which pulmonary embolism (PE) has already developed, and considered to be at high risk of developing secondary fatal PE during or after surgery. However, guidelines for using an IVC filter have yet to be established. The patient in the present report had two huge tumors, ascending colon cancer and renal angiomyolipoma, which occupied the entire right half of the abdomen, coexisting PE, DVT and tumor thrombus in the right renal vein. Secondary PE is fatal in the perioperative period, therefore, the vena cava filters were preoperatively inserted into the supra- and the infrarenal IVC. We successfully removed the tumors without complications. The patient is alive without tumor recurrence and PE or recurrent DVT 1 year and 6 months after surgery. The coexistence of two huge abdominal tumors as potential causes of PE and DVT is extremely rare, and we could have safely undergone the operation, using two vena cava filters in the supra- and infrarenal IVC.

Fine-needle aspiration of renal angiomyolipoma: a report of four cases

OBJECTIVE

Renal angiomyolipoma is an uncommon benign tumour composed of smooth muscle cells, blood vessels and adipose tissue. The cytological findings of this tumour are described.

METHODS

A retrospective analysis of four cases of angiomyolipoma diagnosed on fine-needle aspiration cytology (FNAC) during the period 1998-2004 was carried out. All the aspirations were carried out under ultrasonographic image guidance.

RESULTS

Smears from three cases showed oval- to spindle-shaped tumour cells, cohesive stromal fragments embedded in adipose tissue and branching blood vessels in a haemorrhagic background. No mitotic figures were seen. Smears from one case showed adipose tissue and blood. In this case, sections from the cell block showed mature adipose tissue and small blood vessels.

CONCLUSION

The diagnosis of angiomyolipoma can be made by FNAC under image guidance and a cell block may be quite helpful in making a correct diagnosis. It is important to establish a correct preoperative diagnosis as treatment of these tumours is conservative and this obviates the need for total nephrectomy.

Hemorragia retroperitoneal espontánea: nuestra experiencia en los últimos 10 años

INTRODUCTION AND OBJECTIVES

Etiology, clinical features, diagnostic methods and treatment of spontaneous retroperitoneal hemorrhage were analyzed.

METHODS

We report 27 cases with diagnosis of spontaneous retroperitoneal hemorrhage treated in our hospital between January 1996 and December 2005. The imaging techniques were abdominal ultrasonography, abdominal CT scan and MRI.

RESULTS

The most common cause of retroperitoneal hemorrhage was renal angiomyolipoma rupture in 7 patients. Continuous flank or abdominal pain were the primary symptoms. Abdominal ultrasonography showed hematoma in 81.8% patients, but the actual etiologic diagnosis was ascertained in only 40.9% of them. Retroperitoneal hemorrhage was demonstrated by means of abdominal CT scan in all cases and bleeding origin was established in 92.6% of cases. Ten patients underwent urgent surgery while conservative treatment was attempted in the remaining 17.

CONCLUSIONS

In our experience, in cases of spontaneous retroperitoneal hemorrhage, CT scan is the best imaging method to establish the diagnosis and the management of such entity although it will need to be individualized for every case because it depends on the hemodinamic situation and etiologic diagnosis.

Bilateral giant renal angiomyolipoma associated with hepatic lipoma in a patient with tuberous sclerosis

OBJECTIVE

To report a case of bilateral giant renal angiomyolipoma associated with tuberous sclerosis, with successful treatment, and to review the literature concerning angiomyolipoma treatment.

CASE REPORT

Patient with tuberous sclerosis and angiomyolipoma diagnosed by ultrasonography during her pregnancy. At that time, the angiomyolipoma on the right side was 9 cm in diameter. Conservative management was selected during her pregnancy. The patient returned 7 years later, with a 24.7 x 19.2 x 10.7 cm tumor on the right side and another of 13 x 11.5 x 6.5 cm on the left side, in addition to multiple small angiomyolipomas. A nephron-sparing surgery with tumoral enucleation was performed on the right side, and after 3 months, the tumor on the left side was removed. Renal function in the post-operative period was preserved, and contrast medium progression was uniform and adequate in both kidneys.

CONCLUSION

We conclude that an angiomyolipoma larger than 4 cm should be removed surgically, since they have a greater growth rate and pose a risk of hemorrhage. Resection of smaller tumors is safe and has decreased morbidity. Tumoral enucleation is an effective treatment method that preserves kidney function.

Pulmonary lymphangioleiomyomatosis. A study of 69 patients. Groupe d'Etudes et de Recherche sur les Maladies "Orphelines" Pulmonaires (GERM"O"P)

Pulmonary lymphangioleiomyomatosis (LAM) is a rare disorder of unknown cause characterized by peribronchial, perivascular, and perilymphatic proliferation of abnormal smooth muscle cells leading to cystic lesions. The hypothesis of hormonal dependence and the effectiveness of hormonal therapy have not yet been demonstrated conclusively, and the prevalence of extrathoracic manifestations and the survival of patients with LAM are somewhat contradictory. A multicentric retrospective study was conducted in an attempt to describe better the initial features, the diagnostic procedures, the associated lesions, and, above all, the management and course of LAM in a large homogeneous series of 69 stringently selected patients, with a majority of cases diagnosed since 1990. The aim of the study, based on a review of the literature, also was to provide a comprehensive view of this uncommon disease. The clinical features were in keeping with previous studies, but we found that exertional dyspnea and pneumothorax were the most common features, and chylous involvement was less frequent. LAM was diagnosed after menopause in about 10% of cases. The onset of LAM occurred during pregnancy in 20% of cases, and a clear exacerbation of LAM was observed in 14% of cases during pregnancy. Pulmonary LAM was diagnosed on lung histopathology in 83% of cases, but renal angiomyolipoma, observed in 32% of our patients, may be a useful diagnostic criterion when associated with typical multiple cysts on chest CT scan or with chylous effusion. Chest CT scan was more informative than chest X-ray (normal in 9% of cases), and may be indicated in spontaneous pneumothorax or renal angiomyolipoma in women of childbearing age. About 40% of the patients had a normal initial spirometry, while an obstructive ventilatory defect (44%), a restrictive ventilatory defect (23%), was observed in other patients. Initial diffusing capacity for carbon monoxide was frequently decreased (82%). Hormonal therapy was administered in 57 patients, but a clear > or = 15% improvement of FEV1 was observed in only 4 evaluable patients, treated with tamoxifen and progestogens (n = 2), progestogen (n = 1), and oophorectomy (n = 1). Probably 1 of the most urgent needs for clinical research in LAM is to test the currently available hormonal treatments in the context of international multicenter prospective controlled studies. Pleurodesis was performed in 40 patients. Lung transplantation was performed in 13 patients, 7.8 +/- 5.2 years after onset of LAM, in whom the mean FEV1 was 0.57 +/- 0.15 L. After a follow-up of 2.3 +/- 2.2 years, 9 patients were alive. Mean follow-up from onset of disease to either death or closing date was 8.2 +/- 6.3 years. Overall survival was better than usually reported in LAM, and Kaplan-Meier plot showed survival probabilities of 91% after 5 years, 79% after 10 years, and 71% after 15 years of disease duration.

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.

Renal angiomyolipoma in children: diagnositc difficulty in 3 patients

PURPOSE

Because angiomyolipoma is less common in children than in adults, its diagnosis can be difficult. We present 3 cases of pediatric angiomyolipoma in which diagnostic problems resulted due to the presenting characteristics.

MATERIALS AND METHODS

We report on 3 children with unilateral renal angiomyolipoma. Computerized tomography (CT) and ultrasonography revealed 3 large renal masses, 20, 7 and 8 cm. in diameter, respectively. A correct diagnosis was not made preoperatively in any case by CT, ultrasound or fine needle biopsy. Wilms tumor was suspected in the first patient who received preoperative chemotherapy. Imaging was inconclusive in the other 2 cases.

RESULTS

All patients underwent surgical exploration and subsequent nephrectomy due to the large size of the tumor. At followup 33, 23 and 13 months postoperatively all children were well without signs of recurrence.

CONCLUSIONS

It has been reported that the demonstration of fat on renal ultrasound and CT can diagnose angiomyolipoma in 95% of the cases. Most radiologists rely solely on CT demonstration of lipid density in the renal mass to diagnose angiomyolipoma but the identification at imaging of lipid tissue may be difficult in small tumors. In our cases the fat content of the tumors was less than 10% despite the large size. This low fat content results in misdiagnosis, since fatty tissue is also present in other renal tumors, such as lipoma, liposarcoma, teratoma and Wilms tumors. We recommend conservative surgery when tumor size permits in pediatric patients with angiomyolipoma to avoid chemotherapy.

Fine-needle aspiration cytology of renal angiomyolipoma: report of a case with immunocytochemical and electron microscopic findings

A case is presented in which the diagnosis of renal angiomyolipoma was made by computed tomography (CT)-guided, fine-needle aspiration cytology and the examination of a cell block. The tumor was characterized by epithelioid smooth muscle cells, blood vessels and fat in the cytologic material. The cytodiagnosis was further substantiated by positive staining of the epithelioid muscle cells for markers of muscle-specific actin, HMB45, and trace positivity for vimentin but not with S100 protein, desmin, or cytokeratin. Further studies for the recently described crystalloids were also performed by using the periodic-acid Schiff stain with and without diastase treatment and electron microscopy on the cytologic material. However, no such crystalloids were found. A preoperative cytologic diagnosis of renal angiomyolipoma was considered to be of value due to the difference in management between angiomyolipoma and a renal carcinoma, both of which can present as a renal mass on imaging.

[Renal angiomyolipoma and pulmonary lymphangiomyomatosis: a non-fortuitous association]

Angiomyolipoma is a rare tumor, frequently associated with tuberous sclerosis, but not observed in its isolated form. Usually, patients with tuberous sclerosis presented with pathognomonic cutaneous and central nervous system lesions. But the thesis of "formes frustes" without typical stigmata was suggested. A case of bilateral and multifocal angiomyolipoma in a young woman without evidence of phacomatosis is reported. The association with a pulmonary lymphangiomatosis make us suspected "a forme fruste" of tuberous sclerosis.

Cytologic study of renal angiomyolipoma by fine-needle aspiration biopsy: report of four cases

Four cases of renal angiomyolipoma (AML) diagnosed by fine-needle aspiration biopsy (FNAB) are reported. One case was associated with the clinical complex of tuberous sclerosis. The tumors were solitary in two cases and multiple and bilateral in the fourth. The cytologic features of the four cases were similar to those described in the literature: smooth muscle cells intermingled with mature fat cells and blood vessels, together with a lipoidic background. These tumors are currently considered benign although they may present characteristics accepted as criteria of malignancy in other tumors: pleomorphism and atypical smooth muscle cells, vascular invasion, capsular rupture, and lymphatic involvement. We conclude that it is important and possible to establish preoperative cytologic diagnosis, since treatment of these tumors is conservative and obviates aggressive nephrectomy.

The natural history of renal angiomyolipoma

Of 35 patients with 48 angiomyolipomas 24 patients were followed clinically to determine the natural history of angiomyolipoma. Average patient age at presentation was 50 years (range 17 to 74) and of the patients 94% were women, 17% had tuberous sclerosis and 25% overall had bilateral disease. The patients could be divided into 2 distinct groups based on tumor size of 4 cm. or less and greater than 4 cm. Those with tumors less than 4 cm. were less likely to be symptomatic (24%) and patients with angiomyolipomas greater than 4 cm. were more often symptomatic (52%). No surgery was required for tumors less than 4 cm. but for 30% of the tumors greater than 4 cm. surgical intervention was necessary. Unlike any previously reported large series this study included radiological and historical followup available for 24 patients with angiomyolipoma with a mean followup time of 4 years (range 0.5 to 14). Moreover, to our knowledge we report for the first time documented growth during the study period of 27% of angiomyolipomas less than 4 cm. (4 of 15 tumors) and 46% of angiomyolipomas greater than 4 cm. (6 of 13 tumors). All patients with tumors less than 4 cm. were asymptomatic and only 1 required surgery. In contrast, tumors greater than 4 cm. were more frequently symptomatic (46%) and required surgery (54%). Patients with tuberous sclerosis and angiomyolipomas were distinctly different from patients with angiomyolipoma only, since they tended to present at a younger age, had a higher incidence of bilateral renal involvement, were more symptomatic, had larger tumors that were more likely to grow, and frequently required surgery. Based on this study, a modified approach to the current management of angiomyolipoma is recommended.

Diagnostic and therapeutic problems in multicentric renal angiomyolipoma

Multicentric renal angiomyolipoma is a rare form of benign tumor. However, its effective incidence as evaluated in autopsy studies may be as high as 8%. There are 2 main types of renal angiomyolipoma, that is isolated forms and those associated with other diseases, such as phakomatosis, polycystic kidneys and fibromuscular dysplasia. The tumor may also display malignant behavior with local invasiveness and regional lymph node involvement. However, the clinical course is benign and multicentricity is important for prognosis. Histopathological diagnosis often is difficult. Immunohistochemical analysis of surgical specimens using a panel of monoclonal antibodies, including HMB-45 and actin, enabled us to make a definitive diagnosis in 3 cases of multicentric renal angiomyolipoma.

Multicentric angiomyolipoma: renal and lymph node involvement

A retrospective review of 6 patients with renal angiomyolipoma treated surgically revealed regional lymph node involvement in 2--an incidence of 33 per cent. The clinical behavior in these patients suggests that nodal involvement is an expression of multicentricity rather than metastatic disease.

Spontaneous intraperitoneal rupture of a kidney in a patient with tuberous sclerosis

A case is reported of spontaneous intraperitoneal rupture of a kidney in a patient with tuberous sclerosis who presented with left renal colic and left lower quadrant abdominal pain.

Diagnosis and treatment of renal angiomyolipoma

A series of nine patients surgically treated for histologically verified renal angiomyolipoma is presented. Only one patient had extrarenal stigmata of tuberous sclerosis. No evidence of malignancy was found. In three cases a preoperative diagnosis was achieved with computed tomography (CT), use of which is recommended in evaluation of renal tumours. Six angiomyolipomas were solitary and three bilateral. Abdominal or flank pain was present in eight cases and perirenal haemorrhage in four. Solitary tumours were treated with nephrectomy. For bilateral tumour, nephrectomy and conservative renal surgery were used in two cases and bilateral nephrectomy and kidney transplantation were performed in the third case. When adipose tissue containing renal tumour is demonstrated at CT, conservative surgery should be considered.

Diagnosis and management of renal angiomyolipoma

Renal angiomyolipoma (hamartoma) is an uncommon benign tumor of the kidney. Although about 400 cases of renal angiomyolipoma have been reported, it still causes difficulties in diagnosis and treatment. Until a few years ago it was almost impossible to arrive at a correct diagnosis preoperatively, and most of the cases underwent nephrectomy with the wrong diagnosis of renal carcinoma. More recently, abdominal computerized tomography and renal sonography have made it possible to reach the correct preoperative diagnosis in many cases, and thus to avoid unnecessary nephrectomies. We report on our experience with 13 cases of renal angiomyolipoma, and our conservative approach in a number of cases, which has enabled us to preserve renal tissue and function.

Renal tumors associated with tuberous sclerosis: the case for aggressive surgical management

Tuberous sclerosis is associated commonly with renal angiomyolipoma. However, the radiographic differentiation of angiomyolipoma and renal carcinoma can be difficult, and the natural history of angiomyolipoma may be associated with serious complications. We present a case of bilateral renal cell carcinoma associated with tuberous sclerosis. Aggressive but conserving renal surgery should be considered in patients with tuberous sclerosis and enlarging renal masses.

[Angiomyolipoma of the kidneys in Bourneville-Pringle disease]

Three cases with renal angiomyolipoma in Bourneville's disease are reported. In two patients advanced renal insufficiency developed, one being treated by chronic intermittent hemodialysis. In the third patient rupture of angiomyolipoma with severe retroperitoneal bleeding occurred. In one patient, tumorous enlargement initially was diagnosed only in the right kidney and preceded angiomyolipoma of the left kidney for several years. In this patient nephrectomy was performed because malignancy was assumed before diagnosis of Bourneville's disease was established. Occasionally, histology may suggest sarcomatous changes. However, the absence of distant metastasis and the overall long survival of patients with renal angiomyolipoma in Bourneville's disease underline the benign character of the tumor. Treatment should be conservative because surgical intervention with loss of kidney parenchyma may enhance progression to end-stage renal failure.

Spontaneous intrapartum rupture of renal hamartoma

Spontaneous rupture of a renal hamartoma during pregnancy is a rare condition. Increased blood volume, increased renal blood flow, and vascular changes secondary to a change in the hormonal milieu may predispose to rupture in pregnancy. The diagnosis is made difficult by a desire to proceed cautiously and avoid the inherent risks of interventional radiography, aggressive surgical therapy, or conservative management as well. However, a conservative approach may be successful in selected cases.