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.     

Solitary fibrous tumor of the adrenal gland with renal cell carcinoma and angiomyolipoma at the same time; a case report

Solitary fibrous tumor (SFT) is a neoplasm of pleura and its occurrence in the retroperitoneal space is rare. We report a case of SFT of the adrenal gland associated with ipsilateral renal cell carcinoma (RCC) and angiomyolipoma (AML). A 48-year-old woman was referred to our hospital for a left renal AML. Computed tomography (CT) in our hospital showed a left adrenal mass (25 x 20 mm). Because the adrenal tumor was nonfunctioning, she was followed at outpatient clinic. Four years later, CT showed an increase in the left adrenal tumor size (42 x 30 mm) and a left RCC. Left adrenectomy and partial nephrectomy for RCC and AML were simultaneously performed. Histological examination revealed adrenal SFT and clear cell carcinoma and AML of the kidney. We present a brief review on histological characteristics of retroperitoneal SFT and its occurrence in the adrenal grand region.     

Malignant transformation of renal angiomyolipoma: a case report

We report a case of renal angiomyolipoma (AML) with malignant transformation. A 28-year-old woman developed large bilateral renal masses 5 months before admission to our hospital. She was diagnosed with tuberous sclerosis when she was 4 years old. Total nephrectomy of the left kidney was performed, but she died during the operation. Although the focal region of the resected tumor had the appearance of a classic AML, most of the lesion showed a diffuse proliferation of atypical epithelioid cells resembling that in renal cell carcinoma. The epithelioid cells had extremely pleomorphic and hyperchromatic nuclei with frequent mitotic figures, including atypical forms. Immunohistochemical analysis revealed that the atypical epithelioid cells and the typical AML lesions were both positive for HMB-45 but that the former were negative for epithelial and myogenic markers. The smooth muscle cells and thick-walled vessels were focally positive for muscle-specific actins. Furthermore, the atypical epithelioid cells were immunoreactive for p53, whereas the foci of the typical AML were negative. Examination of the microdissected paraffin-embedded tissues revealed p53 mutations in the malignant epithelioid areas in AML but not in the renal parenchyma or typical AML areas. In this case it is proposed that p53 mutation may play an important role in malignant transformation of renal AML.     

The use of the Ki-67 marker in the pathological diagnosis of the epithelioid variant of renal angiomyolipoma

Objective:  Epithelioid angiomyolipoma (EAML) is a rare malignant variant of renal angiomyolipoma (AML). There were 34 cases of EAML reported in 25 studies (including this present study) over the past decade. About 68% were females and 32% males. The mean age was 40.1 years, 53% developed metastatic disease after nephrectomy, and eight patients had TSC. All cases are reported positive when stained with HMB-45 which also labels all classical AML. This study evaluates the use of Ki-67 (proliferation marker) in the pathological diagnosis of EAML and distinction from classical AML. Method:  Immunohistochemical reactions for Ki-67 were generated on multiple representative blocks of tissue obtained from two cases of HMB-45 positive EAML and four cases of classic AML and the percentage of positively staining cells estimated. Results:  Both cases of EAML were strongly positive for Ki-67 while all four classic AML were completely negative. Conclusion:  The Ki67 is a useful marker in which distinguishes the malignant epithelioid variant of AML from classic AML.     

Clinical presentation of epithelioid angiomyolipoma

OBJECTIVE: Epithelioid angiomyolipomas (AML) of the kidney are malignant tumors with aggressive clinical behavior. METHODS: We reviewed cases of epithelioid AML recently diagnosed at our institution to highlight the spectrum of clinical presentations. RESULTS: In all cases, renal lesions seen on computed tomography were suspicious for renal cell carcinoma (RCC). Histologically, these tumors can resemble RCC. The diagnosis of epithelioid AML was established by positive staining for melanoma and smooth muscle cell markers, and presence of perivascular epithelioid cells. One patient presented with a renal tumor extending into the inferior vena cava to the level of the hepatic veins. Two patients developed recurrent, metastatic disease following nephrectomy. One patient with tuberous sclerosis and multiple, bilateral AML developed an enhancing renal tumor that did not contain any fat densities. A partial nephrectomy was performed and pathology revealed epithelioid AML adjacent to conventional AML. CONCLUSIONS: These tumors are distinguished from RCC by positive immunostaining for melanoma markers and smooth muscle cell markers. They resemble conventional RCC on imaging. Epithelioid AML may be locally aggressive and metastasize.     

PEComa in the rectum: A case report and review of the literature on epithelioid angiomyolipoma

Introduction and importancePerivascular epithelioid cell tumor (PEComa), especially angiomyolipoma (AML) is a rare mesenchymal tumor in wide array of anatomic locations such as the kidney, lung, uterus, and gastrointestinal tract. AML is commonly found in the kidneys and classified as a classic AML or epithelioid AML. We report a case of epithelioid AML diagnosed in the rectum, treated by robot assisted low anterior resection.Presentation of caseA 45-year-old woman was referred to our hospital because when an intramural rectal mass was detected on a colonoscopic examination performed during a regular health checkup. Colonoscopic examination revealed an intramural mass, 2 cm in diameter, bulging in the rectal wall, 6 cm from the anal verge. Based on abdominal and pelvic computed tomography images and magnetic resonance imaging findings, the patient was suspected of having gastrointestinal stromal tumor of the rectum. The patient was treated by robot assisted low anterior resection under the diagnosis of GIST. The patient improved without any postoperative complication and was diagnosed as epithelioid AML, a type of PEComa.DiscussionAML diagnosed in gastrointestinal tract is very rare and among them, epithelioid AML has possibility of malignancy. However, confirmed diagnosis before surgical resection is difficult because PEComa shows nonspecific imaging characteristics. Treatment of choice of epithelioid angiomyolipoma is surgical resection.ConclusionBecause epithelioid AML has the potential for malignancy, clinicians must be aware of the knowledge of the characteristics and natural history of epithelioid AML.     

Renal angiomyolipoma with liposarcomatous transformation: a case report and review of the literature

Renal angiomyolipoma is generally benign, although an uncommon subtype (epithelioid angiomyolipoma) may behave more aggressively. Sarcomatous transformation of the disease is exceedingly rare. We report the first case of a high grade round cell liposarcoma arising in a renal angiomyolipoma.     

Malignant epithelioid angiomyolipoma ('sarcoma ex angiomyolipoma') of the kidney: a case report and review of the literature

Malignant epithelioid angiomyolipoma is a recently described rare tumor of the kidney. Its existence has been questioned, however, on the basis of incomplete evidence of malignant behavior, the absence of an associated classic angiomyolipoma component, or the absence of immunoreactivity for HMB-45 in some cases. We describe a case that was HMB-45-positive and arose in association with a classic angiomyolipoma. The patient was treated with a partial nephrectomy. Three years later, she developed rapidly enlarging liver nodules. A fine-needle aspiration of the liver confirmed the presence of pleomorphic epithelioid cells morphologically and immunohistochemically identical to those comprising the primary renal tumor. After two cycles of treatment with doxorubicin, there was a 50% reduction in the size of the tumors with marked improvement in performance status. We believe this case confirms the existence of a malignant epithelioid angiomyolipoma.     

Malignant epithelioid renal angiomyolipoma involving the inferior vena cava in a patient with tuberous sclerosis

Renal angiomyolipomas (AMLs) are mesenchymal tumors that occur either sporadically or are associated with tuberous sclerosis, and are generally considered to be benign. Malignant AML is extremely rare, and most are found to be epithelioid histopathologically. The authors report the case of a patient followed for renal AML. On CT surveillance, this lesion developed features of a malignant tumor involving the renal vein and inferior vena cava. The patient was treated by nephrectomy and tumor thrombectomy with retroperitoneal lymph node dissection. Histological examination demonstrated renal AML with a malignant epithelioid contingent. The various aspects of this histological and radiological variant are discussed.     

Renal epithelioid angiomyolipoma associated with hyperprolactinemia

We report a unique case of a 42-year-old woman with a renal epithelioid angiomyolipoma associated with elevated serum prolactin levels and presenting with galactorrhea. Magnetic resonance imaging of the brain showed no pituitary abnormality, and abdominal imaging demonstrated a large right renal mass. Pathologic analysis of the radical nephrectomy specimen revealed an epithelioid angiomyolipoma. She had an uneventful postoperative recovery with complete normalization of her serum prolactin level and resolution of galactorrhea. To our knowledge, the association between epithelioid angiomyolipoma and hyperprolactinemia has never before been reported.     

Renal angiomyolipoma in Japanese tuberous sclerosis patients

Purpose

Renal angiomyolipoma (AML) is a benign neoplasm that may grow massive in tuberous sclerosis (TS) patients. The aim of this study was to document the characteristics of renal AML in Japanese TS patients.

Methods

Medical records of 29 TS patients followed up at the authors’ center were reviewed for the presence, size, symptom, and treatment of renal AML.

Results

Twenty-four patients screened for renal AML were subdivided into 4 groups: group 0 (n = 8), no mass; group 1 (n = 5), AML less than 1 cm in diameter; group 2 (n = 4), AML 1 to 4 cm in diameter; group 3 (n = 7), AML greater than 4 cm in diameter. When present, AML always affected both kidneys and were multiple. All patients in groups 1 and 2 were symptom free, and the tumors seemed stable in size. All tumors in group 3 grew progressively causing various symptoms. Total or partial nephrectomy or transarterial embolization was performed in 5 patients with limited success.

Conclusions

AML in TS patients can be stable or aggressive. Pediatric surgeons aware of this problem should be involved in a follow-up program.     

Variants of renal angiomyolipoma closely simulating renal cell carcinoma: difficulties in the histological diagnosis

Renal angiomyolipoma is considered to be a benign renal tumor composed of atypical blood vessels, smooth muscles and fat cells. We report 2 cases of unilateral renal angiomyolipoma. In both cases, our preoperative diagnosis was renal cell carcinoma, because no low density area compatible with fat tissue was noted in the tumors on radiographic evaluation. Through histological examination, both tumors proved to be angiomyolipomas mainly composed of epithelioid cells in 1 case, and spindle-shaped smooth muscle cells mimicking a leiomyoma in the other case. Both patients are well showing no evidence of metastases 16 and 14 months after nephrectomy, respectively.     

Renal epithelioid angiomyolipoma presenting clinically as renal cell carcinoma – A case report

We describe a 22-year old female who presented with a 5-year history of a palpable, painless mass in the right flank. Computerized tomography demonstrated a solid renal mass measuring 18 cm × 13 cm with peripheral calcification, areas of vascularity and necrosis. The appearance suggested renal cell carcinoma or nephroblastoma, but percutaneous renal biopsy suggested an adrenal origin. At right radical nephrectomy, the adrenal gland was completely normal. Histology showed sheets and nests of epithelioid cells with abundant eosinophilic to clear cytoplasm, confirming a diagnosis of epithelioid angiomyolipoma (EAML), a rare mesenchymal tumor belonging to the perivascular epithelioid cell tumor family (PEComas). At 33 months followup, there was no evidence of recurrence or metastases.     

Vaginal mass with urinary incontinence: a rare presentation

To our knowledge, there are only few published cases of benign renal AML presenting with tumor thrombus in females. We present a new case of this uncommon complication of a benign renal tumor.Epithelioid angiomyolipoma is a recently described rare variant of renal angiomyolipoma.It can occur in patients with or without tuberous sclerosis, and may potentially bemalignant. Benign renal angiomyolipoma (AML) rarely presents with evidence of extension into the renal vein, inferior vena cava (IVC) or atrium. We report a case of a benign renal AML with a tumor thrombus extending into the IVC in a 46-year-old female who presented with right-sided flank pain associated with a right sided abdominal mass. Right Radical nephrectomy with IVC tumor thrombectomy was done. Patient is totally asymptomatic. At 1 month after surgery, an abdominal ultrasound showed no evidence of thrombus within the IVC. CT scan of the abdomen at 3 months post-operatively showed no evidence of recurrence. Surgical treatment of angiomyolipoma with IVC thrombus is warranted in view of risk of malignancy and to prevent tumor embolus to the heart or lungs.     

Tuberose sclerosis and bilateral renal carcinoma

A case report is presented of an 18-year-old girl of normal intellect with tuberose sclerosis and multiple bilateral renal carcinomas. These tumours were successfully treated surgically by right nephrectomy and left partial nephrectomy. The usual renal lesion in these patients is the angiomyolipoma, which is a hamartoma. Renal carcinoma associated with tuberose sclerosis is extremely rare, and the mode of behaviour of these tumours may be unusual.     

经皮消融治疗肾血管平滑肌脂肪瘤应用进展

肾血管平滑肌脂肪瘤(AML)是肾脏良性肿瘤,对有症状或病灶直径4 cm患者,既往推荐采用部分肾切除术和选择性动脉栓塞术进行治疗。近年来,经皮消融疗法用于治疗肾AML,具有对肾功能影响小、并发症少、复发率低等优点,但证据尚不充分。本文主要对射频消融、微波消融和冷冻消融治疗肾AML的研究进展进行综述。     

Renal epithelioid angiomyolipoma with malignant behavior

The patient was a 22-year-old woman with a history of tuberous sclerosis who complained of abdominal distention. Computed tomography showed bilateral renal masses with minimal fat tissue that were unlike classical angiomyolipoma (AML), as well as enlargement of the paraaortic lymph nodes, pleural effusion, and ascites, similar to other advanced malignant neoplasms such as renal cell carcinoma and renal sarcoma. We performed a left nephrectomy to relieve the symptoms. A pathological examination revealed that the tumor was composed of polygonal epithelioid cells positive for both αSMA and HMB-45, as well as spindle-shaped cells, while immunoreactivity proved the tumor to be an eAML, a subtype of AML with malignant potential. Although the patient was scheduled for postoperative adjuvant chemotherapy, her condition worsened and she died on postoperative day 24 before receiving chemotherapy. We discuss this case with reference to previous reports.     

肾上皮样血管平滑肌脂肪瘤诊治探讨

目的 提高肾上皮样血管平滑肌脂肪瘤(EAML)的诊治水平.方法 肾EAML患者5例.男3例,女2例.平均年龄46(26～64)岁.患侧腰部胀痛3例,体检偶然发现2例.肿瘤直径2.9～10.1 cm.B超和CT检查诊断为血管平滑肌脂肪瘤2例,肾癌、肾上腺肿瘤、肝癌各1例.行肾肿瘤剜除术3例,肾楔形切除术1例,肾切除术1例.结果 病理报告:肿瘤由不同比例的异常厚壁血管、平滑肌和脂肪组织构成.上皮样细胞胞质浓密嗜酸性或透亮,有嗜酸性颗粒,并有丰富的血管,上皮样细胞簇常围绕血管.组织学形态表现为圆形、多边形和梭形上皮样细胞灶性分布于脂肪瘤中,上皮样瘤细胞免疫组化标记SMA、Vimentin、HMB45表达阳性.5例病理诊断均为肾EAML.随访2～12个月,未见局部复发及远处转移.结果 肾EAML由厚壁血管、脂肪和平滑肌细胞混合组成,上皮样细胞簇常围绕血管.确诊依赖于临床、影像学及病理学检查相结合,免疫组织化学染色有助于诊断及鉴别诊断.早期诊断及完整切除肿瘤是治疗关键.     

Renal angiomyolipoma complicated by retroperitoneal hematoma

Renal angiomyolipoma (AML) is a benign tumor, they are generally asymptomatic or can manifested by abdominal pain, palpable mass or hematuria. We report an uncommoun case of 65 years old women who consulted for retroperitoneal hemorrhage by spontaneous rupture of renal AML with palpable mass. The ultrasound and CT abdominopelvic scan were performed in the preoperative diagnosis and showed a typical right renal AML with retroperitoneal hematoma. The right nephrectomy by transperitoneal approach was performed with a good follow-up. The histological examination confirmed the diagnosis for renal AML. About this case, the authors discuses the diagnosis and the management for AML with retroperitoneal hemorrhage.     

Retroperitoneoscopic partial nephrectomy by using microwave tissue coagulation

Partial nephrectomy is widely accepted as a treatment for small renal cell carcinoma. However, the laparoscopic approach has not yet been considered as a standard procedure. We reviewed our 13 retroperitoneoscopic partial nephrectomies and 11 conventional open partial nephrectomies. We have used microwave tissue coagulation for retroperitoneoscopic surgery without renal pedicle clamping between December 1999 and May 2003. The mean operating time for the retroperitoneoscopic group was not significantly longer than that for conventional open surgery group (183 minutes vs 194 minutes). However, the mean blood loss for the retroperitoneoscopic group was less than that for the open group (143 ml vs 512 ml). Histologic evaluation revealed renal cell carcinoma in 10 patients, angiomyolipoma in 2 patients, and lymphoangiomyomatosis in one patient for retroperitoneoscopic group and renal cell carcinoma in 11 patients for the conventional open surgery group. In addition, when compared with the historical control that had undergone conventional partial nephrectomy, laparoscopic cases had significantly shorter postoperative times to oral intake, ambulance, and discharge from hospital. Bowel injury, massive bleeding, urine leakage, and atelectasis occurred in one case each in retroperitoneoscopic surgery. Retroperitoneoscopic surgery in the case of massive bleeding was converted to open surgery. On the other hand, urine leakage and postoperative hemorrhage occurred in one case each in conventional open surgery. Retroperitoneoscopic partial nephrectomy by using microwave tissue coagulation is a useful and less invasive method, whereas this procedure is more challenging than open partial nephrectomy in terms of complications.