Renal Epithelioid Angiomyolipoma with Aggresive Progression: A Case Report and Literature Review (original) (raw)

ANGIOMYOLIPOMA OF KIDNEY – A CASE REPORT

Angiomyolipoma belongs to a family of neoplasms called perivascular epithelioid cell tumors (PEComas). The World Health Organization (WHO) defines PEComas as " mesenchymal tumors composed of histologically, ultra structurally, and immunohistochemically distinctive perivascular epithelioid cells. Renal angiomyolipoma is an uncommon benign tumor characterized by a variable mixture of adipose tissue, smooth muscle and thickened blood vessel and perivascular epithelioid cells also known as PEComa. Microscopically, the tumor shows mature adipose tissue, tortuous thick-walled blood vessels lacking elastic tissue lamina, and bundles of smooth muscle that seem to emanate from the vessel wall. A 55 year old male patient presented with a huge abdominal painful lump in left hypochondrium. Clinicoradiological evaluation suggests a mass lesion arising from kidney. Nephrectomy was carried out. Cut section of kidney showed multiple nodular yellow white and brown areas. Random sections from growth showed admixture of Spindle cells & adipose tissue along with thick walled blood vessel. Immunohistochemistry was carried out the result of which showed HMB 45 and Smooth Muscle Actin positive, but cytokeratin was negative. Considering the unilaterality, unifocality, larger size of the tumor and microscopic finding, and IHC result, the case was confirmed as sporadic angiomyolipoma.

An unusual appearance of renal epithelioid angiomyolipoma

Singapore medical journal, 2012

Epithelioid angiomyolipoma is a recently described rare variant of renal angiomyolipoma. It can occur in patients with or without tuberous sclerosis. We report the imaging findings of a case of epithelioid angiomyolipoma that showed the presence of fatty tissue undifferentiated from the typical angiomyolipoma at the beginning. After partial nephrectomy, tumour recurrence occurred two years later, presenting as completely solid tumours with no adipose tissue, and with invasion into the psoas muscle and left adrenal gland. Differentiation of this tumour from renal cell carcinoma is difficult. Both the radiologist and surgeon should be aware of the existence of this tumour and its potentially malignant behaviour.

Renal Epithelioid Variant of Angiomyolipoma -A Rare Case Report

https://www.ijrrjournal.com/IJRR\_Vol.6\_Issue.8\_Aug2019/Abstract\_IJRR0011.html, 2019

Epithelioid Angiomyolipoma (EAML) is a rare mesenchymal tumour with malignant potential. The epithelioid variant of angiomyolipoma was first described in 1995 by Martignoni et al as a distinct clinicopathologic variant of AML which is mainly characterized by a predominance of epithelioid cells. Histologically, EAML is characterized by sheets or nests of large polygonal epithelioid cells with abundant eosinophilic or occasionally clear cytoplasm, often with prominent nucleoli, including multinucleated and markedly pleomorphic forms. These tumours share a distinctive perivascular epithelioid cell phenotype; they belong to the PEComa tumour family. Nearly all EAMLs show immunoreactivity for both melanocytic and myoid markers. EAML can pose significant diagnostic challenge on H and E microscopy as it morphologically mimics a variety of neoplasms. An EAML diagnosed by the authors in an adult male patient is presented here.

Massive Malignant Epithelioid Angiomyolipoma of the Kidney

Journal of Kidney Cancer and VHL

Renal angiomyolipomas (AMLs) are a subset of perivascular epithelioid cell neoplasms (PEComas) that are associated with tuberous sclerosis complex (TSC). Epithelioid angiomyolipomas (EAMLs) are a rare variant of AML with more aggressive propensities. EAMLs with malignant potential can be difficult to distinguish from relatively benign AMLs and other renal tumors. Although there are no established criteria for predicting EAML malignancy, there are proposed histologic parameters that are associated with higher tumor risk. EAML can be treated with surgical resection as well as mTOR inhibitors. Here, we present a unique case of a patient with a 36-cm renal EAML metastatic to the lungs that was treated with complete surgical resection of the primary lesion and mTOR inhibition.

Epithelioid angiomyolipoma of the kidney: case report

Pathologica, 2008

Renal angiomyolipoma is a benign tumour histologically characterized by a mixture of adipose tissue, smooth muscle cells and thick walled blood vessels. Long-believed to be a benign hamartoma, angiomyolipoma is now considered to arise from perivascular epithelioid cells. Epithelioid angiomyolipoma is a rare type of angiomyolipoma, composed partially or completely of epithelioid cells, with a potentially aggressive behaviour. Histologically it can mimic renal cell carcinoma. Positivity for HMB45, Melan A, CD68 and CD117 are useful for diagnosis. Herein, we report the clinicopathologic and immunohistochemical features of a renal tumour composed of large epithelioid mononucleated or multinucleated cells with abundant acidophilic cytoplasm and prominent nucleoli. Despite the morphologic resemblance of this tumour to renal cell carcinoma, its phenotype (HMB45, Melan A and CD68 positivity and keratin negativity) parallels the phenotypic profile of angiomyolipoma. Therefore, immunohistoche...

Clinical presentation of epithelioid angiomyolipoma

International Journal of Urology, 2007

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.

A Renal Angiomyolipoma with Epithelioid Features: A Case Report

The epithelioid variant of angiomyolipomas has been documented to have the ability to behave in an aggressive manner. We report a 38-year-old woman who presented with progressive left flank pain for several months. A renal angiomyolipoma with hemorrhage was diagnosed with an imaging study, and she underwent surgical removal due to persistent symptoms. Epithelioid features were observed in the histologic examination. Positive immunostaining for HMB-45 further supported the diagnosis. Although the postoperative period in this patient was uneventful after 9 months of follow-up, regular postoperative surveillance is significant in light of the malignant potential of epithelioid