Epithelioid Angiomyolipoma of the Kidney (original) (raw)
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Renal Angiomyolipoma With Epithelioid Sarcomatous Transformation and Metastases
The American Journal of Surgical Pathology, 2000
Angiomyolipoma (AML) is a benign neoplasm that occurs either sporadically or in patients with tuberous sclerosis complex (TSC) and shows frequent allelic losses at chromosome arm 16p. It has been suggested recently that the melanogenesis marker-positive perivascular epithelioid cell (PEC) has been found consistently in AML. The authors report a 50-year-old woman without evidence of TSC affected by classic renal AML containing an area composed of atypical epithelioid cells with the same morphoimmunophenotypic characters of PEC. After 7 years from surgical removal of the lesion, the patient developed a local recurrence and successive lung and abdominal metastases that showed morphologic and immunohistochemical features overlapping those of the epithelioid area of the previously removed AML. Genetic analysis showed that the classic AML and its epithelioid area as well as the pulmonary and abdominal metastases shared the same allelic loss on chromosome arm 16p. Based on these findings, the authors view this case as evidence of a malignant transformation of a classic AML with morphologic, immunophenotypic, and genetic demonstration of its clonal origin.
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.
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.
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.
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...
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 Angiomyolipoma (AML) is a benign lesion with a variable admixture of fat cells, thick walled blood vessels, smooth muscle and polygonal epithelioid cells. The lesion can be diagnosed with certainty in the presence of all the components on fine needle aspiration, supported by CT findings. However the presence of predominant population of epithelioid cells with paucity or absence of other components can be particularly worrisome, especially if radiological findings are noncontributory. These large cells with low N:C ratio and frothy cytoplasm and anisonucleosis require detailed evaluation and careful search for typical background cytology. Two such cases of AML with a predominant population of epithelioid cells are being described with their cytological and histological findings with a review of literature to highlight the diagnostic dilemma and emphasize the utility of HMB-45 immunostaining in such cases.
Histopathology, 2009
Renal epithelioid angiomyolipoma: a study of six cases and a meta-analytic study. Development of criteria for screening the entity with prognostic significance Aims: Renal epithelioid angiomyolipoma (EAML) is only described in case reports or in multi-institutional small series. The aim was to report cases seen at our institution and to perform a meta-analysis based on a literature review. Methods and results: Six EAML cases seen at our institution were reviewed and a meta-analysis performed using cases retrieved from a literature review. There were a total of 69 cases for review. The male:female ratio was 1:3. In the absence of areas of typical AML, useful features in distinguishing EAML from epithelial renal neoplasms include: extreme degree of cytological atypia, histiocytoid appearance, presence of melanocytic pigments, solid architecture with the absence of frequent areas of alveolar pattern, tubulo-papillary formation and scarring. A fatal outcome, distant or lymph node metastasis, venous invasion and local recurrence were considered as adverse events and occurred in 40% of cases over a period of follow-up of 3-60 months (mean 22.5 ± 18 months). Tumours with an unfavourable outcome showing marked cytological atypia and extensive tumour necrosis were larger (135 ± 43 mm) than those with a favourable outcome (79 ± 50 mm) (P < 0.002), and predominantly occurred in men. Conclusions: Renal neoplasms with certain unusual features should be investigated immunohistochemically to rule out the possibility of EAML. The frequency of adverse outcome is lower in EAML than in renal cell carcinoma.
Diagnostic pitfall of a rare variant of angiomyolipoma, epithelioid angiomyolipoma - a case report
Pan African Medical Journal, 2020
Angiomyolipoma of the kidney is a common benign mesenchymal neoplasm of kidney. A rare variant, epithelioid angiomyolipoma, however, may show malignant behavior. We report a case of epithelioid angiomyolipoma in a patient not having tuberous sclerosis which was initially misdiagnosed as renal cell carcinoma. A 39-year-old woman presented with a history of flank pain. Ultrasonography revealed a left renal mass. Contrast-enhanced computed tomography (CECT) abdomen revealed mass involving hilum of the kidney. On core biopsy a possibility of renal cell carcinoma was suggested. The patient underwent radical nephrectomy. After immunohistochemical analysis, a final diagnosis of epithelioid angiomyolipoma was made. Renal epithelioid angiomyolipoma without adipocytic component is extremely rare. It is pivotal to keep a possibility of epithelioid angiomyolipoma whenever an epithelioid renal tumor is encountered showing marked pleomorphism and mitosis. The use of melanocytic markers and specific markers of renal cell carcinoma will aid the diagnosis.