Renal epithelioid angiomyolipoma with a negative premelanosome marker immunoprofile: a case report and review of the literature (original) (raw)
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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...
Epithelioid Angiomyolipoma of the Kidney
The American Journal of Surgical Pathology, 1997
Epithelioid angiomyolipoma (eAMLoma) is an uncommon renal mesenchymal tumor with malignant potential and is frequently associated with tuberous sclerosis (TSC). It is composed of polygonal large-sized tumor cells arranged in an epithelioid manner. Differential diagnosis from renal cell carcinoma (RCC) is often challenging because of its epithelioid morphology. Herein is reported three cases of eAMLoma, involving one in a 28-year-old man with TSC and two in women without TSC (34 and 62 years of age, respectively). The male TSC patient had microscopic conventional AMLomas in the same kidney. All patients were positive for melanoma (reactive with HMB45 antibody, and positive for melan A, tyrosinase and microphthalmia transcription factor) and smooth muscle markers (positive for a-smooth muscle-specific actin), but not for epithelial markers (cytokeratin, epithelial membrane antigen). In particular, the translocation RCC is an important differential diagnostic candidate, in terms of the positive reaction with HMB45 and morphological similarity. The present tumor samples did not show any reactivity for transcription factor binding to IGHM enhancer 3 or transcription factor EB, which excluded the possibility of translocation RCC. The possibility of eAMLoma should be evaluated as a diagnostic candidate, especially in cases of renal tumors (i) in young patients; (ii) associated with TSC; or (iii) with an epithelioid morphology and a high nuclear grade.
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.
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.
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.
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.
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
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.
Malignant Epithelioid Angiomyolipoma of the Kidney
Journal of the Formosan Medical Association, 2007
Angiomyolipoma (AML) is a common benign renal tumor that is composed of thick-walled blood vessels, smooth muscle, and adipose tissue, but the malignant epithelioid variant is extremely rare. Here, we report a case of a 78-year-old woman who had malignant epithelioid AML with regional lymph node metastases.