Renal Angiomyoadenomatoid Tumor (original) (raw)

Renal angiomyoadenomatous tumor (RAT): a rare distinct entity with diagnostic challenges—a case report

Journal of the Egyptian National Cancer Institute, 2021

BackgroundRenal angiomyoadenomatous tumor (RAT) is a recently described rare renal neoplasm with variations in the presentation, gross, and microscopic findings, and having a benign course and good prognosis. It is characterized microscopically by the admixture of three components—epithelial cells arranged in tubules and nests, angiomyomatous stroma, and capillary-sized interconnecting vascular channels in close association with the epithelial cell clusters. Microscopically, these tumors can be confused with clear cell carcinoma, papillary carcinoma, mixed epithelial and stromal tumors, and angiomyolipoma. RAT differs from conventional clear cell carcinomas, which can rarely be associated with an identical leiomyomatosis stroma occasionally forming abortive vascular structures. RAT is a distinct morphologic entity, being different morphologically, immunohistochemically, and genetically from all renal tumors including conventional clear cell carcinoma and mixed epithelial and stromal...

Clear cell renal cell carcinoma with focal renal angiomyoadenomatous tumor-like area

Annals of Diagnostic Pathology, 2011

Recently, renal angiomyoadenomatous tumor (RAT) has been identified. However, there are no descriptions about clear cell renal cell carcinoma (RCC) with focal RAT-like features. A 33-year-old Japanese man was found to have a tumor in the left kidney. Macroscopically, the tumor extended into the perinephric fat tissue, and the cut surface showed the yellowish color. The histologic examination of the tumor consisted of 2 components of clear cell RCC and RAT-like area. The RATlike area showed the admixture of epithelial cells with basophilic or clear cytoplasm and stromal component containing leiomyomatous stroma, fine capillary network, and pericytic network. Immunohistochemically, epithelial neoplastic cells in RAT-like area were diffusely positive for CD10 and RCC Ma. G-band karyotype showed the structural abnormality of chromosome 3 and both components of clear cell RCC and RAT-like area revealed the identical VHL gene mutation. Finally, pathologists should pay attention to the presence of clear cell RCC focally resembling RAT.

Recurrent renal epithelioid angiomyolipoma

Urology, 2003

Renal angiomyolipoma has traditionally been considered a benign tumor. Recently, a variety of epithelioid angiomyolipomas with malignant potential have been described. We report an adrenal recurrence in a patient who had a cellular angiomyolipoma removed 4 years earlier. UROLOGY 61: 1035iii-1035v, 2003.

Renal epithelioid angiomyolipoma mimicking urothelial carcinoma of the upper urinary tract

Archivio Italiano di Urologia e Andrologia, 2014

Epithelioid angiomyolipoma is a rare mesenchymal tumor arising mainly in the kidney that can potentially behave aggressively. Epithelioid angiomyolipoma can often resemble sarcomatoid renal cell carcinoma, high grade renal carcinoma or sarcoma. Its similarity to renal cell carcinoma has been emphasized in most of the cases reported in literature. With the purpose of contributing to the awareness of this similarity, a 32-year-old female patient with renal epitelioid angiomyolipoma in the left kidney which radiologically mimicked urothelial cell carcinoma of the upper urinary tract is presented.

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.

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.

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...

Renal cell carcinoma with areas mimicking renal angiomyoadenomatous tumor/clear cell papillary renal cell carcinoma

Human Pathology, 2013

We present a cohort of 8 renal carcinomas that displayed a variable (5%-95% extent) light microscopic appearance of renal angiomyoadenomatous tumor/clear cell papillary renal cell carcinoma (RAT/CCPRCC) without fulfilling the criteria for these tumors. All but 1 case predominantly (75%-95% extent) showed histopathologic features of conventional clear cell renal cell carcinoma. In 5 of 7 cases with mostly conventional clear renal cell carcinoma (CRCC) morphology, a diagnosis of CRCC was supported by the molecular genetic findings (presence of von Hippel-Lindau tumor suppressor [VHL] mutation and/or VHL promoter methylation and/or loss of heterozygosity [LOH] for 3p). Of the other 2 cases with predominantly characteristic CRCC morphology, 1 tumor did not reveal any VHL mutation, VHL promoter methylation, or LOH for 3p, and both chromosomes 7 and 17 were disomic, whereas the other tumor displayed polysomy for chromosomes 7 and 17 and no VHL mutation, VHL promoter methylation, or LOH for 3p. One tumor was composed primarily (95%) of distinctly RAT/CCPRCClike morphology, and this tumor harbored a VHL mutation and displayed polysomy for chromosomes 7 and 17. Of the 5 cases with both histomorphologic features and molecular genetic findings of CRCC, we detected significant immunoreactivity for α-methylacyl-CoA racemase in 2 cases and strong diffuse www.elsevier.com/locate/humpath ☆ The authors declare that they have no conflict of interest.

Renal epithelioid angiomyolipoma: a study of six cases and a meta-analytic study. Development of criteria for screening the entity with prognostic significance

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.