Renal mixed epithelial and stromal tumor: case report

Karla Lais Pêgas,Júlia M Zanatta,Antônio A Hartmann,Giovani Thomaz Pioner,Suzana Elisabeth Lamonatto,Kárita Guimarães,Roque D Furian,Eduardo Cambruzzi,Elizete Keitel

doi:10.5935/1676-2444.20150008

Karla Lais Pêgas, Júlia M Zanatta + Show 7 more

Open Access

https://doi.org/10.5935/1676-2444.20150008

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Abstract

Mixed epithelial and stromal tumor (MEST) represents a recently described biphasic kidney neoplasm, which predominantly affects perimenopausal females. The authors report the case of a young male patient with a MEST exhibiting positivity for estrogen and progesterone receptors. Computed tomography/magnetic resonance imaging (CT/MRI) showed an expansive lesion affecting the right kidney. Grossly, a solid-cystic tumor was identified, which measured 5.7 × 3.5 × 2.4 cm. On microscopic examination, a biphasic tumor constituted by stromal and epithelial elements, without significant atypias, was identified. The stromal element was composed of spindle cells revealing positive immunoexpression for actin, desmin, vimentin, and estrogen receptors. The epithelial component exhibited a predominantly tubular pattern showing positive immunoreaction for cytokeratins. The diagnosis of MEST was then established.

Highlights

Case reportTumors of the kidney amount to 2% of the total human cancer burden, and renal cell carcinoma represents, on average, over 90% of all malignances of the kidney
The authors report the case of a male patient with a Mixed epithelial and stromal tumor (MEST) exhibiting positive immunoexpression of estrogen and progesterone receptors, and discuss clinical and morphologic findings of this uncommon tumor
The stromal element was composed of spindle cells arranged in short fascicles (Figure 2), and varying from hypocellular to fibrotic areas

Summary

Case report

Tumors of the kidney amount to 2% of the total human cancer burden, and renal cell carcinoma represents, on average, over 90% of all malignances of the kidney. Mixed epithelial and stromal tumor (MEST) is a complex renal neoplasm composed of a mixture of stromal and epithelial elements[1,2,3]. The authors report the case of a male patient with a MEST exhibiting positive immunoexpression of estrogen and progesterone receptors, and discuss clinical and morphologic findings of this uncommon tumor.

Discussion

Total nephrectomy Total nephrectomy

Findings

EMA receptor