Abstract
Sclerosing epithelioid fibrosarcoma (SEF) is an uncommon tumor of the deep soft tissue. It was first described in 1995 by Meis-Kindblom et al. Histologically, this tumor is characterized by uniform, small, round to ovoid epithelioid cells with clear cytoplasm, and the cells are arranged in distinct nests and cords. On immunohistochemistry, the most consistently positive marker is vimentin, although other antigens (cytokeratin, epithelial membrane antigen, S100 protein and neuron specific enolase) have been recorded as being inconsistently positive. We report here on a case of a 46-year-old woman who presented with back pain. The radiologic findings revealed a right renal mass and multiple bone metastases. The patient underwent radical nephrectomy and the pathologic finding was primary SEF of the kidney.
Figures and Tables
Fig. 1
Abdominal CT scan shows a 3cm sized lobulated enhanced solid mass in the upper pole of the kidney.
![kju-48-986-g001](/upload/SynapseData/ArticleImage/1020kju/kju-48-986-g001.jpg)
Fig. 2
Positron emission tomography (PET) shows hypermetabolic lesions in the right kidney (standardized uptake value=3.4), the CT-L-S spines, the ribs and the femur (standardized uptake value=4.1).
![kju-48-986-g002](/upload/SynapseData/ArticleImage/1020kju/kju-48-986-g002.jpg)
Fig. 3
Sagittal section reveals a well demarcated white to tan and firm mass that measured 4.0×3.0×3.2cm at the renal capsule.
![kju-48-986-g003](/upload/SynapseData/ArticleImage/1020kju/kju-48-986-g003.jpg)
Fig. 4
Histologic and immunohistochemistry findings of sclerosing epithelioid fibrosarcoma (SEF). (A) The tumor cells are uniform, small, round to ovoid epithelioid cells with clear cytoplasm, and they are arranged in distinct cords and strands (H&E, ×100). (B) There is positive staining for vimentin. Arrow: positive staining (Vimentin, ×400).
![kju-48-986-g004](/upload/SynapseData/ArticleImage/1020kju/kju-48-986-g004.jpg)
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