PMC4719503_01
Initial 9 cm right renal cyst
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F1
A computed tomography (CT) scan of the abdomen and pelvis renal mass protocol showed a 9 cm mass with fluid density and very thin intracystic septations representing a Bosniak II cyst in her right kidney [Figure 1].
Paracolonic cystic lesion (white arrow) along the ascending colon in relation to recurrent right renal mixed epithelial stromal tumor cyst (red arrow)
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F2
Interestingly, she was also found to have multiple cystic lesions near the ascending colon with similar radiologic features as the renal cyst suspicious for MEST deposits [Figure 2].
Mesenteric multiloculated paracolonic mixed epithelial stromal tumor lesion (arrows)
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F3
Then she underwent an excision of cystic multiloculated mesenteric lesion that was attached to the ascending colon [Figure 3] by the colorectal team using Endo GIA  stapler.
H and E stain of the renal cyst showing dense fibrous, loose, smooth muscle, hypercellular spindled, and ovarian stroma-like elements (x40)
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F4
The stroma was composed of areas of dense fibrous, loose, smooth muscle, hypercellular spindled, and ovarian stroma-like elements [Figure 4].
Immunohistochemical stain of stroma is positive for estrogen receptor (x200)
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F5