case_images: PMC7582086_01
case_images: Contrast-enhanced CT scan of the abdomen (a) two years before transplant and (b) five months after transplant. (a) Left kidney showing a 3.1 x 2.6 cm, nonenhancing, cystic lesion at the upper pole. (b) Enlarged and minimally enhancing 3.3 x 3.8 cm mass in the upper pole of the left kidney suspicious for renal cell cancer (white arrow).
case_images: CRIN2020-7145652.001.jpg
case_images: PMC7582086_01_CRIN2020-7145652.001.jpg
case_images: fig1
case_images: Bosniak class II renal cyst. Based on these findings, no further follow-up was recommended (Figure 1(a)). Abdominal CT scan revealed an enlarging, minimally enhancing hypodense 3.3 x 3.8 cm cystic mass, Bosniak class IV, in the upper pole of the native left kidney that was suspicious for RCC (Figure 1(b)).
case_images: (a) Well-demarcated lesion of small- to intermediate-sized tubules admixed with cystically dilated tubules (solid thick arrows). (b) Tubules and cysts comprising a single epithelial layer of flat to hobnail-shaped cells with abundant, pink cytoplasm and large nuclei with prominent nucleoli (dashed thick arrows). The stroma was fibrotic and paucicellular, while mitotic activity was low to absent. No papillary architecture or epithelial cell clearing was observed. (c) Immunohistochemical stain for CK7 showed patchy reactivity (thin solid arrows) in the lesional areas. (d) CD10 showed strong reactivity.
case_images: CRIN2020-7145652.002.jpg
case_images: PMC7582086_01_CRIN2020-7145652.002.jpg
case_images: fig2
case_images: Immunohistochemical analysis of the neoplastic cyst-lining cells was positive for racemase, CD10, vimentin, and focal positive staining with CK7, as well as negative staining with EMA (Figure 2).