Incidentally discovered yellowish lesions in a renal graft from a deceased donor.

ABSTRACT

The opening of Gerota's fascia, soon after harvesting the kidney, is a standard kidney donor procedure in Italy to exclude a renal cell carcinoma (RCC), a frequent finding in older donors. Herein we have reported our experience with the diagnosis and management of subcapsular yellow areas suggestive of RCC on the kidney surface during back-table procedures. From 2001 to 2006, 12/445 grafts showed a single yellowish subcapsular nodule during the back-table procedure which was excised for frozen section (FS) to rule out RCC. The affected donors were 7 males and 5 females of overall mean age of 60 years (range, 25-77 years). The mean nodule diameter was 0.75 cm (range, 0.3-1.2 cm), and all lesions were located in the upper renal pole. In 5 cases, a diagnosis of RCC could not be excluded by FS, and both kidneys were discarded. The final histology confirmed RCC in only 3 cases, and adrenal heterotopia (AH) in the other 2. In the remaining 7 cases, FS showed AH in 4, 1 angiomyolipoma, and 2 areas of infarction confirmed by histology. The adrenal foci consisted of clear cells and scattered cells with eosinophilic, granular cytoplasm and small round nuclei, some with small nucleoli. Immunostains for cytokeratins, CD10, and epithelial membrane antigen were negative, confirming the adrenal origin. AH is the most common pathological yellowish lesion in the upper kidney pole found incidentally during back-table preparation. A histological differential diagnosis with RCC at FS is difficult, relying on the distinction of normal corticoadrenal spongiocytes from Fuhrman grade 1 clear cancer cells. In Italy, for any renal mass suggestive of RCC, a graft discard is mandatory, even if several reports have described cases of renal transplantation performed after back-table excision of small unifocal tumors.