PMC5654276_01
(a) Computed tomography scan coronal section demonstrates an enhancing, round lesion, suspicious for malignancy in the mid renal zone (arrow). (b) Embolization of the renal artery of the renal allograft was performed before graft nephrectomy.
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Abdominal computed tomography (CT) scan showed 1.8 cm enhancing lesion in the middle third of renal allograft (Figure 1(a)). Later, the patient was admitted electively and underwent embolization of the renal artery of the renal allograft (Figure 1(b)) and graft nephrectomy.
(a) Histopathological examination of the renal allograft tumour showed eosinophilic chromophobe renal cell carcinoma. The tumour consisted of medium to large round and polygonal neoplastic cells arranged in variably sized nests and cords and poorly formed acini [H&E x200]. (b) Tumour cells exhibited hyperchromatic nuclei, irregular "raisinoid" nuclear membranes (arrows) and voluminous, and dense eosinophilic cytoplasm [H&E x400]. (c) Tumour cells "raisinoid," wrinkled nuclear membranes, and perinuclear cytoplasmic clearing (arrows) [H&E x600]. Immunophenotypically, the tumour cells exhibited positive immune reaction to pancytokeratin (CK) (d), low-molecular weight CK (e), CK7 (diffuse and strong staining, (f)), and E-cadherin (g), while staining for renal cell carcinoma (h), CD10 (i), and CD117 (j) antibodies was negative [(d-j) x200].
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The tumour consisted of medium to large, round, and polygonal neoplastic cells that exhibited mild degree of nuclear pleomorphism and arranged predominantly in variably sized nests, cords, and poorly formed acini and had hyperchromatic nuclei, indistinct nucleoli, irregular "raisinoid" or round nuclear cell membranes, abundant amount of dense eosinophilic cytoplasm, and poorly defined cell membranes (Figures 2(a)-2(c)). Scattered binucleated cells and occasional neoplastic cells with pale cytoplasm and perinuclear cytoplasmic clearing were present (Figure 2(c)). Immunohistochemically, the neoplastic cells exhibited diffuse positive cytoplasmic staining for pancytokeratin (CK), low-molecular weight CK (CK8/18), CK7, and epithelial membrane antigen (EMA), and membranous staining for E-cadherin (Figures 2(d)-2(g)), while IHC staining for vimentin, CD10, CD117, and renal cell carcinoma (RCC) marker was negative (Figures 2(h)-2(j)).