Oncocytic papillary renal cell carcinoma with inverted nuclear pattern: Distinct subtype with an indolent clinical course
ABSTRACT Reported herein are seven cases of a histologically distinct oncocytic papillary renal cell carcinoma (OPRCC) with an inverted nuclear pattern. To define its prognostic significance, the clinicopathological features of OPRCC were compared to those of types 1 and 2 PRCC. The median age of the seven patients was 67 years. Grossly, tumors were well-circumscribed and small (1.2 cm +/- 0.4 cm). Microscopically, the OPRCC were composed of well-developed thin papillae, lined with a single layer of cuboidal-to-columnar oncocytic cells. The tumor cells had round-to-oval nuclei and eosinophilic granular cytoplasm, which was strongly positive for anti-mitochondrial immunostaining. The nuclei were characteristically polarized toward the surface of the papillae and contained mostly small nucleoli. The tumors had high expression of alpha-methylacyl-coenzyme A racemase, CD15, CD117, cytokeratin (CK) 7, E-cadherin, epithelial membrane antigen, MOC 31, mucin-1, vascular endothelial growth factor and vimentin, low expression of CD10 and Ki-67, and no expression of CK20. Genetically, gain of chromosomes 3p, 11q, and 17q, and loss of chromosome 4q was observed. All seven patients were alive with no recurrence or metastasis at a mean follow-up time of 37.1 +/- 23.7 months. In conclusion, OPRCC show unique pathological features with indolent clinical behavior and are more similar clinicopathologically to type 1 than to type 2 PRCC.
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ABSTRACT: OBJECTIVE. The objective of our study was to determine the frequency of atypical papillary renal cell carcinomas (RCCs) and identify imaging differences between type 1 and type 2 papillary RCCs once atypical papillary RCC tumors have been excluded. MATERIALS AND METHODS. Eighty-two papillary RCC tumors were classified at pathology as type 1, type 2, or atypical. The CT and MRI examinations of these tumors were reviewed. Imaging features such as tumor size, margins, heterogeneity, and enhancement were assessed and the findings in type 1 and type 2 tumors were compared. RESULTS. There were 43 type 1 and 13 type 2 tumors. Atypical histologic features (i.e., tumors containing both type 1 and type 2 components, clear cells, or components with atypically high nuclear grade [in type 1 tumors] or low nuclear grade [in type 2 tumors]) were seen in 26 tumors. On CT, type 2 tumors more commonly had infiltrative margins (p = 0.05) and were more likely to have calcifications (p = 0.04) than type 1 tumors, although these features were seen in all tumor types. Type 2 tumors were also more heterogeneous than type 1 tumors (p = 0.04). On CT, 11 papillary RCCs showed enhancement of less than 20 HU, seven of which showed enhancement of less than 10 HU. On MRI, all tumors showed enhancement on subtraction images. CONCLUSION. Nearly one third of papillary RCCs in our patient population had atypical features at histology. On CT and MRI, there are some significant differences in imaging features between type 1 and type 2 tumors; however, substantial overlap precludes categorization on a per-patient basis. On CT, many papillary RCCs do not enhance, indicating that assessment of enhancement alone is insufficient for differentiating papillary RCCs from hyperdense cysts.American Journal of Roentgenology 08/2013; 201(2):347-55. DOI:10.2214/AJR.12.9451 · 2.74 Impact Factor
Value in Health 11/2005; 8(6). DOI:10.1016/S1098-3015(10)67438-4 · 2.89 Impact Factor
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ABSTRACT: We investigated the role of fluorescence in situ hybridization (FISH) in the diagnosis of primary renal neoplasms and lesions suspicious for metastatic renal cell carcinoma. Consecutive fine-needle aspiration biopsies (FNAB) of 39 renal masses and 41 metastatic tumours suspicious for renal cell origin were assessed with an immunohistochemical panel for CK7, RCC antigen, CD10, AMACR, PAX8, vimentin, and CD117. In addition, FISH was performed using probes for chromosomes 1p, 3p, 7, 17, X, and Y. A total of 31 of 39 primary renal masses and 33 of 41 metastatic tumors suspicious for renal origin demonstrated typical cytological and immunohistochemical (IHC) features of subtypes of renal neoplasms (40 clear cell renal cell carcinoma (RCC), 20 papillary RCC, and 4 renal oncocytomas). FISH analysis of 15 randomly selected cases each of primary and metastatic lesions revealed chromosomal abnormalities consistent with the diagnosis in 73% of these cases. Of 8 primary renal masses demonstrating atypical microscopic features and noncontributory IHC profiles, FISH was helpful in subtyping 5 (62%) of these lesions (2 clear cell RCC, 1 solid variant of oncocytic papillary RCC, 1 mixed clear cell and papillary RCC, and 1 chromophobe RCC with papillary architecture). Of 8 metastatic tumors clinically suspicious for renal cell origin and supportive, but nondiagnostic IHC, FISH revealed supportive chromosomal changes in 6 (75%) cases. In conclusion FISH analysis on FNAB material, even with limited tissue, may be contributory to the diagnosis and subtyping of RCC in diagnostically challenging biopsies. Diagn. Cytopathol. 2014. © 2014 Wiley Periodicals, Inc.Diagnostic Cytopathology 12/2014; 42(12). DOI:10.1002/dc.23154 · 1.52 Impact Factor