Oncocytic papillary renal cell carcinoma with solid architecture: mimic of renal oncocytoma.
Papillary renal cell carcinoma (PRCC) can display extensive areas of solid and non-papillary architecture and extensive areas with oncocytic cytoplasm. Eleven oncocytic renal cell neoplasms (ORCN) with histopathological features posing a diagnostic problem between renal cell carcinoma (RCC) with oncocytic features and renal oncocytoma (RO) were identified. The neoplasms were well circumscribed or encapsulated tumors with solid and diffuse growth pattern. Very occasional papillae were seen in four and tumoral necrosis in two of 11. Six ORCN displayed a CD117+/progesterone receptor (PR)+ immunophenotype (feature shared by RO) and five tumors displayed a CD117-/PR- immunophenotype (feature shared by RCC). The CD117-/PR- ORCN also displayed alpha-methylacyl-coenzyme A racemase and RCC antigen reactivity as well as varying reactivity for cytokeratin 7, vimentin and CD10 (features of oncocytic PRCC). These five cases had tumor sizes ranging from 1 to 6 cm. Two patients in the latter group developed progression of the disease with metastases. In conclusion, oncocytic PRCC with solid architecture is a rare type of RCC. The carcinoma often poses differential diagnostic problems with RO and has similar immunohistochemical properties to the common type of PRCC. Cytogenetic and molecular studies have not been performed yet for this variant of RCC.
Mai
Kien T
KT
Division of Anatomical Pathology, Department of Laboratory Medicine, The Ottawa Hospital, University of Ottawa, Ottawa, Ontario, Canada. ktmai@ottawahospital.on.ca
Kohler
Derek M
DM
Robertson
Susan J
SJ
Belanger
Eric C
EC
Marginean
E Celia
EC
D018249:Adenoma, Oxyphilic / Q000175:diagnosis*; D014408:Biomarkers, Tumor / Q000032:analysis; D002291:Carcinoma, Papillary / Q000737:chemistry / Q000175:diagnosis* / Q000556:secondary; D002292:Carcinoma, Renal Cell / Q000737:chemistry / Q000175:diagnosis* / Q000556:secondary; D003937:Diagnosis, Differential; D006801:Humans; D007124:Immunoenzyme Techniques; D007680:Kidney Neoplasms / Q000737:chemistry / Q000175:diagnosis*; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis; D011980:Receptors, Progesterone / Q000032:analysis
D014408:Biomarkers, Tumor; D011980:Receptors, Progesterone; D019009:Proto-Oncogene Proteins c-kit