A collision tumor of papillary renal cell carcinoma and oncocytoma: case report and literature review.
OBJECTIVE
The most common renal neoplasms include clear cell, chromophobe, and papillary renal cell carcinomas (PRCCs) and oncocytomas. While lesions containing hybrid features of different tumor types, such as hybrid oncocytic tumors, have been well documented in the literature, the finding of a collision tumor of two distinct tumor types- PRCC and oncocytoma-is extremely rare.


METHODS
We present a case of PRCC associated with an oncocytoma. Our discussion includes a review of the available literature on this rare type of collision tumor.


RESULTS
Prosection of a partial nephrectomy performed in a 78-year-old man for painless gross hematuria and nocturia revealed a 6.4 × 5 × 3.6-cm well-delineated orange to yellow-tan mass harboring a white-tan 1 × 0.9 × 0.9-cm mass. Histologic diagnosis of PRCC associated with an oncocytoma was rendered. By immunohistochemistry, focal CK7 expression was present in the oncocytoma, while strong diffuse positive CK7 expression was present in the PRCC component. Fluorescence in situ hybridization (FISH) revealed trisomy 17 in 39.3% of PRCC tumor nuclei but no significant chromosomal aberration in oncocytoma.


CONCLUSIONS
In view of this and previously reported cases, thorough sectioning and examination, especially in large oncocytomas, is recommended to exclude the presence of an associated malignancy. To our knowledge, trisomy 17 by FISH has not been previously reported in these extremely rare tumors.
From the Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN and.
Rajen
R
Goyal
Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA.
Anil V
AV
Parwani
From the Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN and.
Lan
L
Gellert
From the Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN and.
Omar
O
Hameed
From the Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN and giovanna.giannico@vanderbilt.edu.
Giovanna A
GA
Giannico
D018249:Adenoma, Oxyphilic / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D002886:Chromosomes, Human, Pair 17 / Q000235:genetics; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007680:Kidney Neoplasms / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D008297:Male; D009030:Mosaicism; D009378:Neoplasms, Multiple Primary / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D009392:Nephrectomy; D014314:Trisomy / Q000175:diagnosis / Q000235:genetics
Collision tumor; Oncocytoma; Papillary renal cell carcinoma