Papillary renal cell carcinoma revisited: a comprehensive histomorphologic study with outcome correlations.
Papillary renal cell carcinoma (P-RCC) is the second most common type of malignant renal epithelial tumor and can be subclassified into type 1, which demonstrates simple cuboidal low-grade epithelium and type 2, which demonstrates pseudostratified high-grade epithelium with abundant eosinophilic cytoplasm. Despite this clinically useful subclassification, P-RCCs exhibit considerable histomorphologic diversity, with many cases having features differing from classically described type 1 and type 2 tumors. To our knowledge, there has been no recent study that has methodically evaluated the histomorphologic features of a series of P-RCCs. To address this, we evaluated a cohort of P-RCCs diagnosed between 1997 and 2004 with long-term clinical follow-up data (n = 56). Histomorphologic features previously described in the spectrum of type 1 and type 2 P-RCCs were recorded for each tumor, including nuclear grade, complete tumor capsule, and cytoplasmic eosinophilia as well as several other features. The current TNM staging (American Joint Committee on Cancer, seventh edition) was assigned to all cases. Histomorphologic features were diverse, demonstrating classic type 1 P-RCC and classic type 2 P-RCC morphology and several tumors with nonclassic features. Four patients in this cohort had distant metastasis. The primary tumor was equally divided between type 1 (2 cases) and type 2 (2 cases) morphology in the cases with metastasis. All P-RCC cases with metastases demonstrated presence of high nuclear grade and high tumor stage in the primary tumor. Cluster analysis using staging parameters and histomorphologic features divided tumors into 2 primary clusters. All primary tumors associated with metastasis were in the same cluster.
Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
Joshua I
JI
Warrick
School of Public Health, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
Alex
A
Tsodikov
Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Michigan Center for Translational Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
Lakshmi P
LP
Kunju
Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; School of Public Health, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Urology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Howard Hughes Medical Institute, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
Arul M
AM
Chinnaiyan
Department of Urology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
Ganesh S
GS
Palapattu
Department of Urology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
Todd M
TM
Morgan
Division of Hematology and Oncology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
Ajjai
A
Alva
Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Michigan Center for Translational Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Urology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
Scott
S
Tomlins
Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
Angela
A
Wu
Department of Urology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
Jeffrey S
JS
Montgomery
Department of Urology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
Khaled S
KS
Hafez
Department of Urology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
J Stuart
JS
Wolf
Department of Urology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
Alon Z
AZ
Weizer
Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Michigan Center for Translational Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Urology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA. Electronic address: mrohit@med.umich.edu.
Rohit
R
Mehra
D000328:Adult; D002291:Carcinoma, Papillary / Q000145:classification / Q000473:pathology*; D002292:Carcinoma, Renal Cell / Q000145:classification / Q000473:pathology*; D016000:Cluster Analysis; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000145:classification / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging
Nuclear grade; Papillary renal cell carcinoma; Tumor stage