Multiple Discordant Histology After Nephrectomy: Descriptive Analysis and Outcomes

Area of Science:

• Urology
• Nephrology
• Oncology

Background:

• Renal tumors are common, but multiple ipsilateral lesions with different histological subtypes are rarely documented.
• This study addresses the infrequent occurrence of synchronous, histologically unique, primary renal neoplasms within the same kidney.

Purpose of the Study:

• To evaluate the institutional experience with synchronous, histologically unique, primary renal neoplasms within the same kidney.
• To analyze the characteristics and clinical course of patients with multiple, discordant renal histology.

Main Methods:

• Retrospective analysis of 2 institutional nephrectomy databases (2000-2013).
• Inclusion of 15 patients with multiple, discordant renal histology after partial or radical nephrectomy.
• Assessment of demographic data, immunohistochemical analysis, and clinical course.

Main Results:

• The most common discordant histology pairing was clear-cell renal-cell carcinoma (ccRCC) with chromophobe RCC (19%).
• Three patients (19%) had a single tumor with two distinct patterns, all involving ccRCC with papillary RCC.
• 20% of patients developed metastatic disease, with a median cancer-free survival of 2 months for those with metastasis.

Conclusions:

• Multiple, discordant renal pathology is a rare entity in nephrectomy patients.
• This study presents the largest cohort of synchronous renal tumors, highlighting ccRCC/chromophobe RCC as the most frequent combination.