Multinucleated tumor cells in clear cell renal cell carcinoma

Abstract

Objectives: Multinucleated tumor cells (MTCs) in clear cell renal cell carcinoma (ccRCC) are not well understood.

Methods: Our study included ccRCC cases in a single institution between 2010 and 2019. We classified MTC as MTC with degenerative atypia (MTCD), MTC with no anaplasia (MTCNA), and MTC with anaplasia (MTCA). Clinicopathologic characteristics and outcomes were compared between MTC groups.

Results: In all, 92 of 256 people (36%) with ccRCC had MTC. People with ccRCC with MTCD and those with ccRCC but no MTC had similar clinicopathologic characteristics and outcomes. Also, MTCNA and MTCA were associated with larger tumor size, advanced pathologic tumor stage, higher World Health Organization/International Society of Urologic Pathologists nuclear grade, and higher metastatic potential (P < .001 for each parameter). Overall, MTCA was associated with an increased rate of recurrence (P = .004), higher metastatic potential (P < .001), and shorter time to metastasis (P = .033), regardless of tumor stage. Univariate Cox regression revealed MTCNA as a significant predictor of metastasis at 5 years (hazard ratio [HR], 4.171; 95% CI, 1.934-8.998); moreover, MTCA was a significant predictor of recurrence (HR, 5.723; 95% CI, 2.495-13.124), metastasis (HR, 12.024; 5.966-24.232), and death (HR, 5.661; 95% CI, 2.688-11.924) at 5 years.

Conclusions: Although MTCD may not be relevant in tumor grading, MTCNA and MTCA are associated with adverse outcomes.

Keywords: clear cell renal cell carcinoma; multinucleation; tumor grading.