Bladder tumors (urothelial carcinomas) are graded using a two-tier system into low-grade and high-grade types. However, some tumors may have mixed features with a large component of low-grade carcinoma and a minor component of high-grade tumor, causing difficulty in grading and therapeutic decision-making. What is the biologic behavior of such tumors and how does one treat them?
That’s the question Pranav Renavikar, MBBS, a surgical pathology fellow at the University of Nebraska Medical Center, is aiming to answer. The question is an important one—bladder tumors are among the most common tumors for men, with more than 80,000 patients diagnosed each year.
“Our project deals with looking at noninvasive urothelial carcinomas that have a mix of low- and high-grade features,” Dr. Renavikar said, “because a lot of times we’ll see most of the lesion is low-grade, but there will be some areas that show high-grade features (nuclear atypia, increased mitosis, more pleomorphism).”
“And obviously, for high-grade lesions there is a higher chance of that tumor recurring or invading or just progressing into something adverse. Whereas low-grade tumors don’t as much,” he said. “The therapy is different when we call something low-grade or high-grade. Low-grade lesions are usually resected by a procedure called trans-urethral resection of the bladder tumor. The high-grade lesions can be resected, but at the same time (patients) may get additional therapy, like chemotherapy or immunotherapy. So, the distinction is important.”
“Such lesions with mixed features and their progression, behavior, and long-term outcome are understudied,” Dr. Renavikar said. “We aim to characterize the immunohistochemical phenotype of these lesions and correlate with clinical follow-up. The data will be used to develop a risk prediction model.”
His study is made possible by the Department of Pathology, Microbiology and Immunology’s Research Grant Awards, created in 2024. The awards provide up to $10,000 in research funding to residents and fellows. The aim of this program is to advance the experience and mentorship in clinical and translational research.
Dr. Renavikar and Subodh M. Lele, MD, the surgical pathology fellowship director, have presented and published several studies in genitourinary pathology over the past four years.
“Studies such as these are quite time-consuming, as they involve going over large quantities of data, selection of blocks and additional investigative methods,” Dr. Lele said. “Our department is fortunate to have someone like Dr. Renavikar, who is exceptionally hardworking, diligent, and motivated in finding answers.”
Dr. Renavikar called the Research Grant Awards a great opportunity for young researchers.
“It’s a really amazing initiative by our leadership,” he said, “to give residents and fellows a boost as they learn to develop an investigator mindset in their research.”
Dr. Renavikar, who earned his medical degree in India, was a research scholar at the University of Iowa, where he was exposed to a lot of pathology and immunology. He then became a pathology resident at UNMC, completing that training in 2024. After his fellowship, he’ll join the UNMC faculty in the fall.
“Dr. Lele is my fellowship director and my mentor for this project. We will keep doing more projects as part of my faculty appointment,” he said. “My focus will be cardiac and thoracic pathology. There’s tremendous opportunity in those fields, too. I’m looking forward to it.”