Oncocytomas Tend to Grow Slowly Over Time
Growth does not seem to indicate malignancy; active surveillance seems safe
THURSDAY, Feb. 18, 2016 (HealthDay News) -- The majority of oncocytic renal neoplasms will grow with time, according to a study published in the March issue of The Journal of Urology.
Patrick O. Richard, M.D., from the Princess Margaret Cancer Center in Toronto, and colleagues conducted a single center, retrospective study of patients diagnosed with lesions suggestive of oncocytoma or chromophobe renal cell carcinoma between 2003 and 2014. A mixed effect linear model was used to estimate growth rates.
The researchers found that 98 percent of the 95 lesions (81 oncocytoma, 14 chromophobe renal cell carcinoma) included in the analysis were diagnosed on biopsy. During a median follow-up of 34 and 25 months, respectively, the annual growth rate was 0.14 cm for oncocytoma and 0.38 cm for chromophobe renal cell carcinoma. There was a significant correlation for baseline lesion size with growth (P < 0.001). Growth was detected in 74 percent of oncocytomas and 67 percent of chromophobe renal cell carcinomas followed up to the three-year mark. Of these, eight patients underwent surgery (six in the chromophobe renal cell carcinoma group). In all patients the initial diagnosis was confirmed. Five patients died, all of nonrenal-related causes.
"Our experience indicates that oncocytomas and to some extent chromophobe renal cell carcinoma can initially be safely observed with regular imaging," the authors write. "Patients should be reassured that growth is not necessarily a sign of malignancy as most lesions will grow slowly with time."
One author disclosed financial ties to Omnyx Digital Pathology.