Question: Our oncologist documented a "renal mass," and I-m not sure how to code correctly for it. Is it the same thing as a neoplasm? Oregon Subscriber Answer: Don't code for a renal mass the same way you would code for a neoplasm -- they are definitely not the same thing. More information: A mass -- in this case, a mass in the kidney -- can mean a lot of things. These range from malignant or benign processes to abscesses, cysts or even a normal but hypertrophied portion of the kidney. Bottom line: You should certainly never assume that a mass is a neoplasm. What to do next: If you-re unable to clarify the diagnosis with your physician, the most appropriate diagnosis choice will be 593.9 (Unspecified disorder of kidney and ureter). If this were a neoplasm, you would report the diagnosis as 239.5 (Neoplasms of unspecified nature; other genitourinary organs).