Researchers at Fox Chase Cancer Center and Temple University Hospital have found that genetic testing may be the most effective way to distinguish between two types of kidney cancer, according to a recent study. The research focused on mucinous tubular and spindle cell carcinoma (MTSCC), a rare subtype of kidney cancer, and papillary renal cell carcinoma (PRCC), which is more common.
MTSCC is typically identified by tubules, spindle cells, and mucinous connective tissue, while PRCC is usually characterized by finger-like projections called papillae. However, the new study revealed that papillary formation was present in all five cases of MTSCC examined.
“Typically, papillary formation in mucinous tubular and spindle cell carcinoma is not a common finding. However, in this study we found papillary formation in all five cases of MTSCC,” said Wei, senior author and Associate Professor as well as Medical Director of the Clinical Genomics Laboratory at Fox Chase.
Wei explained that this finding challenges previous assumptions about using papillary formations as a marker for diagnosing PRCC. With these features now observed in MTSCC cases as well, diagnosis becomes more complicated when relying on sample methods such as fine needle aspiration. The overlap means molecular testing is needed for an accurate diagnosis between MTSCC and PRCC.
The research team included lead author Samir Amer, MD, PhD—a fourth-year resident and chief resident in the Department of Pathology at Temple University Hospital—along with others from both institutions. They compared five cases of MTSCC with papillary formation to 18 cases of PRCC. Chromosomal analysis was used to confirm diagnoses.
“We want to stress that molecular testing is very useful to distinguish MTSCC from PRCC on a small specimen, and an accurate diagnosis means a better, more effective treatment plan for the patient.”
Wei noted that further research will be necessary to determine whether all MTSCC tumors share similar clinical and molecular characteristics.
Fox Chase Cancer Center has been located in Philadelphia since its founding in 1904. The center’s current president is Dr. Robert Uzzo. In 2022, Fox Chase reported performing over 5,000 surgeries and admitting nearly 3,500 patients for treatment (https://www.foxchase.org/about-us/annual-report).
The study appeared in Human Pathology.
