Fox Chase Cancer Center and Temple Researchers Highlight Need For Molecular Testing in Diagnosing Two Types of Kidney Cancer

Sam Wei
 Shuanzeng “Sam” Wei, MD, PhD, Associate Professor in the Department of Pathology and Medical Director of the Clinical Genomics Laboratory at Fox Chase Cancer Center

PHILADELPHIA (August 5, 2025) — Genetic testing may be the most effective way for researchers to distinguish between a rare form of kidney cancer and another that is more common, potentially preventing misdiagnoses, according to a recent study by researchers at Fox Chase Cancer Center and Temple University Hospital.

Mucinous tubular and spindle cell carcinoma (MTSCC) is a rare subtype of kidney cancer that is characterized, as its name states, of tubules, spindle cells, and mucinous connective tissue. Papillary renal cell carcinoma (PRCC), which is a more common type of kidney cancer, is typically identified by the presence of finger-like projections called papillae.

“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 Shuanzeng “Sam” Wei, MD, PhD, senior author and Associate Professor in theDepartment of Pathologyand Medical Director of the Clinical Genomics Laboratory at Fox Chase.

Wei said the finding is striking because papillary formations have previously been the marker for determining whether a tumor is diagnosed as PRCC. However, because papillary formations have now been found in MTSCC cases, diagnosis of these rare tumors is more complicated, especially when using sample methods like fine needle aspiration. These common features mean it is necessary for researchers to do molecular testing in order to make a definitive diagnosis of either MTSCC or PRCC.

In this study, Wei worked with lead author Samir Amer, MD, PhD, a fourth-year resident and chief resident in the Department of Pathology at Temple University Hospital. The research team, which included others at Fox Chase and Temple, compared five cases of MTSCC with papillary formation with 18 cases of PRCC. Chromosomal analysis was then performed to confirm the diagnosis. 

“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 said further research is needed to determine whether all MTSCC tumors have similar clinical and molecular findings.

The study, “Mucinous Tubular and Spindle Cell Carcinoma With Papillae: A Report of 5 Cases and Comparison With 18 Cases of Papillary Renal Cell Carcinoma,” was published in Human Pathology. # # #

Fox Chase Cancer Center (Fox Chase), which includes the Institute for Cancer Research and the American Oncologic Hospital and is a part of Temple Health, is one of the leading comprehensive cancer centers in the United States. Founded in 1904 in Philadelphia as one of the nation’s first cancer hospitals, Fox Chase was also among the first institutions to be designated a National Cancer Institute Comprehensive Cancer Center in 1974. Fox Chase is also one of just 10 members of the Alliance of Dedicated Cancer Centers. Fox Chase researchers have won the highest awards in their fields, including two Nobel Prizes. Fox Chase physicians are also routinely recognized in national rankings, and the Center’s nursing program has received the Magnet recognition for excellence six consecutive times. Today, Fox Chase conducts a broad array of nationally competitive basic, translational, and clinical research, with special programs in cancer prevention, detection, survivorship, and community outreach. It is the policy of Fox Chase Cancer Center that there shall be no exclusion from, or participation in, and no one denied the benefits of, the delivery of quality medical care on the basis of race, ethnicity, religion, sexual orientation, gender, gender identity/expression, disability, age, ancestry, color, national origin, physical ability, level of education, or source of payment.

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