Secondary involvement of the gastrointestinal tract by renal cell carcinoma.

Secondary involvement of the gastrointestinal (GI) tract by renal cell carcinoma is rare. We undertook a retrospective review of our institution's pathology records from January 2006 to July 2017 and identified eight cases of GI tract involvement by renal cell carcinoma. Sites of involvement included stomach, duodenum, jejunum, ileum, and cecum. Pertinent clinical information was obtained from electronic medical records. The interval from primary resection to identification of GI involvement was often prolonged, averaging 6 years, and mimicked primary GI tract malignancies, with presentations including GI bleeding, abdominal pain, and obstruction. One case presented asymptomatically on follow-up imaging. Histologic patterns of involvement varied from classic clear cell to purely sarcomatoid or complex unclassifiable morphology. Two patients with tumors exhibiting sarcomatoid morphology died within 2 years of primary resection and <1 year of GI involvement. The remaining patients survived a mean of 9 years (range, 5 to 22 years) at their last available follow-up.