A unique case of transitional cell carcinoma of renal pelvis in a patient with Lynch syndrome

Lynch syndrome-associated transitional cell carcinoma of the upper urinary tract is uncommon. Lynch syndrome is a well-known inherited condition with particularly increased risk of colorectal cancers and a lesser extent other types of cancers. We present a rare case of urothelial cancer associated with Lynch syndrome from the time of its diagnosis to its multidisciplinary management to date. This case report outlines the unique characteristics of the case. The patient was positive for a mutation in the MLH1 gene, a known mutation of Lynch syndrome, which has a sparse association to Lynch syndrome-related urothelial carcinoma compared to other genes, e.g., MSH2. The patient's second-degree relative had confirmed Lynch syndrome with the same MLH1 genetic mutation and had colorectal cancer. The first-degree female relative of the patient with urothelial cancer had breast cancer, also not commonly associated with Lynch syndrome. The patient's age at the time of diagnosis of urothelial cancer was 46 years, which is at the lower end of the spectrum of the average age of Lynch syndrome associated with urothelial cancers. This paper also presents a review of the literature regarding upper urinary tract transitional cell carcinoma, its association with Lynch syndrome and various opinions on screening guidelines for urothelial cancer in relatives of a patient diagnosed with Lynch syndrome.