Urinary bladder xanthoma: a multi‐institutional series of 17 cases

AIMS: To present a series of urinary bladder xanthomas and characterize their clinical features and associated pathology. METHODS AND RESULTS: We retrieved the clinicopathological data of bladder xanthomas, with and without associated urothelial neoplasms. We identified six isolated bladder xanthomas and 11 arising within or adjacent to urothelial neoplasms. The biopsies showed lamina propria aggregates of foamy histiocytes, without an accompanying inflammation. Patients presented either incidentally or with microscopic haematuria or irritative symptoms. Patients with isolated xanthomas had a mean age of 65.3 years (range: 54-75 years) and an equal male to female ratio. Four of five patients with isolated xanthomas with available serum results had an abnormal lipid profile. Eleven patients had xanthomas associated with urothelial neoplasms [papilloma n = 4, papillary urothelial neoplasm of low malignant potential (PUNLMP) n = 2 and low-grade urothelial carcinoma n = 5]. Mean patient age was 62.5 years (range: 51-69 years) and all were male. Of the six patients with metabolic abnormalities, five had hypercholesterolaemia and one had a history of diabetes mellitus. CONCLUSION: Bladder xanthomas are rare lesions found in older patients who present either non-specifically or with microscopic haematuria or irritative symptoms. These lesions are often associated with underlying lipid abnormalities. A biopsy is recommended for an accurate diagnosis and to exclude neoplasia.