Localized amyloidosis of the upper urinary tract: A case series of three patients managed with reconstructive surgery or surveillance

Objective: To evaluate the clinical presentation, diagnosis, treatment, and prognosis of primary localized amyloidosis of the upper urinary tract. Methods: Patients with primary localized amyloidosis of the upper urinary tract were identified by database inquiry, and their medical records were reviewed. Results: Primary localized amyloidosis was identified in the ureter in two patients and in the renal pelvis in one patient. Systemic disease and amyloidosis secondary to a medical condition were excluded. All three patients presented with gross painless hematuria, and two also reported flank pain. None endorsed irritative urinary symptoms. Initial evaluation consisted of renal ultrasonography or intravenous urogram, and subsequently additional imaging and ureteroscopies with biopsies were performed. Congo red staining of the biopsies displayed apple green birefringence under polarized light. One patient was treated with distal ureterectomy and Boari flap ureteroneocystostomy, whereas the other two were followed with surveillance imaging. None of the patients have developed progressive disease or recurrence of their symptoms during follow-up of 15 months, 6 years, and 8 years. Conclusions: Primary localized amyloidosis of the upper urinary tract is a rare condition that is of interest because the clinical presentation and radiographic and endoscopic appearance mimic malignancy. Many commonalities exist between upper urinary tract and bladder amyloidosis, but obstructive features, like flank pain and hydronephrosis, are unique to upper urinary tract lesions. In the absence of significant obstruction, early eradication of an upper urinary tract lesion may not be necessary. Rather, follow-up with serial imaging is sufficient to monitor for disease progression.