Primary localized amyloidosis of the bladder: a case report with review of the literature and criteria for classification of amyloidosis

Tumour-like primary localized amyloidosis of the urinary bladder is a rare condition. Only 43 cases have been reported in the literature and, to our knowledge, there are no reports from Australia. The clinical presentation and cystoscopic appearances mimic malignancy. Diagnosis depends on the classical histopathological appearances of the lesion seen on biopsy. We report such a case with some unusual features. A 35 yr old man presented with recurrent painless hematuria. Cystoscopic examination revealed a large ulcerative lesion not unlike carcinoma. IVP and retrograde pyelogram revealed no abnormalities. Hematological and biochemical investigations were normal with no evidence of either systemic amyloidosis or plasma cell dyscrasia. However, immunostaining of the resealed bladder lesion by both the PAP and FITC fluorescence techniques demonstrated monoclonality of the plasma cell infiltrate around tumour-like amyloid deposits, indicating localized amyloidosis of the AL type, and a possible variant of a covert immunocyte-derived dyscrasia. The significance of these findings and its relevance to the recently proposed classification of amyloidosis will be presented.