Abstract. Primary localized amyloidomas of the renal pelvis are challenging to diagnose, due to non-specific imaging results and the unusual location. The present study reports a rare case of primary localized amyloidoma of the renal pelvis and aims to illustrate the challenges in pre-operatively discriminating between this disease and transitional cell carcinomas. The present study identified that the mass was situated in the left renal pelvis using ultrasonography. A nephroureterectomy was performed following careful preparation. Finally, histopathological studies revealed that the tumor consisted of massive diffuse deposits of amyloid and microscopic amorphous eosinophilic material, which stained positively for Congo red, demonstrating potassium permanganate digestion. Consequently, a diagnosis of amyloid light chain-type amyloidoma was determined. Systematic examinations were performed following the unexpected diagnosis, which eliminated the possibility of amyloid associated-type amyloidoma. In total, 4 months post-surgery, the patient remained tumor-free.
IntroductionLocalized amyloidoma is generally divided into two styles: AL-type and AA-type. AL-type occurs with an immunocyte dyscrasia while AA-type occurs with chronic infection, non-immunocyte neoplasia or inflammation. Localized amyloidoma occurs most often in the mediastinum or abdomen. Although amyloidomas may occur in almost all organ systems in the body; however, primary amyloidoma of the renal pelvis is rare. Using the keywords: 'renal pelvis', 'amyloidoma' and 'amyloid tumor' and search terms (renal pelvis) and (amyloidoma or amyloid tumor) in PubMed (National Center for Biotechnology Information, U.S. National Library of Medicine, Bethesda, MD, USA), a literature search was performed and only 26 cases of primary amyloidomas of the renal pelvis were identified (Table I) (1-23). Primary localized amyloidoma may present as hematuria and lumbago (14). A primary localized amyloidoma of the renal pelvis consists of amyloid deposits that may present as malignant tumors (15). The present study reports the rare case of a patient with amyloidoma that was confined to the renal pelvis, and the patient exhibited similar symptoms to those of upper urinary tract transitional cell carcinoma (TCC). In addition, 26 cases of patients with primary amyloidoma of the renal pelvis identified from the literature were also reviewed. Nephrectomy was the most selected treatment in the reported cases. The majority of patients achieved long time disease free survival and good prognosis. (7). The clinical and pathological features of the cases were discussed, in particular, the treatment methods and prognosis.
Case reportA 56-year-old man presented to the Department of Urology, Sun-Yat Sen University Cancer Center (Guangzhou, China) with left flank pain, symptoms of urinary irritation and intermittent gross hematuria. The patient had experienced the symptoms for 6 years; however, in the month prior to presentation, the
Primary localized amyloidoma of the renal pelvis:A case ...