Amyloidosis of the renal pelvis: a harbinger of mammary carcinoma?

[LOCALIZED AMYLOIDOSIS OF THE RENAL SINUS: A CASE REPORT]

An 80-year-old man was accidentally diagnosed with a left renal pelvic tumor by computed tomography (CT), and visited our hospital. A tumorous lesion with an inhomogeneous contrast effect occupying the left renal pelvis was confirmed by the contrast-enhanced CT scan, and enlargement of multiple lymph nodes around the aorta and inferior vena cava was recognized. Urine cytology of the left renal pelvis was pseudo-positive. In the preoperative diagnosis of left renal pelvic carcinoma cT3N2M0, left nephroureterectomy and lymph node dissection were performed. Pathological findings revealed an amyloid tumor confined to the renal sinus and diagnosed as localized amyloidosis.

Primary localized amyloidoma of the renal pelvis: A case report and literature review

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.