A squamous cell carcinoma of the renal pelvis with special reference to pathogenesis

Oh, Dal Bong; Han, Chae Hee; Lee, Jin Moo; Wang, Chong Soon; Park, Chan Il; Bae, Bo Suk; Lee, Yong Woo

Abstract

A case of squamous cell carcinoma arising in the renal pelvis is reported in view of its rarity. The patient was 57 year old male who bad complained of epigastric and left flank pain with weight loss of 8 kg during about 6 months Polyphagia, polyuria and urinary frequency were noted since 2 years ago, but there was no hematuria. At the time of admission, intra-abdominal organs or lymphnodes were not palpated but severe costovertebral angle tenderness was present at the left flank. KUB and IVP showed a large radioopaque density in the left kidney area suggesting staghorn stone. Nephrectomy of the left kidney including resection of the proximal 3 cm of the ureter was performed. The removed left kidney, which bad smooth surface and relatively intact capsule but focal thickening, was 150gm in weight and measured as 12 X 7.5 X 5.5 cm. The kidney surface was adhered to the surrounding fat depots. On cut section, the pelvis and major calyces were distended, measuring 5.5 X 3.5 X 2.5cm and filled with a large staghorn stone surrounded by well circumscribed, white, dense and hard zone without capsule, measuring 3 cm in thickness. The cortico-medullary junction was entirely obliterated. The ureter was slightly dilated up to 1 cm in diameter and inflamed. Histopathologically, the kidney tubules were filled with colloidal material and the interstitial tissue showed marked infiltration of small round cells, plasma cells and histiocytes especially at the cortex. The renal pelvis was not lined by transitional epithelium but squamous epithelium with distinct inter-cellular bridges. There were fairly large number of keratin pearls, massive necrosis and diffuse infiltration of well differentiated squamous cell carcinoma into the medulla forming nests or cords with desmoplasia. The ureter revealed only mild inflammatory cell infiltration and marked edema.