Indian Journal of Urology
: 2000  |  Volume : 17  |  Issue : 1  |  Page : 55--57

Mucinous (intestinal) metaplasia of renal pelvic epithelium due to PUJ obstruction

Dilip Kumar Pal, Sikha Das 
 Departments of Urology and Pathology, North Bengal Medical College, Darjeeling, India

Correspondence Address:
Dilip Kumar Pal
«DQ»Ranikuthi«DQ», 28/1, Rudra Main Road, P.O.: Bansberia, Dist.: Hooghly, West Bengal - 712 502

How to cite this article:
Pal DK, Das S. Mucinous (intestinal) metaplasia of renal pelvic epithelium due to PUJ obstruction.Indian J Urol 2000;17:55-57

How to cite this URL:
Pal DK, Das S. Mucinous (intestinal) metaplasia of renal pelvic epithelium due to PUJ obstruction. Indian J Urol [serial online] 2000 [cited 2022 Jul 5 ];17:55-57
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 Case Report

A 50-year-old male, presented with a history of slow­growing huge lump in left flank for last 6 months. On examination it was found to be left kidney lump with smooth surface and firm consistency.

He had normal haemogram, urinalysis, urine culture and renal biochemical parameters. USG suggested hugely en­larged left kidney with mixed echogenecity. IVU demon­strated a non-excretion of contrast on left side with a large soft-tissue shadow in the renal region. Contrast C.T. scan showed a markedly enlarged left kidney (16 x 12 cm) with papery thin parenchyma and grossly dilated pelvicalycial system without any contrast excretion [Figure 1]. Left-sided RGP demonstrated hydronephrosis with PUJ obstruction [Figure 2].

Left-sided nephrectomy was undertaken by standard flank incision. On opening, the kidney and pelvis was dis­tended with thick copious viscid mucinous material. Cut surface showed gross hydronephrotic changes with dilated pelvis (8.4 cm) which had a thick smooth wall with granu­lar deposits. The renal cortex was secondarily thinned to a fibrous rim. Other significant finding was severe ure­teropelvic stenosis. No calculi was present in either the kidneys or in the ureter.

Histopathology suggested features of chronic pyelone­phritis with mucin-secreting cell lining of epithelium with minimum complexity. The nuclei of epithelial cell was uniform with no invasion [Figure 3].


Mucinous (intestinal) metaplasia of the urothelium is a rare condition with scant literature in which significant portion of urothelium is completely replaced by colonic type mucosa as a result of long-standing irritation. [1],[2] Rarely it is seen in the urinary bladder mucosa due to long-stand­ing indwelling catheter, calculus, chronic infection, blad­der outlet obstruction, stricture urethra, prostatitis, cystocele, [1] bladder extrophy, neurogenic bladder, [2] etc. Only few cases of mucinous metaplasia of renal pelvic epithelium is reported as a result of long-standing irrita­tion due to renal calculus, [1] but till now no case is reported due to PUJ obstruction.

Histologically the disease is similar with well-differen­tiated mucinous adenocarcinoma but differentiating fea­tures are infiltrative architectural pattern, dissecting mucin pool, muscle invasion, greater degree of anaplasia and mitotic figures. [2],[3] Though these lesions may gradually progress to adenocarcinomatous changes in urinary blad­der, [2] but in kidney there is no evidence to suggest this metaplasia is premalignant. [3]


1Bullock PS, Thoni DE, Murphy WM. The significance of colonic mucosa (intestinal metaplasia) involving the urinary tract. Cancer 1987; 59: 2086-2090.
2Jacobs LB, Brooks JD, Epstein JI. Differentiation of colonic meta­plasia from adenocarcinoma of urinary bladder. Hum Pathol 1997; 28: 1152-1157.
3Spires SE. Banks FR, Cibull ML et al. Adenocarcinoma of renal pelvis. Arch Path Lab Med 1993: 117: 1156-1160.