Journal of Cancer Research and Therapeutics

: 2010  |  Volume : 6  |  Issue : 4  |  Page : 537--539

Squamous cell carcinoma of the renal pelvis presenting as hydronephrosis

Ranjana Bandyopadhyay1, Saumitra Biswas2, Dipanwita Nag1, Asit Kumar Ghosh1,  
1 Department of Pathology, Medical College, Kolkata - 700 073, India
2 Department of Pathology, N R S Medical College, Kolkata - 700 014, India

Correspondence Address:
Ranjana Bandyopadhyay
1B/3, Uttarpara Housing Estate, 88 B, G T Road, P.O.- Bhadrakali, Hooghly - 712 232, West Bengal


Primary malignant tumors of the renal pelvis are relatively rare with squamous cell carcinoma (SCC) accounting for 0.7% to 7%. We present a case of a 58-year-old male with huge hydronephrosis on the left side where histology of the resected specimen showed features of SCC. There was no evidence of renal calculi or other predisposing factors. The case highlights the rarity of the tumor in the absence of calculi, as well as the importance of a careful study of a gross specimen and histologic sections in every case of hydronephrosis.

How to cite this article:
Bandyopadhyay R, Biswas S, Nag D, Ghosh AK. Squamous cell carcinoma of the renal pelvis presenting as hydronephrosis.J Can Res Ther 2010;6:537-539

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Bandyopadhyay R, Biswas S, Nag D, Ghosh AK. Squamous cell carcinoma of the renal pelvis presenting as hydronephrosis. J Can Res Ther [serial online] 2010 [cited 2022 May 26 ];6:537-539
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Squamous cell carcinoma (SCC) of the renal pelvis is a rare tumor. The incidence of this tumor is 1.4% of all renal malignancies. [1] Different etiological factors including renal calculi, infection, endogenous and exogenous chemicals, vitamin A deficiency, and hormonal imbalance have been implicated in its pathogenesis. But tumors have been reported even in the absence of these factors. [2] We report a case of SCC of the renal pelvis presenting as hydronephrosis without any renal calculi. The tumor was diagnosed only after resection of the specimen.

 Case Report

A male patient, weaver by occupation and aged 58 years, presented with complaints of heaviness and swelling of left upper abdomen for last 1 year. The swelling was gradual in onset and he had occasional burning sensation in urine. There was no history of fever or hematuria. He also experienced occasional pain in the left loin without any radiation and there was a history of generalized weakness for 3 months. Routine hematology, biochemical tests, and chest radiograph were normal. Urinalysis revealed microscopic hematuria. Ultrasonography (USG) of whole abdomen showed huge hydronephrosis of left kidney with floating echogenic patches inside the hydronephrotic sac suggestive of pyonephrosis. The left ureter was normal. The right kidney was normal in size, shape, and echotexture. Urinary bladder was empty. There was no ascites or lymphadenopathy. CT scan showed left gross hydrenephrosis with a markedly dilated cystic pelvicalyceal system filling the abdominal cavity [Figure 1]. There was no history of past radiation exposure or renal stones.{Figure 1}

On operation, a huge specimen of kidney measuring 30×20×15 cm was obtained. The whole mass was a distended sac-like structure without any grossly visible renal tissue. The cut surface showed multiple loculi with necrotic material within it. Some areas showed thickening of wall with an irregular inner surface [Figure 2]. Histology of the irregular areas in the hydronephrotic sac revealed features of moderately differentiated SCC [Figure 3]. The tumor invaded the muscle but did not penetrate it. There was no involvement of the retroperitoneal soft tissues. The entire tumor showed exclusive squamous differentiation. No transitional element was found within the tumor. The regional lymph nodes were not involved and there was no distant metastasis at presentation (Pathological stage T2N0M0).{Figure 2}{Figure 3}


Primary malignant tumors of the renal pelvis are relatively rare and constitute approximately 8% to 14% of all the renal malignancies. [1] Urothelial carcinoma occurs in more than 90% of such cases and SCC in only 0.7% to 7%. [3] Women are affected more frequently than men, predominantly in the age group of 50 to 70 years. [2] SCC of the renal pelvis tends to be sessile, ulcerated, and infiltrative at the time of diagnosis. The presence of necrotic material and keratin debris in the surface is a relatively constant feature.

The diagnosis of SCC of the renal pelvis is restricted to tumors showing extensive squamous differentiation. If a significant urothelial element including urothelial carcinoma in situ is found, the tumor should be classified as urothelial carcinoma with squamous differentiation. The histologic hallmarks of pearl formation, intercellular bridges, and keratotic cellular debris are those of squamous carcinoma at any site. With the exception of the verrucous variant, most of these carcinomas are moderately or poorly differentiated and more deeply invasive at the time of diagnosis than the majority of transitional cell carcinoma. [4]

SCC of the urothelial tract is thought to arise through a process of metaplasia of the urothelium. A large percentage of patients have squamous metaplasia of the adjacent urothelium. Various etiological features have been held responsible for squamous metaplasia and subsequent carcinoma. Of these, renal calculi and infection are the leading ones. Other factors implicated include exogenous and endogenous chemicals, vitamin A deficiency and hormonal imbalance, schistosomiasis, and smoking. [1] However cases have been reported in which no apparent etiological factor could be detected. [2] In our case also, no such etiological factor could be identified. In the absence of calculi or the significant mass effect of the tumor, the etiology of hydronephrosis was difficult to explain. As the hydronephrotic sac was filled with necrotic materials and as the tumor was mainly exophytic in nature, some sloughed tumor tissue might have obstructed the ureter and had caused hydronephrosis. Another possibility is the tumor has arisen in a chronically inflamed hydronephrotic sac. Hydronephrosis and even pyonephrosis with peritoneal abscess formation have been reported in upper urinary tract carcinomas. [5] Ng et al, have described hydronephrosis to be strongly related to the advanced pathologic stage, mostly with diseases extending beyond the kidney and those showing metastasis. [6] They have also noted that hydronephrosis is more common in renal tumors than the renal pelvic ones.

Surgery is the mainstay of therapy in SCC of renal pelvis and may result in cure in low stage patients. Systemic chemotherapy has only marginal benefit. The prognosis of SCC of the renal pelvis is very poor with a median survival of 3.5 months. Their generally poor prognosis can be attributed to the typically advanced stage at diagnosis, but stage for stage, prognosis is similar for squamous and usual urothelial carcinoma. [7] In the present case, the patient received three cycles of platinum-based chemotherapy. He attended the follow up clinic up to 6 months without any evidence of metastasis, after which he was lost to follow up.

To conclude, SCC of the renal pelvis may present as hydronephrosis and a careful search for any abnormal area in the wall should be attempted especially in the presence of necrotic materials in the cyst. A diagnosis of malignancy should be considered in cases of inflammatory pathology involving the renal pelvis, who has no known risk factor such as calculi or diabetes mellitus. [2] Careful history taking may give some clue for the presence of risk factors but SCC of the renal pelvis may occur in the absence of any of the predisposing conditions. Interestingly in the present case the disease was confined to the organs with no local spread or evidence of metastasis.


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