Primary Intraparenchymal Squamous Cell Carcinoma of the Kidney: A Rare and Unique Entity

Primary squamous cell carcinoma (SCC) of the renal parenchyma is a very unusual entity which needs to be differentiated from primary SCC of renal pelvis, SCC from another primary site, and urothelial carcinoma with extensive squamous differentiation. We are most probably describing the second case of primary SCC of the renal parenchyma in a 51-year-old male who presented with heaviness of right upper abdomen with intermittent pain in right flank. Contrast-enhanced computed tomography (CECT) revealed a mass in the right lower pole of the kidney and histopathology following nephrectomy displayed the features of well-differentiated squamous cell carcinoma without urothelial involvement. 1. Introduction Primary squamous cell carcinoma (SCC) of the renal pelvis is a rare but relatively known entity representing only about 0.5 to 15% of all the urothelial cancers. It is often unsuspected clinically due to its rarity and inconclusive clinical and radiological features, and hence patients present at advanced stages resulting in poor prognosis [1]. However, extensive review of the literature reveals only a single case of primary SCC of renal parenchyma reported till date [2]. We probably report the second case of primary SCC of renal parenchyma in a 51-year-old man presenting with nonspecific clinical complaints. 2. Case Report A 51-year-old male presented with heaviness of right upper abdomen for last 8 months and dull and intermittent pain in the right flank, off and on for last five months. There was no history of weight loss and hematuria during this period. History of fever with associated urinary complaints was also conspicuously absent. He was a nonsmoker and nonhypertensive. The clinical examination revealed mild pallor and mild tenderness in the right flank. There was no palpable lymph node. On routine hematological investigation, his hemoglobin level was 10.2？g/dL and RBCs displayed normocytic normochromic features on peripheral blood film examination. The erythrocyte sedimentation rate (ESR) was 40？mm after the 1st hour. Serum urea and creatinine values were within normal limits. Urine analysis revealed mild pyuria which was sterile on culture. Urine dip-stick test was negative for blood and urinary RBC count was within normal limit. However, mild proteinuria was detected. A solitary heterogeneously enhancing relatively well-delineated mass situated in the lower pole of right kidney was detected on contrast-enhanced computed tomography (CECT) scan without any noticeable infiltration of adjacent organs (Figure 1(a)). Retroperitoneal lymph nodes did not