Primary parenchymal squamous cell carcinoma of the kidney: A case report

Abstract

Background: Primary squamous cell carcinoma (SCC) of the renal parenchyma is extremely rare, with only nine cases reported.

Case summary: This study reports a 51-year-old man with primary SCC of the renal parenchyma. The patient was admitted with recurrent dull pain and discomfort in the right lumbar region, which had worsened over 2 weeks, accompanied by painful gross hematuria. SCC antigen (SCCA) levels were elevated, and imaging revealed a renal mass with associated calculi. The patient underwent laparoscopic unilateral nephrectomy and lymph node dissection. Postoperative pathology confirmed highly differentiated SCC with necrosis in the right renal parenchyma, with negative renal pelvis and ureter. The pathological stage was Pt3aN1M0. Four months after surgery, the tumor recurred with involvement of the liver, right psoas major muscle, and inferior vena cava. The patient refused chemotherapy and succumbed to the disease 6 months postoperatively due to disease progression.

Conclusion: We report a case of primary SCC of the renal parenchyma, a rare renal malignancy. The clinical symptoms, laboratory tests, and imaging findings are nonspecific, making accurate and timely diagnosis challenging. According to the literature, for patients with renal calculi accompanied by a renal mass, elevated serum SCCA levels, and magnetic resonance imaging showing cystic or cystic-solid masses within the kidney with pseudocapsules and heterogeneous mild enhancement, the possibility of this disease should be considered.

Keywords: Case report; Computed tomography; Renal calculi; Renal parenchyma; Renal tumor; Squamous cell carcinoma.

Figure 1

Medical image. A: Ultrasound examination showing a mass in the right kidney with hypoechoic areas and echogenic stones within, accompanied by posterior acoustic shadowing. Color doppler flow imaging shows blood flow signals within the mass; B: Computed tomography urography views show the mass and internal stones Coronal; C: Sagittal; D: The tumor shows slightly low signal intensity on T1 weight ed imaging; E: Magnetic resonance T2-weighted imaging shows a clearly defined right renal tumor with a low signal pseudocapsule (arrow). The internal signal is heterogeneous, with nodular short T2 signal stones and long T2 cystic necrosis. The solid tumor tissue shows isointense T2 signal; F: Diffusion-weighted imaging shows high signal intensity in the solid tumor tissue and low signal intensity in the cystic necrotic areas. Enlarged lymph nodes are visible in the retroperitoneum (arrow); G: Apparent diffusion coefficient map shows low signal intensity in the solid tumor components; H: Contrast-enhanced scan shows heterogeneous mild enhancement of the solid tumor components.

Figure 2

High-grade squamous cell carcinoma tissue within the renal parenchyma, with a significant inflammatory cell response in the stroma (Hematoxylin-eosin stains × 10).

Figure 3

Enhanced computed tomography scan four months post-surgery. A: The original surgical area shows a mass; B: The tumor invaded the psoas major muscle (arrow) and the right abdominal wall; C: The mass also invades the VI segment of the liver (asterisk) and the inferior vena cava (arrow).