Renal tumors Dr. Abdelaty Shawky Dr. Gehan Mohamed

2. Papillary RCC * Clinical Features: Comprises about 10% to 15% of all RCCs. More likely to be bilateral or multiple than other RCCs Significantly better outcome than that of the clear cell type.

* Gross Pathology: Solitary, well-circumscribed cortical mass. Necrosis and hemorrhage are common. More likely to be bilateral or multifocal than other RCCs.

* Histopathology: Papillae and tubulopapillary structures with fibrovascular cores. Foamy histiocytes expanding the papillary cores and Psammoma bodies are characteristic.

3. Chromophobe RCC * Clinical Features: About 5% of RCCs Significantly better prognosis than clear cell RCC.

* Gross Pathology: Solitary, spherical, well-circumscribed mass. Homogeneous, tan or light-brown cut surface.

* Histopathology: The cells have finely reticulated pale cytoplasm with prominent cell membrane

4. Collecting duct carcinoma * Clinical Features: Rare, comprising about 0.1% of RCCs. Flank mass, pain, and hematuria. One third have metastasis at presentation.

* Gross Pathology: Medullary location. Light-gray, white cut surface with invasive borders. Necrosis, hemorrhage, and cystic changes may be present.

* Histopathology: Highly infiltrative border Tubular and tubulopapillary structures surrounded by Inflamed desmoplastic stroma. The cells show high-grade atypia.

Staging of RCC

Wilms tumor (nephroblastoma)

* Clinical Features: Common solid tumor of childhood; 90% found before the age of 6 years with peak incidence at the ages 2 to 5 years. Rarely found in adults or neonates. Patients usually present with an abdominal mass or abdominal tenderness; may present with hematuria, hypertension, or rarely peritoneal symptoms if spontaneous rupture has occurred Treatment includes surgical resection, chemotherapy and radiation

* Gross Pathology: Typically single, well-circumscribed mass with lobulated appearance. The cut surface is variegated, bulging, pale- gray to tan-pink typically with extensive hemorrhage and necrosis; cyst formation may be seen

* Histopathology: Classically shows triphasic pattern consisting of blastemal, stromal, and epithelial components Blastemal component is arranged in diffuse sheets or thin cords or as nodular aggregates; Blastema consists of small, round cells with hyperchromatic nuclei showing coarse chromatin and scant cytoplasm

Wilms tumor

Wilms tumor (nephroblastoma)

References: Robbins and Cotran’s: Pathologic Basis of Disease. Seventh edition.