Tumors Of The Kidney Benign Tumors :They rarely cause clinical problems.Renal Papillary Adenoma,Renal Fibroma , Hamartoma, oncocytoma,angiolipoma.Malignant Tumors : On the contrary to benign tumors, malignant tumors are clinically of great importance
Pediatric Tumors Nephroblastoma (Wilm’s Tumor) It is seen primarily in infants and children. There is no sex predilection. The classical clinical presentation in form of an abdominal mass, hematuria and pain are rare. Other features include; hypertension, proteinuria and sometime tumor rupture.
Molecular genetic features The genetic loci predisposing to nephroblastoma are:WT1 located on 11p13.WT2 located on 11p15.5.Other chromosomal abnormalities include, 1, 7q, 12, & 16.
Morphologic features Grossly:Tumors are solitary, well circumscribed, rounded and of soft in consistency. The size is variable, with a median weight of 550gm. The cut section is predominantly solid and pale gray or tan and often exhibits areas of cystic change, necrosis, and hemorrhage.Multicentric foci are found in 7% of cases.
Microscopically:Three major components are identified1. Undifferentiated blastema.2. Mesenchymal (stromal) tissue.3. Epithelial tissue.Anaplastic features may be present focally or extensively.
Adult Tumors And Tumor-Like Conditions:Renal Cell Carcinoma(hypernephroma) Average age at diagnosis is 55-60 years. Rarely may occur during childhood. The M:F ratio is 2:1, Epidemiology, there are many risk factors;1. Tobacco is the most significant factor.2. Obesity, particularly in women.3. Hypertension.4. Unopposed estrogen therapy.5. Exposure to, asbestos, petroleum products, and heavy metals.
Conditions that may be complicated by renal cell carcinoma are the followings;1. von-Hippel-Lindau (VHL) disease also called(familial cerebello retinal angiomatosis), renal cell carcinoma occurs in more than 50% of individuals with this syndrome.2. Acquired cystic renal disease, about 50% of the patients on long-term dialysis develop renal cysts, 7% of cases are complicated by cancer.3. Adult form of polycystic kidney disease and multicystic nephroma.4. Lymphoma.
Clinical features Clinical features include the classical triad of (hematuria (earliest and most common symptom; usuallyintermittent), palpable mass and flank pain.other manifestations are weight loss, anemia, fever, and symptoms caused by metastatic deposits. Rarely paraneoplastic manifestations may occur like polycythemia, high ESR, hypercalcaemia , cushing syndrom......
Morphologic features Grossly, most renal cell carcinomas are well delineated and cortical in location. Usually the cut surface is solid golden/yellow in color. Areas of hemorrhage, necrosis, calcification, and cystic change are common findings.
Microscopically, tubular and glandular growth of tumor cells with large nuclei, and cytoplasm ranging from granular to clear.
Other microscopic type Papillary renal cell carcinoma, It comprises about 15% of all cases of renal cell carcinoma.Renal tumors arising in patients on chronic hemodialysis are of this type. Microscopically, complex papillary formations are seen, and psammoma bodies are numerous. Stroma is heavily infiltrated by neutrophils and foamy macrophages. As a group, papillary renal cell carcinoma has a better prognosis than conventional RCC
Tumors of Renal Pelvis and Ureters Transitional Cell Carcinoma;Most cases occur in adults. There is a history of analgesic abuse and/or coexistence of renal papillary necrosis in approximately 1/4 of cases. Cases have been seen following administration of thorotrast Grossly, the tumors are soft, grayish/reddish masses, often diffusely involving the entire renal pelvis and may extend to the ureters. Tumors of the ureters might be located anywhere along their length.