Kidney Pathology Lectures PDF

PATHOLOGY LECTURES KIDNEY Target students: PATH 302- URS 301 BY Prof. Ragaa Amin Fawzy.  DSL DSL: [Pyelonephritis- Hydronephrosis] Normal Anatomy of the Kidney  Urinary system The nephron is the microscopic structural and functional un...

PATHOLOGY LECTURES KIDNEY Target students: PATH 302- URS 301 BY Prof. Ragaa Amin Fawzy.  DSL DSL: [Pyelonephritis- Hydronephrosis] Normal Anatomy of the Kidney  Urinary system The nephron is the microscopic structural and functional unit of the kidney. It is composed of a renal corpuscle and a renal tubule. The renal corpuscle consists of a tuft of capillaries called a glomerulus inside Bowman's capsule. The renal tubule extends from the capsule  Urinary system The glomerulus (plural glomeruli), is a network capillaries known as a tuft, located inside the Bowman's capsule. The tuft is supported by the mesangium (the space between the blood vessels made up of intraglomerular mesangial cells and matrix) Corpuscle/Glomeruli  Nephritic syndrome It is a name given to a collection of different signs and symptoms that occurs as a result of inflammation in the kidney. A syndrome is a set of medical signs and symptoms which are correlated with. each other and often associated with a particular disease or disorder 373102606_c52475a929_m  Acute diffuse proliferative glomerulonephritis Also called post streptococcal or acute glomerulonephritis It follows the infection of the upper respiratory tract by nephritogenic strains of group A beta hemolytic streptococci Deposition of immune complexes from antibodies against organisms occur in subepithelium of glomeruli it cause acute inflammatory response.  Acute infl. induce enodthelial cell proliferation endothelial cell proliferation cause narrowing of capillary lumen. This lead into decrease amount of blood in capillary lumen so decrease glomerular filteration rate. So diminished uriary out put..(oliguria). Kidney will d eal with this as ischemia so release renin /angiotensin with consequent salt and water retention……so odema occurs.  Nephritic syndrome Characters: - Hematuria - Mild to moderate proteinuria - Oliguria: passing less urine than normal - Uremia: elevated blood urea and creatinine - Azotemia: elevated nitrogen-rich waste compound in the blood - Edema: Face or leg - Hypertension  Clinical and Laboratory Findings Fever,malaise,loin pain. Oedema of face with buffiness of eyelids (Nephritic oedema). Nephritic Syndrome (Hematuria,Oliguria and Hypertension,Nephritic oedema). Serum shows Elevated ASO titre. Low complement level ,and Mild increase in urea. Urine shows oliguria,smoky,RBCs,Red cell casts and mild proteinuria (50 y - Sex: male :female 2:1 - smoking - Cadmium, benzene and asbestos exposure - Obesity and chronic dialysis - Genetic: von Hipple –Lindau syndrome  Renal cell carcinoma Gross Picture: - Well circumscribed solid mass centered on cortex. - Separated from surrounding by pseudocapsule - Often extend into renal pelvis & renal vein - Yellow color with hemorrhage, necrosis and cyst formation give this malignant tumor variegated golden yellow cut section. Renal cell carcinoma  Renal cell carcinoma Microscopic picture:3 main variants 1- Clear cell type: most common 80% malignant cells arranged in solid masses, cords or tubules with scanty stroma. The cells are usually large with clear cytoplasm. 2-Chromophobe cell type: cells are large in size with granular cytoplasm and distinct cell borders. - The stroma of both types 1&2 is scanty and very vascular with areas of hemorrhage and necrosis. 3-Papillary renal cell carcinoma:cells arranged In cysts with papillary formations  Renal cell carcinoma Clear cell Clear cell RCC Chromophobe RCC Compressed renal tissue(pseudocapsule  Clear cell renal cell carcinoma : Common variant80% Tumour cells are clear/granular , round or polygonal- explains the reason why they are sometime called clear cell carcinoma of the kidney Cells contain abundant glycogen and lipids - this explains why clear cytoplasm? as lipid dissolved during tissue processing Growth pattern - papillary , solid , glandular and trabecular - a mixture of all or one type of growth pattern predominant The vascular stroma is scanty and often fragile giving rise to many haemorrhagic areas  Papillary renal cell carcinoma 10-15% Sporadic and familial Branching papillae Single layer of cells Large nuclei Small amount of cytoplasm Different genetic factors. Tumor usually multifocal, bilateral, early diagnosed  Chromophobe renal cell carcinoma 5% Cells belongs to cortical collecting ducts Large cells. Granular eosinophilic cytoplasm(less clear). Perinuclaer halo. Prominent cell membranes. Compact growth pattern. Different genetic factors. Better prognosis.  Spread: Local spread : to rest of renal tissue , early invasion of renal pelvis, late invasion of capsule and perirenal fat. Lymphatic spread: lumber lymph nodes. Blood spread :early due to invasion of renal vein(after invasion of renal pelvis). Sites of blood metatasis : lungs ( over 50%) , bones (33%) ,, liver and brain as well as to the contralateral kidney. Left sided varicocele.(if it is left side RCC)why? Tumour has tendency to metastasise widely before giving rise to any local symptoms or signs How left renal cell ca lead to left side varicocele  Renal cell carcinoma Spread: Local, early blood spread and lymphatic Clinical presentation: - 1 Symptoms due to local spread - Painless hematuria - Loin mass. - costovertebral pain(late after infilterate capsule) - 2 Symptoms due Paraneoplastic Syndrome :Hypercalcemia, hypertension, polycythemia, Cushing syndrome and other hormonal manifestations due to paraneoplastic syndrome - 3 Symptoms due to distant metastases:bone fracture,cough ,convulsion,left varicocele.  Nephroblastoma Wilms tumor Definition: It is a malignant embryonal tumor occurs primarily in young children. - 50% before 3 years 40% between 3-10 years 90% before 10 years -It originates from nephrogenic blastema : cells which imitates the histology of developing kidney. -Rapidly growing.Early infilterate capsule Gross picture: marked enlarged kidney by huge mass. Outer surface is infilterating irregular Homogenous , grey and fleshy Cut section.  Nephroblastoma Wilms tumor Microscopic picture: 3 components - The blastema is extremely cellular area and consist of small, round primitive (undifferentiated) cells with scanty cytoplasm. - The mesenchymal elements consist of spindle fibroblasts, smooth muscle, skeletal muscle, cartilage or myxomatous tissue. - The epithelial component of malignant epithelial cells shows abortive (premature) tubules or glomeruli. IHC: blastema: WT1- desmin. Epithelium: keratin- EMA. Mesenchymal elements: according to type.  Nephroblastoma Wilms tumor Wilms tumor gross Wilms tumor microscopic  Spread: Local spread : rapid destroy rest of renal tissue, late invasion of pelvis, early invasion of capsule and perirenal fat and tissues. Direct spread to surrounding intestine,adrenal gland Lymphatic spread: lumber lymph nodes 15%. Blood spread : lungs, liver and brain.  Clinical picture Patient:child present with large abdominal mass whic may cross the midline common symptoms - hematuria and pain in the abdomen (local spread to renal tissue&capsule) Intestinal obstruction(local spread to intestine) may present with pulmonary metastasis May present with Hypertension(paraneopl.S)