CYSTIC DISEASE OF THE KIDNEY

There are several cystic diseases of the kidney, some of which produce renal failure by causing disturbance of renal structure. Importantly, some conditions are heritable.

Adult polycystic disease is inherited in an autosomal dominant trait, generally becoming clinically manifest in adult life. Increasingly, disease is detected in childhood, with family screening and ultrasound examination. Cysts develop and progressively enlarge over a number of years, but remain asymptomatic until the number and size of the cysts is so great that the patient becomes aware of abdominal masses. At about the same time, the replacement and compression of functioning renal parenchyma by the cysts leads to slowly progressive impairment of renal function, and patients develop chronic renal failure and hypertension. Patients with adult-type polycystic renal disease may also develop cysts in the liver, lung and pancreas. There is an association with berry aneurysms of the cerebral arteries which, with development of hypertension, predisposes to intracranial hemorrhage.

Infantile polycystic disease is uncommon and is encountered at birth. Children develop severe renal failure, with compression of the lungs due to massive enlargement of the kidneys. Simple renal cysts are the most common form of renal cystic disease and must be distinguished from the congenital types discussed above. They are widely held to be acquired abnormalities, incidence increasing with age. They contain clear, watery fluid and have a smooth lining. Simple cysts may be single or multiple and vary in size, generally being no larger than 5—6 cm. They have no

effect on renal function, but may rarely become infected or develop haemorrhage.

Acquired cystic disease is seen in kidneys left in situ while patients are treated by dialysis or transplantation for chronic renal failure. The kidney is converted into a mass of large cysts. Hemorrhage into cysts is common, leading to bloodstained contents.

Stages of individual work in classStudy and describe the macrospecimens

Malignant glomerulonephritis («large mottled kidney»). Pay attention to the size (texture, appearance) of the kidney, and correlation and colour of the cortical and medullar substances on incision. How can we explain the appearance of the kidney? Which peculiarities of blood circulation are present in the kidney in glomerulonephritis?

Acute glomerulonephritis. Determine the size and the character of the kidney surface; describe the state of the cortical and medullar substances. List renal and extrarenal signs of glomerulonephritis. Explain the etiology and pathogenesis of the disease.

Ascending pyelonephritis. Describe the appearance of the serous membrane of the ureter and the pelvis of the kidney: size, surface, texture of the kidney. Determine the kind of inflammation, name the etiological factors of pyelonephritis, the ways of infection invasion to the kidney, complications and outcomes of pyelonephritis.

Secondary nephrosclerosis. Describe the appearance and size of the organ, its texture, state of the surface, cortical and medullar substances on incision. List the processes resulting

in secondary nephrosclerosis. Name the forms of nephrosclerosis and their outcomes.

Polycystic kidney. Describe the size of the kidneys, their appearance (the surface on incision). Explain the etiology, pathogenesis, outcomes of the disease.