Dermatofibroma are common benign skin tumours that cause lumps in the skin and frequently cause concern upon discovery. The causes of dermatofibroma may include a reaction to trauma such as insect bites but the precise cause is often unclear.
Causes. It's not clear what causes simple kidney cysts. One theory suggests that kidney cysts develop when the surface layer of the kidney weakens and forms a pouch (diverticulum). The pouch then fills with fluid, detaches and develops into a cyst. 1  Symptoms. 2  Risk factors.
Furthermore, Kidney Cyst can result from many other health conditions. Polycystic kidney disease (PKD),multicystic dysplastic kidneys, nephronophthisis and medullary cystic disorder are commonly conditions which can cause formation of many renal cysts. The above are the major causes of complex renal cyst.Control of those problems can help manage the cysts better.