Pilonidal cyst is a swelling that starts under the skin on the sacrum near the tailbone resulting in fistula formation. Although the exact causes of cyst formation has not yet been accurately determined, it is believed that this is due to an infection caused by hair follicle inflammation – folliculitis that progresses over time leading to a larger subcutaneous abscess.
Hydrocele is an accumulation of tissue fluid in the scrotum, between the testicular membranes, leading to the scrotum enlargement and discomfort. Hydrocele is commonly diagnosed in the new-born babies, however in children before they reach the age of one year, it usually resolves by itself, spontaneously. The cause of hydroceles in adults may be related to trauma, inflammation and infections.