Torsion - most commonly, with dermoid cysts and fibromas, but may occur with any mobile tumour of any size. The underlying cause is often unclear. Torsion always produces severe lower abdominal pain, often originating in the iliac fossa and radiating to the flank - so called "reverse renal colic." Nausea and vomiting are common. There may be a history of similar episodes representing partial twisting and untwisting of the pedicle. The mass may be extremely tender. Untreated, the tumour soon becomes necrotic.
Spontaneous rupture - occurs rarely, usually from internal haemorrhage or intracystic pressure. Unless the cyst is small, rupture is painful and accompanied by vomiting and various degrees of shock. Severe peritoneal irritation and the development of intra-abdominal adhesions may follow from rupture of a mucinous cystadenoma. Dissemination of tumour results.
Last reviewed 01/2018