Is A Surgery Needed For Unilocular Cyst In POD?

My ultrasound report says in different dates; July 19, 2013: A large thin walled unilocular cyst measruing 104x84x63 mm (287 cc) noted in POD. No internal echoes or solid component seen. Jan 27, 2014: Cyst measuring 78x46x79 mm (151 cc) in right parauterine region. No internal echoes or solid component seen. left ovary is normal in size measuring 29x19x28 mm (volume = 8.2 cc) with small follicles. April 06, 2014: A thin walled unilocular cyst measuring 83x49x31 mm (volume = 68 cc) is noted in right parauterine region and extending into the POD. July 21, 2014: Thin wall cyst measuring 83x55x87 mm (223 cc) in right paratuerine region. No internal seen. Left oveary is normal in size measuring 20x11x28 mm (2.3 cc) with small follicle. Please suggest..whether i go to Operate this or i have any alternative except operation.