What is the management approach for an 18mm simple cyst?

Management of an 18mm Simple Cyst

Simple cysts of 18mm should be managed conservatively with patient counseling and reassurance, as they typically follow an indolent course without significant changes in size over time and have minimal risk of complications. 1

Diagnostic Considerations

• Simple cysts are benign lesions that can be reliably identified by their characteristic imaging features: thin wall, anechoic interior, acoustic enhancement, and absence of internal elements 1
• Ultrasound is the first-line diagnostic modality for characterizing simple cysts and should be used if symptoms develop 1
• Simple cysts have an extremely low risk of malignancy, with studies showing virtually no malignancies in simple cysts in premenopausal women and only a single malignancy among thousands of simple cysts in postmenopausal women 1

Management Algorithm for Simple Cysts

For Asymptomatic Simple Cysts (18mm)

• No follow-up is recommended for asymptomatic simple cysts regardless of size 1
• Routine imaging surveillance is not necessary as most cysts (>80%) do not change in size over time, while a minority decrease in size, and an even smaller portion grow modestly 1
• Patient counseling and reassurance are the cornerstones of management 1

For Symptomatic Simple Cysts (18mm)

• If symptoms occur (abdominal discomfort, pain, distension), ultrasound should be the first diagnostic modality used to assess the cyst size and look for complications 1
• Treatment options for symptomatic cysts include:
  • Percutaneous aspiration with sclerotherapy (simple aspiration alone has high recurrence rates of 20-80%) 2, 3
  • Surgical intervention (laparoscopic fenestration) for persistent symptoms 3, 4
• Success of treatment should be defined by symptom relief rather than volume reduction of the cyst 1

Special Considerations

• If the cyst has irregular walls, septations, calcifications, or daughter cysts, further evaluation with enhanced CT or MRI is warranted to differentiate from cystic neoplasms 3
• Complications of simple cysts are rare but may include infection, hemorrhage, rupture, or compression of adjacent structures 3, 5
• For hepatic cysts specifically, the European Association for the Study of the Liver (EASL) strongly recommends against routine follow-up for asymptomatic simple hepatic cysts (96% consensus) 1
• For ovarian simple cysts, the American College of Radiology notes that simple cysts up to 10cm have minimal risk of malignancy 1

Common Pitfalls to Avoid

• Unnecessary imaging follow-up of asymptomatic simple cysts leads to increased healthcare costs and patient anxiety without clinical benefit 1
• Simple aspiration without sclerotherapy has high recurrence rates and should be avoided if intervention is needed 2, 6
• Overtreatment of asymptomatic simple cysts should be avoided, as they rarely cause complications 1, 5
• Post-treatment imaging is not indicated unless symptoms persist, as treatment success is defined by symptom relief rather than volume reduction 1