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Uncommon synovial cysts in children
Johannes Roth1, Ianina Scheer, Stephan Kraft
1Pediatric Rheumatology, Charite-Universitaetsmedizin, Berlin, Germany. johannes.roth@charite.de
Insights
Uncommon synovial cysts, often presenting as soft tissue masses, are frequently linked to arthritis in children. Prompt diagnosis and arthritis treatment lead to cyst resolution, with ultrasonography being the preferred imaging method.
Area of Science:
- Pediatric Rheumatology
- Pediatric Radiology
- Pediatric Orthopedics
Background:
- Synovial cysts, commonly known as Baker's cysts, typically occur in adults.
- Atypical synovial cysts in children, presenting as soft tissue masses or pain, can be misdiagnosed as tumors.
- Understanding the presentation and course of these uncommon cysts in children is crucial for accurate diagnosis and management.
Purpose of the Study:
- To describe the underlying diseases, clinical presentations, and clinical courses of six children with atypical synovial cysts.
- To evaluate the role of imaging modalities, particularly ultrasound and MRI, in diagnosing these conditions.
- To determine the outcomes of synovial cysts based on the presence or absence of underlying arthritis.
Main Methods:
- Case series describing six pediatric patients with sudden onset paraarticular soft tissue masses or chronic pain.
- Initial diagnosis using ultrasonography for all patients.
- MRI utilized in three patients for further characterization.
- Underlying conditions, including juvenile idiopathic arthritis (JIA) and Lyme Arthritis, were investigated.
Main Results:
- Ultrasonography revealed well-demarcated, hypoechogenic lesions with no perfusion, extending into adjacent musculature from various joints (shoulder, elbow, hip, knee, ankle).
- A direct connection between the cysts and the joint was confirmed in all cases.
- Four children were diagnosed with JIA, one with Lyme Arthritis, and one with an unidentified underlying condition.
- Synovial cysts resolved rapidly with arthritis treatment in five patients; the cyst persisted in the non-arthritic patient.
Conclusions:
- Uncommon synovial cysts in children are often a complication of underlying arthritis.
- Ultrasonography is the primary imaging modality for diagnosis and follow-up of synovial cysts.
- MRI can supplement ultrasonography in complex or unusual cases.
- Treatment of the underlying arthritis is the primary therapeutic approach, with specific interventions for the cysts often unnecessary.
Unlabelled:
Popliteal synovial cysts (Baker's cysts) are a common occurrence in children and adults. Synovial cysts in other locations and/or with atypical extension are less common and may be confounded with tumors or other medical conditions. In this article we describe the underlying disease, clinical presentation and clinical course in six children with a sudden onset of paraarticular soft tissue masses or non-specific chronic pain. Ultrasound was the initial imaging method used in all cases; this was supplemented by MRI in three patients. Four children were diagnosed to be suffering from juvenile idiopathic arthritis (JIA), one child from Lyme Arthritis, whereas in one child no underlying disease was identified. Well-demarcated hypoechogenic lesions without signs of perfusion extending from the shoulder (two patients), elbow (one patient), hip (one patient), knee (1) or ankle (one patient) far into the adjacent musculature were detected on ultrasonography. A direct connection to the joint was demonstrated in all cases. All synovial cysts in the five arthritic patients resolved rapidly with medical treatment for arthritis, whereas the cyst persisted in the non-JIA patient.
Conclusion:
Uncommon synovial cysts occur in particular as a complication of arthritis. Ultrasonography is the initial and follow-up imaging method of choice, which can be supplemented by MRI in unusual cases. Apart from treatment for arthritis, no specific therapeutic interventions were required in the present cases.
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