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Tarlov Cyst: A diagnostic of exclusion
Cyril Andrieux1, Pietro Poglia1, Pietro Laudato2
1CHUV, Service d'orthopédie et de traumatologie - CHUV, 1012 Lausanne, Switzerland.
Abstract:
Tarlov cysts were first described in 1938 as an incidental finding at autopsy. The cysts are usually diagnosed on MRI, which reveals the lesion arising from the sacral nerve root near the dorsal root ganglion. Symptomatic sacral perineural cysts are uncommon and it is recommended to consider Tarlov cyst as a diagnostic of exclusion. We report a case of a patient with voluminous bilateral L5 and S1 Tarlov cyst, and right hip osteonecrosis to increase the awareness in the orthopaedic community. A 57-year-old female, in good health, with chronic low back pain since 20 years, presented suddenly right buttock pain, right inguinal fold pain and low back pain for two months, with inability to walk and to sit down. X-ray of the lumbo-sacral spine revealed asymmetric discopathy L5-S1 and L3-L4. X-ray of the right hip did not reveal anything. We asked for an MRI of the spine and it revealed a voluminous fluid-filled cystic lesion, arising from the first sacral nerve root on both side and measuring 3,3cm in diameter. The MRI also show a part of the hip and incidentally we discovered an osteonecrosis Ficat 3 of the right femoral head. The patient was taken for a total hip arthroplasty, by anterior approach. Patient appreciated relief of pain immediately after the surgery. The current case show that even if we find a voluminous cyst we always have to eliminate other diagnosis (especially the frequent like osteonecrosis of the femoral head) and mostly in the case of unclear neurological perturbation.
Insights
Tarlov cysts, fluid-filled sacs on sacral nerve roots, can cause pain. This case highlights a large bilateral Tarlov cyst associated with hip osteonecrosis, emphasizing the need for differential diagnosis in complex pain presentations.
Area of Science:
- Neurology
- Orthopedics
- Radiology
Background:
- Tarlov cysts are typically incidental findings originating from sacral nerve roots.
- Symptomatic sacral perineural cysts are rare and often a diagnosis of exclusion.
- This case presents a large bilateral Tarlov cyst co-occurring with hip osteonecrosis.
Purpose of the Study:
- To report a rare case of symptomatic bilateral Tarlov cysts.
- To highlight the association of Tarlov cysts with hip osteonecrosis.
- To increase awareness among orthopedic specialists regarding this differential diagnosis.
Main Methods:
- Case report of a 57-year-old female with chronic low back pain.
- Diagnostic imaging including X-ray and MRI of the spine and hip.
- Surgical intervention with total hip arthroplasty.
Main Results:
- MRI revealed voluminous bilateral S1 Tarlov cysts (3.3cm) and incidentally Ficat 3 osteonecrosis of the right femoral head.
- The patient experienced immediate pain relief following hip arthroplasty.
- The co-occurrence of these conditions presented a diagnostic challenge.
Conclusions:
- Voluminous Tarlov cysts can be associated with other significant pathologies like femoral head osteonecrosis.
- It is crucial to exclude common diagnoses, such as osteonecrosis, in cases of unclear neurological symptoms.
- This case underscores the importance of comprehensive diagnostic evaluation in patients with complex pain syndromes.
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