Growth velocity of fetal sacrococcygeal teratoma as predictor of perinatal morbidity and mortality: multicenter study.

OBJECTIVE: To identify prenatal predictors of poor perinatal outcome in fetuses with isolated sacrococcygeal teratoma (SCT). METHODS: This was a retrospective study of fetuses with isolated (non-syndromic) SCT managed at one of five pediatric surgery and/or fetal medicine centers between January 2007 and December 2017. The primary outcome was the occurrence of poor perinatal outcome, defined as prenatal death (including termination), or neonatal death or severe compromise (hemorrhagic shock). Data regarding prenatal diagnosis (sonographic features both at referral and at the last ultrasound examination before pregnancy outcome, assessment of SCT growth velocity), perinatal complications and outcome, and neonatal course were analyzed to determine prenatal SCT characteristics associated with adverse perinatal outcome. RESULTS: Fifty-five fetuses were included, diagnosed with isolated SCT at a median gestational age of 22 (interquartile range, 18-23) weeks. There was a poor perinatal outcome in 31% (n = 17) of these cases, including intrauterine fetal demise (4%, n = 2), pregnancy termination (13%, n = 7) and neonatal severe compromise (15%, n = 8), leading to neonatal death in five cases. The overall survival rate after prenatal diagnosis of isolated SCT was 75% (n = 41 of 55). Earlier gestational age at diagnosis (P = 0.02), large tumor volume at referral (P < 0.001), presence of one or more hemodynamic complications (P = 0.02), fast tumor growth velocity (P < 0.001) and high tumor grade (highest tumor grade ≥ 3) (P = 0.049) were associated with poor perinatal outcome on univariate analysis. On stepwise logistic regression analysis, tumor growth velocity was the only remaining independent factor associated with poor perinatal outcome (odds ratio (OR) (per 1-mm/week increase), 1.48 (95% CI, 1.22-1.97), P = 0.001). The best predictive cut-off of tumor growth velocity for poor perinatal outcome was 7 mm/week (OR, 25.7 (95% CI, 5.6-191.3), P < 0.001), yielding a sensitivity of 88% and a specificity of 77%. CONCLUSIONS: Approximately 30% of fetuses with a diagnosis of isolated SCT have poor perinatal outcome. Tumor growth velocity ≥ 7 mm/week appears to be an appropriate discriminative cut-off for poor perinatal outcome. These results could help to inform prenatal management and counseling of parents with an affected pregnancy. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Pulsatile giant sacrococcygeal teratoma appearing like 2nd head.

Sacrococcygeal teratoma is a congenital tumor of early infancy. Eighty percent are present in the first month of life. It is considered to be an extragonadal germ cell tumor that can be diagnosed in utero. It is considered to be a rare tumor in infancy and childhood. Incidences in girls are more common as compared to boys. Association with other congenital abnormalities of the gastrointestinal system, cardiovascular system, and urological manifestations may be present. Association with spinal dysraphism may be present. A complete systemic evaluation needs to be done before any surgical intervention. We hereby present you a case of a 5-day-old male child, born from a non-consanguineous marriage, who presented to us with a large swelling at the coccygeal region. The mass had a variegated consistency with an ear-like appendage over it with associated hair, bones, and necrotic tissue in it. The patient was evaluated with imaging (MRI) which revealed a heterogeneously enhancing mass at the sacrococcygeal region with mild extension into the pre-sacral space suggesting sacrococcygeal teratoma. After a complete evaluation for congenital abnormal abnormalities of other sites, gross total excision of the mass was performed. The post-operative condition of the baby was uneventful. A biopsy of the mass revealed a mature cystic teratoma. The baby is under follow-up at present.

Prenatal diagnosis in estimating the prognosis of sacrococcygeal teratoma.

: Sacrococcygeal teratoma is a rare congenital malformation, the prognosis depends on factors affecting foetal development. The diagnosis is based on ultrasound examination, especially the evaluation of the detailed morphology of the foetus in the 20th week of pregnancy. Therefore, it is crucial to keep looking for ultrasound markers that would prenatally determine the most accurate prognosis for the foetus. Now, we rely on a small number of studies with a predominance of case reports. We offer a literature review of the essential information concerning sacrococcygeal teratoma diagnostics, therapy, and complications of sacrococcygeal teratomas in connection with prenatal diagnosis. It turns out that in cases with a favourable prognosis according to prenatal ultrasound examination and adequate surgical treatment after childbirth, the prognosis of this congenital malformation is excellent.

Prognostic accuracy of factors associated with poor outcome in prenatally diagnosed sacrococcygeal teratoma: A systematic review and meta-analysis.

Several factors associated with poor outcome in patients with prenatally diagnosed sacrococcygeal teratoma (SCT) have been found. However, the prognostic accuracy of these factors has not been well established. Therefore, we aimed to systematically review the prognostic accuracy of factors associated with poor outcome in these patients. We queried Search Premier, COCHRANE Library, EMCARE, EMBASE, PubMed, ScienceDirect, and Web of Science databases to identify studies regarding patients with prenatally diagnosed SCT. Poor outcome was defined as termination of pregnancy (TOP), intrauterine fetal death (IUFD), or perinatal death. We estimated the odds ratio of factors associated with poor outcome. Eleven studies (447 patients) were included. Overall mortality, including TOP, was 34.9%. Factors associated with poor outcome in fetuses with prenatally diagnosed SCT were cardiomegaly, hypervascular tumor, solid tumor morphology, fetal hydrops, and placentomegaly. A tumor volume to fetal weight ratio (TFR) of >0.12 before a gestational age of 24 weeks is predictive of poor outcome. The prognostic accuracy of factors associated with poor outcome in fetuses prenatally diagnosed with SCT seems promising. Factors associated with cardiac failure such as cardiomegaly, hypervascular tumor, solid tumor morphology, fetal hydrops, placentomegaly, and TFR >0.12 were found to be predictive of poor outcome.

Continuous ultrasound-guided sacral intervertebral block for postoperative analgesia in neonates.

A sacrococcygeal teratoma and a sacral agenesis represent a contraindication to a caudal block. We report two cases where the optimal use of ultrasound helped place a sacral intervertebral catheter in two neonates. Radiological and ultrasound studies of the sacrum and spine should be available before performing the procedure.

[Prenatal diagnosis and prognostic factors analysis of fetal sacrococcygeal teratoma].

Objective: To investigate the prenatal diagnosis and prognostic factors of fetal sacrococcygeal teratoma (SCT). Methods: A retrospective analysis was performed on 41 pregnant women who were diagnosed with fetal SCT by prenatal ultrasound at the Women's Hospital, Zhejiang University School of Medicine from January 2014 to September 2021. The prenatal imaging features and pregnancy outcomes, including tumor volume to fetal weight ratio (TFR), proportion of solid tumor, tumor growth rate (TGR), fetal hydrops, placentomegaly and polyhydramnios were analyzed. Receiver operating characteristic (ROC) curve was used to determine the critical values of TFR and TGR for predicting adverse fetal outcomes. Results: (1) Among the 41 pregnant women with fetal SCT, the diagnostic gestational week of ultrasound was (24.2±2.9) weeks (range: 18-28 weeks). Among them, 1 case progressed to fetal hydrops and induced labor at 22 weeks of gestation, 1 case developed intrauterine death and induced labor at 29 weeks of gestation, and 39 pregnancies continued until delivery. Among the 39 cases of continued pregnancy, 1 case underwent cesarean section at 31 weeks of gestation due to malignant polyhydramnios and increased fetal cardiothoracic ratio in the third trimester, 1 case underwent cesarean section at 32 weeks of gestation due to fetal heart failure, and 1 case underwent cesarean section at 32 weeks of gestation due to fetal heart failure and hydrops. The other 36 cases underwent surgical resection of tumor within 3 weeks after birth with good prognosis. (2) TFR>0.12 before 28 weeks of gestation could predict poor fetal prognosis, with a sensitivity of 100.0%, a specificity of 86.1% and an area under curve (AUC) of 0.922 (P<0.01). Among the fetuses with TFR>0.12, 5/10 had poor prognosis, while the fetuses with TFR≤0.12 all had good prognosis (100%,31/31), and the difference between the two groups was statistically significant (P<0.001). (3) TGR>48 cm3/week could predict poor fetal prognosis with a sensitivity of 100.0%, a specificity of 78.3% and an AUC of 0.880 (P<0.05). (4) Among the 28 SCT fetuses delivered in our hospital, the incidence rate of poor fetal prognosis was 0 (0/20) in those with solid tumor component<50%, and 5/8 in those with solid tumor component ≥50%, and the difference between the two groups was statistically significant (P<0.01). The incidence rate of poor fetal prognosis was 2/2 in those with placentomegaly (all with fetal hydrops), and 12% (3/26) in those without placentomegaly. The risk of poor fetal prognosis was 8.67 times higher in those with placentomegaly than those without placentomegaly, and the difference between the two groups was statistically significant (P<0.05). The incidence rate of poor fetal prognosis in those with polyhydramnios was 3/7, and 10% (2/21) in those without polyhydramnios, but there was no statistically significant difference between the two groups (P>0.05). Conclusion: TFR combined with solid tumor morphology, TGR, and presence of placentomegaly could predict the adverse pregnancy outcomes of fetal SCT.

A single-center experience of magnetic resonance imaging findings of fetal sacrococcygeal teratomas.

BACKGROUND: Sacrococcygeal teratomas (SCT) are known as rare tumors, but they are the most common tumor in fetuses and newborns. This study aims to present fetal magnetic resonance imaging (MRI) findings of SCT diagnosed prenatally and compare them with that of the prenatal Ultrasound (US) findings. METHODS: Eleven patients diagnosed as SCT prenatally by US and further assessed by MRI are included. MRI was performed via a 1.5-T magnet with a body coil. The presence, size, content extension, and compressive effects of each mass were determined and correlated with US findings and with postnatal examinations, including surgery and pathology. As complications, the presence of ascites and skin edema or pleural or pericardial effusion was diagnosed as hydrops. The amniotic fluid index was calculated for the assessment of oligo- or polyhydramnios. RESULTS: US findings are found strongly correlated with MRI findings. An agreement on the extent of each mass was observed in eight patients, disagreement in one fetus was an extension of the tumor within the spinal canal recognized only at MR and assessment of intrapelvic-abdominal extension was superior in MRI. There were n = 6 type I, n = 2 type II, n = 1 type III and, n = 2 type IV tumors. MRI was superior to US for detecting displacement of the colon (n = 3), intrapelvic-intraabdominal extension (n = 1), urinary tract complication (n = 2), and intraspinal extension (n = 1). DISCUSSION: MRI is found to be superior to US especially in the assessment of intrapelvic and intraspinal extension of the tumor, colonic displacement, and complications.

Solitary vaginal paraganglioma with mature sacrococcygeal teratoma: a rare case report.

BACKGROUND: Vaginal paraganglioma are rare, atypical, solitary tumors which originate from the female genital tract. Sacrococcygeal teratoma are also rare neoplasms which derive from one (or more) primordial germ cell layers. Here we report a unique case of vaginal paraganglioma with sacrococcygeal teratoma. CASE PRESENTATION: A 44-year-old female experienced paroxysmal hypertension, palpitations and dizziness for almost six years. Enhanced CT and MRI highlighted two abnormal soft tissue lesions located in the left vaginal wall and coccyx anteriorly, and Iodine-131 metaiodobenzylguanidine (131I-MIBG) demonstrated abnormal radioactive uptake in perineum area. Endocrine tests showed elevated plasma normetanephrine (NMN) and 24 h urine norepinephrine. There was a well-circumscribed soft tissue lesion of approximately 3.5 cm in the left lateral vaginal wall which could be palpated during bimanual examination, together with a 1.5 cm tumor in the posterior wall of the rectum. We completely resected the two lesions in stages with the support of a senior gynecologist and general surgeons. Postoperative histopathological examinations suggested the vaginal paraganglioma and mature sacrococcygeal teratoma. Targeted sanger sequencing for the 36 mostly common paraganglioma-related genes, with a depth of 1000x, revealed no mutations. Post-operatively, plasma NMN and 24 h urine norepinephrine returned to the normal range and her symptoms completely disappeared. CONCLUSIONS: We reported an extremely rare case and the successful treatment of functional vaginal paraganglioma coexisting with adult sacrococcygeal teratoma.

Factors associated with poor outcome in fetuses prenatally diagnosed with sacrococcygeal teratoma.

AIM OF THE STUDY: Outcome of fetuses, prenatally diagnosed with sacrococcygeal teratoma (SCT), is still poorly documented. This study assesses the incidence and prenatal predictors of outcome in all fetuses prenatally diagnosed with SCT. METHODS: This is a retrospective study on all fetuses prenatally diagnosed with SCT from 1998 to 2018 in the Netherlands. Poor outcome was defined as terminations of pregnancy (TOP) because of expected unfavorable outcome, intrauterine fetal death, or early neonatal death. Potential risk factors for poor outcome were analyzed. MAIN RESULTS: Eighty-four fetuses were included. Sixteen (19.0%) TOPs were excluded from statistical analysis. Eleven of the remaining 68 fetuses had poor outcome. Overall mortality was 32.1%, with a mortality excluding TOPs of 13.1%. Thirteen fetal interventions were performed in 11 (13.1%) fetuses. Potential risk factors for poor outcome were the presence of fetal hydrops (OR: 21.0, CI: 2.6-275.1, p = 0.012) and cardiomegaly (OR: 10.3, CI: 1.9-55.8, p = 0.011). CONCLUSIONS: The overall mortality of fetuses prenatally diagnosed with SCTs including tTOP was 32.1%. This high mortality rate was mainly due to termination of pregnancy. Mortality excluding TOP was 13.1%. Potential risk factors for poor outcome were fetal hydrops and cardiomegaly.

A rare case of fetus in fetu in the sacrococcygeal region: CT and MRI findings.

BACKGROUND: Fetus in fetu is a rare condition in which a malformed fetus is found in the body of a living twin. The retroperitoneum is the most common location of this condition. However, the sacrococcygeal region is a rare site of the disease. The presence of vertebral bodies and limbs differentiates FIF from teratoma. Imaging modalities are important for diagnosing FIF. CASE PRESENTATION: A 12-months old boy was hospitalized because of a mass in the sacrococcygeal region. CT showed a large, complex mass with bony structure resembling sacrococcygeal bone, hip bone and the femur in the sacrococcygeal region of the boy. The blood supply of the mass was from the aorta of the host. MRI revealed the mass was connected with the dilated sacral canal of the host, which resulted in tethered cord. A preoperative diagnosis of FIF was made and surgery was performed to remove the mass. Surgical removal and subsequent pathological examination revealed the anencephalic fetus had limb buds and a sacrum but no axial skeleton, which supported the diagnosis of FIF. Conclusions CT and MRI played important roles in diagnosing FIF based on the location of the lesion.

Description of a giant hypothalamic hamartoma associated with an immature ruptured giant sacrococcygeal teratoma: a case report.

Giant hypothalamic hamartomas (GHH) are rare neonatal intracerebral congenital malformations responsible for gelastic epilepsy and/or endocrine disturbances. Sacrococcygeal teratomas (SCT) are fetal neoplasms associated with perinatal morbidity and mortality, especially hemorrhagic complications in giant examples (GSCT). Here, we describe an immature ruptured GSCT complicated by hemorrhagic shock at 32-week gestation boy requiring an emergency delivery, followed immediately by urgent surgical removal. A brain lesion resembling a GHH was also present on the antenatal MRI. In order to exclude metastatic immature teratoma or glioma, a biopsy was performed by a retro-sigmoidal approach, which confirmed the nature of the hamartoma. Here, we describe for the first time the association of a ruptured immature GSCT associated with a GHH.

Imaging anatomy of the vertebral canal for trans-sacral hiatus puncture of the lumbar cistern.

A standard lumbar puncture may be impossible for many anatomic or technical reasons. Previous accounts of caudal epidural anesthesia and other procedures via the sacral hiatus prompted us to test if image-guided percutaneous trans-sacral hiatus access to the lumbosacral subarachnoid cistern would be anatomically feasible. To study vertebral canal morphometry and curvature, we analyzed midsagittal computed tomography-myelogram images of 40 normal subjects and digitally measured sacral curvatures between S1 to S5 and S2 to S4 using two methods whereby a lower angle signifies a straighter sacrum. We measured midsagittal vertebral canal area, hiatus width, dural sac termination levels, and distance from sacral hiatus to the dural sac tip (needle distance). Subjects were F:M = 25:15, with a mean age of 44.9 years. The two S1-S5 full sacral curvature mean angles were 57.3° and 60.4°. Almost all sacral hiatuses were at S4, and dural sac terminations were at S1-S2. The mean S2-S4 sacral curvature was 25.1°, and the mean needle distance was 57.7 mm. Using two-way analysis of variance, there were significant sex differences for needle distances (p = .001), and full and limited sacral curvatures (p = .02, and p = .046, respectively). There were no significant linear regression correlations between age and sacral curvature, needle distance, canal area, or hiatus width. Therefore, despite a frequently prominent full sacral curvature, the combination of S1-S2 dural sac termination plus a relatively straight trajectory of the lower vertebral canal between S2 and S4 support the theoretical feasibility of percutaneous trans-sacral hiatus and vertebral canal access to the lumbosacral cistern using a standard spinal needle.

Imaging Coccygeal Trauma and Coccydynia.

The coccygeal region has complex anatomy, much of which may contribute to or be the cause of coccyx region pain (coccydynia). This anatomy is well depicted at imaging, and management is often dictated by what structures are involved. Coccydynia is a common condition that is known to be difficult to evaluate and treat. However, imaging can aid in determining potential causes of pain to help guide management. Commonly, coccydynia (coccygodynia) occurs after trauma and appears with normal imaging features at static neutral radiography, but dynamic imaging with standing and seated lateral radiography may reveal pathologic coccygeal motion that is predictive of pain. In addition, several findings seen at cross-sectional imaging in patients with coccydynia can point to a source of pain that may be subtle and easily overlooked. Radiology can also offer a role in management of coccygeal region pain with image-guided pain management procedures such as ganglion impar block. In addition to mechanical coccyx pain, a host of other conditions involving the sacrococcygeal region may cause coccydynia, which are well depicted at imaging. These include neoplasm, infection, crystal deposition, and cystic formations such as pilonidal cyst. The authors review a variety of coccydynia causes, their respective imaging features, and common management strategies.©RSNA, 2020.

Analysis of magnetic resonance signal intensity changes in the sacrococcygeal region of patients with uterine fibroids treated with high intensity focused ultrasound ablation.

Objective: To evaluate the magnetic resonance (MR) signal intensity changes in the sacrococcygeal region of patients with uterine fibroids treated with high intensity focused ultrasound (HIFU).Materials and Methods: Two hundred and sixty-seven patients with uterine fibroids treated with HIFU between January and December 2016 were retrospectively reviewed. All patients underwent enhanced pre- and post-HIFU MRI. Multivariate analysis was used to assess the relationship between the factors and the signal intensity changes in the sacrum and the soft tissue adjacent to the sacrum.Results: Among the 267 patients, 122 (46%) had MR signal intensity changes in the sacrum and/or the soft tissue adjacent to the sacrum after HIFU. Multivariate analysis showed that the position of the uterus, the distance from the dorsal side of the fibroid to the sacrum, and the ablation efficiency were significantly correlated with MR signal intensity changes in the sacrum and the soft tissue adjacent to the sacrum. Further analysis showed a significant relationship between the location of the MR signal intensity changes and uterine size, the enhancement degree of the uterus. Leg pain was only seen in patients with MR signal intensity changes both in the sacrum and the soft tissue adjacent to the sacrum.Conclusions: The location of the uterus, the distance between the dorsal side of the fibroids to the sacrum, and ablation efficiency have a significant relationship with the MR signal intensity changes. The size of the uterus and the degree of enhancement are related to the locations of MR signal changes.

Sacrococcygeal teratoma in one twin: a case report and literature review.

BACKGROUND: Sacrococcygeal teratoma is one of the most common congenital tumors in newborns and infancy. The incidence is 1 per 20,000-40,000 live births. Ultrasonography is an optimal method for prenatal screening and diagnosis of fetal sacrococcygeal teratoma. MRI can be used to assist in the diagnosis. However, sacrococcygeal teratoma in the twin pregnancy is rare. CASE PRESENTATION: We reported a case of one twin with sacrococcygeal teratoma in dichorionic-diamniotic twin pregnancy.One twin with sacrococcygeal teratoma was diagnosed at the second trimester by ultrasonic examination and another twin was normal. A regular and careful antenatal care was conducted by the multidisciplinary team. The parents refused to perform the fetal MRI and examine the chromosome of both twin.At 37 + 1 of gestation, planned cesarean section was performed. The healthy male co-twin (twin A) weighed 2880 g.The male twin with SCT (twin B) weighed 2900 g, complying with 6 × 3 × 3 cm cystic and solid mass in sacrococcygeal region. At four days of age twin B underwent excisional surgery of the sacrococcygeal teratoma and coccyx and discharged 7 days after surgery. The mother and both babies were followed up and are all in good health until now. CONCLUSION(S): Sacrococcygeal teratoma in twin pregnancy is rare. Early antenatal diagnosis is important. Once the sacrococcygeal teratoma is diagnosed, clinicians should be aware of the associated maternal and fetal complications. Expecting parents should be counseled by the multidisciplinary team about the management and prognosis of the STC twin and co-twin. Prompt surgical excision of the sacrococcygeal teratoma after birth should be suggested.

Pregnancy in a woman with sacral agenesis from prenatal counseling to delivery: A case report.

Sacral agenesis or CRS (caudal regression syndrome) is a rare congenital condition involving approximately 1 in 25 000 live births (Sharma et al., 2015) and leading to the absence of lower sacral vertebral bodies and severe malformations of the pelvis. This condition is associated with an extreme reduction of the xipho-pubic distance and of the pelvic dimensions. It is reasonable to think that this might lead to an increased difficulty in obtaining a spontaneous pregnancy and to a consistently increased risk of maternal and perinatal complications. In literature, very little is known about pregnancy in patients with sacral agenesis and therefore on the appropriate way to counsel a patient with this condition who is trying to get pregnant (Greenwell et al., 2013). Although a case of pregnancy in a woman with sacral agenesis is mentioned in a book (J. Rogers, 2006) no cases of women with CRS carrying a pregnancy until a viable age for the fetus are reported in medical literature: as far as we know this is the first case reported in literature of a woman with this condition followed before and throughout the pregnancy with reported pre- and perinatal management, leading to a near-term pregnancy. This case could be useful for clinicians who are requested to counsel female patients with the same condition on the possibility of a pregnancy and possible outcomes.

Percutaneous Intratumor Laser Ablation for Fetal Sacrococcygeal Teratoma.

OBJECTIVE: To evaluate the efficiency of percutaneous intratumor laser ablation for fetal solid sacrococcygeal teratoma (SCT). SUBJECTS AND METHODS: We carried out percutaneous ultrasound-guided intratumor laser ablation through a 17-gauge needle using an output of 40 W in 7 fetuses with large solid SCT and reviewed the literature for minimally invasive therapy for this condition. RESULTS: Laser ablation was carried out at a median gestational age of 20 (range 19-23) weeks, and in all cases there was elimination of obvious vascularization within the tumor and improvement in cardiac function. Three (43%) babies survived and had surgical excision of the tumor within 2 days of birth, 3 liveborn babies died within 5 days of birth and before surgery, and 1 fetus died within 2 weeks after the procedure. In previous series of various percutaneous interventions for predominantly solid SCT the survival rate was 33% (2/6) (95% CI 9.7-70%) for endoscopic laser to superficial vessels, 57% (4/7) (95% CI 25-84%) for intratumor laser, 67% (8/12) (95% CI 39-86%) for intratumor radiofrequency ablation, and 20% (1/5) (95% CI 3.6-62%) for intratumor injection of alcohol. CONCLUSIONS: In solid SCT, the reported survival from intratumor laser or radiofrequency ablation is about 50%, but survival does not mean success, and it remains uncertain whether such interventions are beneficial or not because the number of fetuses is small and there were no controls that were managed expectantly.

Prenatal diagnosis of caudal regression with heterotaxy syndrome: "A mermaid with a broken heart".

Caudal regression syndrome (CRS) is a rare congenital malformation with varying degrees of early gestational developmental failure. It is characterized by agenesis of the sacrum and lumbar spine, with lower limb neurological deficit and accompanying deformities of the pelvis, lower extremities, genitourinary, and gastrointestinal systems. We report a case of CRS associated with rare complex congenital heart defect, that is, heterotaxy syndrome, diagnosed prenatally.

Pelvic occupation: the challenges of treating a symptomatic tarlov cyst.

Tarlov (perineural) cysts are meningeal dilations of the posterior spinal nerve root sheath located in between the peri- and endoneurium. We present a patient with a symptomatic sacral Tarlov cyst and the technical challenges faced by surgically treating the lesion by disconnection of the cyst from the subarachnoid space.