According to existing literature, the incidence of meningiomas worldwide is approximately 3-4 cases per 100,000 people annually, and meningiomas account for about 15-20% of all intracranial tumors. Among them, CCM represents less than 1% of all meningioma cases., they predominantly affects children. Pathologically, it is characterized by clear polygonal cells that are rich in glycogen (1, 2). Since the first case of CCM was reported in 1990, an increasing number of cases have shown that, compared to ordinary meningiomas, this type of tumor has a higher local recurrence rate and a more aggressive clinical course (3, 4). For these reasons, the World Health Organization (WHO) classified CCM as a Grade II tumor in 2016 (5).Intraspinal CCM are rarer than their intracranial counterparts (6). Moreover, in younger patients, these tumors may exhibit more aggressive behavior and are associated with a poorer prognosis (7), and tend to have a higher recurrence rate (8). Unlike intracranial CCM, the role of adjuvant radiotherapy following surgery for intraspinal CCM remains controversial. Current viewpoint suggests that for patients with intraspinal CCM, immediate postoperative radiotherapy may not be necessary following gross total resection, particularly in pediatric patients, owing to their lower tolerance for the side effects of radiotherapy (9–11). To date, GTR of intraspinal CCM is considered the optimal treatment for reducing recurrence rates and achieving longer progression-free survival (PFS) and overall survival (OS) (10, 12). Currently, the literature reports that intraspinal CCM predominantly occurs in the lumbar spine (6) with very fewer cases involving the upper cervical spine. Additionally, the role of radiotherapy in the management of intraspinal CCM remains controversial, particularly in pediatric patients, there still lack of detailed case reports on the treatment outcomes of this rare condition, especially in cases without dural attachment. Here, we present a case of a ventral upper cervical CCM without dural attachment, providing a detailed account of its clinical features, imaging characteristics, and intraoperative details, along with long-term follow-up results. Also, we conduct a literature review of reported cases of spinal canal CCM to explore diagnosis, treatment, and prognosis.

CCM has a higher recurrence rate and more aggressive biological behavior than typical meningioma (13). And has potential for metastasis and associated low progression-free survival rates (14). Unlike typical meningioma, which commonly occur in the thoracic spine, spinal CCM tends to involve the lumbar spine, with some cases showing evidence of bone destruction (15). Clinically, spinal CCM presents similarly to other intradural extramedullary tumors and lacks specific distinguishing features. Symptoms are typically related to the tumor’s location, size, and extent of its involvement with the spinal cord or nerve. Genetic studies have shown that besides NF2 mutations, loss of SMARCE1 may also associated with CCM. However, additional studies are needed to clarify the mechanisms underlying SMARCE1-related clear cell meningioma development (16). MRI is an effective preoperative diagnostic tool for spinal CCM. According to the literature, the imaging characteristics of most intradural CCMs resemble those of typical meningioma (14). They typically present as well-demarcated, round or oval intradural-extramedullary masses with isointense signals on both T1- and T2-weighted images. These tumors commonly display a broad dural attachment and show homogeneous enhancement after gadolinium administration, with some patients exhibiting a dural tail sign. However, some cases lack of dural attachment (17), making preoperative MRI prone to misdiagnosis as “schwannoma”. In addition, these tumors may exhibit aggressive features such as vertebral body destruction or invasion of the intervertebral foramen, mimicking malignant tumors (15, 18). Additionally, there have been reports of intramedullary CCMs (19). In summary, preoperative imaging lacks specificity, and definitive diagnosis still relies on postoperative pathological examination.

Current research suggests that the postoperative recurrence rate of intraspinal CCM can reach 40% (20). Therefore, reducing the recurrence rate and prolonging PFS are significant challenges for neurosurgeons. Chaim et al. suggested that adjuvant radiotherapy may help lower the recurrence risk in patients with a high Ki-67 index (21). Kobayashi et al. proposed that en bloc resection of the tumor without disrupting the capsule during surgery can prevent the dissemination of tumor cells. Furthermore, they identified positive PR expression via postoperative pathology as a potential predictor of favorable prognosis (22). Compared to conventional CCM, non-dural attached intradural spinal CCMs are more easily completely resected. Zhang et al. suggest that the recurrence rate of this specific type of meningioma is lower than that of other types. Nevertheless, adjuvant radiation therapy is still recommended (6). However, there is still no consensus on whether routine postoperative radiotherapy should be applied after GTR in pediatric patients (11).

We reviewed all well-documented cases of intraspinal CCM ( Supplementary Table S1 ), and analyzed factors such as patient age, sex, imaging characteristics, extent of surgical resection, postoperative pathology, and recurrence. We found that intraspinal CCMs typically involve the lumbar spine, particularly the cauda equina, while cervical spine involvement is rare. To date, fewer than five cases involving the cervical spine have been reported. Here, we report a case of an intradural-extramedullary cervical spine CCM in a child, which were the second well-documented case of cervical CCM in a pediatric patient, and the first case where the lesion was located on the ventral side of the upper cervical spine, mimicking a schwannoma both on preoperative imaging and under the surgical microscope. The World Federation of Neurosurgical Societies (WFNS) does not have specific guidelines exclusively for adjuvant radiotherapy in CCM. However, general recommendations for meningiomas of WHO grade II, which includes CCM, suggest considering adjuvant radiotherapy when GTR is not achieved. This approach is recommended to reduce recurrence rates. In CCM, the decision to use adjuvant radiation typically depends on tumor resectability and recurrence risk, especially when surgical margins are compromised or if there is nodular recurrence. In this case, given the patient’s pediatric age and complete encapsulated resection, adjuvant radiotherapy was not administered. The patient was followed for two years with no evidence of tumor recurrence.

This case report provides valuable insights into the rare occurrence of intradural-extramedullary cervical spinal CCM in a pediatric patient, contributing to the limited literature on such patients. However, the case is limited by its rarity, limiting generalizability, and the absence of preoperative genetic profiling, which could provide further insight into the molecular mechanisms of CCM. Additionally, while the two-year follow-up period is promising, a longer follow-up would be essential to fully evaluate long-term recurrence risk. More detailed radiological findings and further research on genetic markers are needed to enhance understanding and management of CCMs.

I was diagnosed with a rare condition, intraspinal CCM, located in my cervical spine. Initially, the doctors were unsure of the diagnosis, as the tumor resembled a schwannoma on the MRI images. It was a very overwhelming experience for me and my family, as we were concerned about what this might mean for my future health. However, after undergoing surgery, the tumor was completely removed, and the doctors were confident about the success of the procedure. The surgery was challenging, but I felt well-supported by the medical team throughout the process. They explained everything clearly, making sure I understood the procedure and recovery steps. Post-surgery, I had some discomfort and fatigue, but it was manageable. Fortunately, because my tumor was fully encapsulated and I was a child, the decision was made not to undergo radiotherapy. This relieved me of some concerns about the side effects of radiation, especially since I was already recovering from surgery. Over the next two years, I had regular check-ups, and I am happy to report that I have not experienced any tumor recurrence. I feel incredibly fortunate that I was able to receive the best care possible. Looking back, it has been a challenging but ultimately positive journey, and I am hopeful for my future. For other patients facing similar situations, I would encourage them to stay hopeful, trust their medical team, and stay focused on recovery.

Intraspinal CCM, particularly in the pediatric upper cervical spine, is extremely rare, with only a few cases reported in the literature. However, it should be considered an important differential diagnosis for spinal intradural lesions. This is because both preoperative imaging and intraoperative microscopic examination can lead to misdiagnosis of schwannoma. Despite its aggressive nature and high recurrence rate, the role of adjuvant radiotherapy post-surgery remains controversial. Currently, complete surgical resection and vigilant follow-up are essential for managing these patients.