Inguinal lymph nodal metastasis of myxopapillary ependymoma confirmed by fine-needle aspiration cytology, biopsy, and immunohistochemistry: case report

Development and Validation of a Predictive Nomogram for Patients With Myxopapillary Ependymoma: A Surveillance, Epidemiology, and End Results (SEER) Retrospective Cohort Analysis

STUDY DESIGN

Retrospective Study.

OBJECTIVE

Myxopapillary ependymomas (MPEs) are a unique subgroup of spinal ependymomas originating from the filum terminale's ependymal glia. The 2021 WHO classification reclassified all MPEs as grade 2, recognizing their higher recurrence risk. Due to their rarity, our objective with this study is to understand MPEs' clinical course and optimal management through a large retrospective cohort analysis.

METHODS

From the years 2000 to 2020, patients with MPEs were identified from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariable Cox proportional hazard models were run to identify variables that had a significant impact on the primary endpoint of overall survival (OS). A predictive nomogram was built to predict 5-year and 10-year survival probability.

RESULTS

This retrospective cohort includes 1373 patients. Patients 65 years or older at diagnosis had a poorer OS (P < 0.001). Most patients received subtotal resection. Only 320 patients (23%) received gross total resection (GTR). Patients that received GTR had the best OS when compared against all other modalities of treatment (P < 0.05). Receiving radiotherapy did not affect OS in patients with MPE (P = 0.2). Nomogram includes patient age and treatment modalities, demonstrating acceptable accuracy in estimating the survival probability at 5-year and 10-year intervals, with a C-index of 0.80 (95% CI of 0.71 to 0.90).

CONCLUSION

This study highlights the survival benefit of GTR in the treatment of patients with MPE. The role of adjuvant radiotherapy remains unclear as it did not seem to improve OS. The nomogram stratifies the risk of survival in patients with MPE based on age and treatment modality.

Myxopapillary Ependymoma Metastasis Mimicking Pulmonary Embolism: An Illustrative Case

Myxopapillary ependymomas (MPEs) are rare spinal cord tumors with low rates of metastasis outside of the neuraxis. Gross total resection of MPEs can significantly improve progression-free survival; however, adjunctive treatment remains unstandardized. A 29-year-old female with a history of spina bifida occulta surgical correction and lower back pain presented with dyspnea and tachycardia. A large pulmonary artery mass was discovered consistent with pulmonary thromboembolism. It was subsequently determined to be an intravascular metastasis secondary to sacral MPE. Standardization of MPE treatment and clinical suspicion of spinal neoplasm in the setting of chronic back pain with undetermined origin are of value.

Clinical management and prognosis of spinal myxopapillary ependymoma: a single-institution cohort of 72 patients

PURPOSE

Myxopapillary ependymoma (MPE) was classified as grade 2 tumor in the 2021 World Health Organization central nervous system classification because of its high recurrence probability. This study aimed to investigate predictive factors and management of tumor recurrence.

METHODS

Seventy-two patients with spinal MPE underwent initial surgical treatment at our hospital between 2011 and 2021. Kaplan-Meier curves and Cox regression were used to analyze the correlation between clinical variables and progression-free survival (PFS).

RESULTS

The median age at diagnosis was 33.5 years (range 8-60 years). Twenty-one patients (29.2%) had preoperative spinal drop metastases. Gross total resection (GTR) was performed in 37 patients (51.4%). The median follow-up was 7.2 years, and the follow-up rate was 88.9% (64 of 72 cases). Twelve of the 64 patients (18.9%) relapsed, and preoperative drop metastasis occurred in 7 patients (58.3%). The estimated 5-year and 10-year PFS rates were 82% and 77%, respectively. Univariate analysis showed that GTR was associated with improved PFS (hazard ratio [HR] 0.149, p = 0.014), while preoperative drop metastasis (HR 3.648, p = 0.027) and tumor involvement sacrococcygeal region (HR 7.563, p = 0.003) were associated with tumor recurrence. Adjuvant radiotherapy (RT) was significantly associated with improved PFS in patients with preoperative drop metastasis (p = 0.039).

CONCLUSION

Complete surgical resection under the premise of protecting neurological function is an important factor in reducing spinal MPE recurrence. Adjuvant RT is recommended when the tumor invades the capsule with preoperative drop metastasis or adhesion to the nerve and cannot reach GTR.

Anaplastic myxopapillary ependymoma: A case report and review of literature

BACKGROUND

Myxopapillary ependymoma (MPE) is a pathological grade I tumor that arises in the filum terminale. MPE with anaplastic features is extremely rare, and only 5 cases have shown malignancy at the time of recurrence.

CASE SUMMARY

The patient (a 46-year-old woman) had undergone a MPE operation 30 years ago. After subtotal resection of the tumor located in L4-S1, it had a solid component that extended to the adjacent subcutaneous region. Histologically, the tumor consisted of a typical MPE with anaplastic features. The anaplastic areas of the tumor showed hypercellularity, a rapid mitotic rate, vascular proliferation, and connective tissue proliferation. Pleomorphic cells and atypical mitotic figures were occasionally observed. The MIB-1 index in this area was 12.3%. The immunohistochemical study showed immunoreactivity for vimentin, glial fibrillary acidic protein and S100. The morphological pattern and immunohistochemical profile were consistent with anaplastic MPE. The patient tolerated surgery well without new neurological deficits. She underwent local irradiation for the residual tumor and rehabilitation.

CONCLUSION

Although extremely rare, anaplastic MPE occurs in both pediatric and adult patients, similar to other ependymomas. At a minimum, close monitoring is recommended, given concerns about aggressive biological potential. In the future, further study is needed to determine the WHO classification criteria and genetic indicators of tumor progression. The possibility of malignant transformation of MPE should be taken into account, and patients with MPE should be treated with care and follow-up.

Surgical management of a rare myxopapillary ependymoma of the gluteal region: A case report

Background:

Ependymomas are rare tumors originating from neuroepithelial cells lining the wall of the ventricles or central canal of the spinal cord. While these tumors mainly occur within the central nervous system (CNS), there are occasional reports in children and young adult patients with a primary tumor occurrence outside of the CNS. Ependymomas of the sacrococcygeal region have been infrequently described in the literature with no standard of care established. We present a case report and review of the literature regarding this rare entity.

Case Description:

A 24-year-old woman presented with right gluteal pain worsened by sitting and a palpable soft tissue mass of the sacrococcygeal region. Magnetic resonance imaging revealed a 3.7 cm cystic mass centered in the right gluteal region. She underwent a biopsy at an outside institution, with histology revealing myxopapillary ependymoma. The patient was referred to our hospital and underwent an interdisciplinary neurosurgical and orthopedic oncology en bloc resection of the ependymoma, which intraoperatively appeared to originate from the coccygeal nerve.

Conclusion:

In the present report, the authors demonstrate that a myxopapillary ependymoma may present as an isolated gluteal mass attached to the coccygeal nerve, without frank CNS involvement. Furthermore, an interdisciplinary approach to surgical resection of this lesion appears to represent an effective treatment modality.

Clinicopathologic features of anaplastic myxopapillary ependymomas

Myxopapillary ependymomas (MPE) are considered benign (World Health Organization (WHO) grade I) neoplasms with favorable prognosis. However, malignant behavior occurs in a small subset. To our knowledge, only five anaplastic MPEs have been reported without consensus on diagnostic criteria. We retrieved 14 anaplastic MPEs from the pathology archives of six institutions. Each tumor included at least two of the following features: ≥5 mitoses per 10 high power fields, Ki-67 labeling index (LI) ≥10%, microvascular proliferation (MVP) and spontaneous necrosis. These features were typically encountered in the foci of hypercellularity and reduced mucin. There were eight male and six female patients (age range 6-57 years, median = 16.5). Ten tumors displayed anaplasia at initial resection, and 4 were anaplastic at a second surgery for recurrence (ranging from 9 months to 14 years following initial resection). The Ki-67 LI ranged between 8% and 40% in the anaplastic foci and <3% in the foci of classic MPE. There was documented cerebrospinal fluid (CSF) dissemination in seven cases, recurrence following an anaplastic diagnosis in three cases and bone or soft tissue invasion in two cases. One patient suffered lung metastases. Two cases evaluated by targeted next-generation sequencing and one evaluated by fluorescence in situ hybridization (FISH) showed nonspecific chromosomal gains. We conclude that although rare, anaplastic MPE occurs in both pediatric and adult patients, similar to other ependymomas. At a minimum, closer follow-up is recommended, given the concern for aggressive biologic potential. Further study is needed to determine WHO grading criteria and genetic indicators of tumor progression.

Extraneural metastasis of ependymoma in the cauda equina

We report a rare case of extraneural metastasis of spinal ependymoma that developed over a very long period. A 28-year-old man underwent surgery for ependymoma in the cauda equina. After he experienced three local recurrences and had undergone five operations, a lung metastasis occurred 46 years after the first operation. Although the tumor did not show the typical morphological malignancy, the maximum standard uptake value obtained by positron-emission tomography and the antigen Ki-67 labeling index demonstrated the tumor's active proliferative ability. One year after the last operation, the patient died of respiratory failure due to progressing lung metastases. The malignant behavior of spinal ependymomas is demonstrated in a case with long-term follow-up.