Tanycytic ependymoma of the filum terminale associated with multiple endocrine neoplasia type 1: first reported case

A Cohort Study of CNS Tumors in Multiple Endocrine Neoplasia Type 1

PURPOSE

Multiple endocrine neoplasia type 1 (MEN1) is thought to increase the risk of meningioma and ependymoma. Thus, we aimed to describe the frequency, incidence, and specific clinical and histological features of central nervous system (CNS) tumors in the MEN1 population (except pituitary tumors).

EXPERIMENTAL DESIGN

The study population included patients harboring CNS tumors diagnosed with MEN1 syndrome after 1990 and followed up in the French MEN1 national cohort. The standardized incidence ratio (SIR) was calculated based on the French Gironde CNS Tumor Registry. Genomic analyses were performed on somatic DNA from seven CNS tumors, including meningiomas and ependymomas from patients with MEN1, and then on 50 sporadic meningiomas and ependymomas.

RESULTS

A total of 29 CNS tumors were found among the 1,498 symptomatic patients (2%; incidence = 47.4/100,000 person-years; SIR = 4.5), including 12 meningiomas (0.8%; incidence = 16.2/100,000; SIR = 2.5), 8 ependymomas (0.5%; incidence = 10.8/100,000; SIR = 17.6), 5 astrocytomas (0.3%; incidence = 6.7/100,000; SIR = 5.8), and 4 schwannomas (0.3%; incidence = 5.4/100,000; SIR = 12.7). Meningiomas in patients with MEN1 were benign, mostly meningothelial, with 11 years earlier onset compared with the sporadic population and an F/M ratio of 1/1. Spinal and cranial ependymomas were mostly classified as World Health Organization grade 2. A biallelic MEN1 inactivation was observed in 4/5 ependymomas and 1/2 meningiomas from patients with MEN1, whereas MEN1 deletion in one allele was present in 3/41 and 0/9 sporadic meningiomas and ependymomas, respectively.

CONCLUSIONS

The incidence of each CNS tumor was higher in the MEN1 population than in the French general population. Meningiomas and ependymomas should be considered part of the MEN1 syndrome, but somatic molecular data are missing to conclude for astrocytomas and schwannomas.

Beyond the "3 Ps": A critical appraisal of the non-endocrine manifestations of multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 1 (MEN1), an autosomal-dominantly inherited tumor syndrome, is classically defined by tumors arising from the "3 Ps": Parathyroids, Pituitary, and the endocrine Pancreas. From its earliest descriptions, MEN1 has been associated with other endocrine and non-endocrine neoplastic manifestations. High quality evidence supports a direct association between pathogenic MEN1 variants and neoplasms of the skin (angiofibromas and collagenomas), adipose tissue (lipomas and hibernomas), and smooth muscle (leiomyomas). Although CNS tumors, melanoma, and, most recently, breast cancer have been reported as MEN1 clinical manifestations, the published evidence to date is not yet sufficient to establish causality. Well-designed, multicenter prospective studies will help us to understand better the relationship of these tumors to MEN1, in addition to verifying the true prevalence and penetrance of the well-documented neoplastic associations. Nevertheless, patients affected by MEN1 should be aware of these non-endocrine manifestations, and providers should be encouraged always to think beyond the "3 Ps" when treating an MEN1 patient.

An update on the CNS manifestations of brain tumor polyposis syndromes

Cancer predisposition syndromes are associated with an increased risk of developing primary malignancies. Here we discuss those which are associated with an increased risk of tumors of the central nervous system (CNS) and gastrointestinal (GI) tract. These can be grouped into those in which the CNS tumors predominate versus those in which the GI cancers predominate. The former include constitutional mismatch repair deficiency (CMMRD) syndrome, Li-Fraumeni syndrome (LFS), and Cowden syndrome (CS) while the latter include familial adenomatosis polyposis 1 (FAP1), Lynch syndrome and polymerase proofreading-associated polyposis syndrome (PPAP). Tumor specificity does exist as medulloblastoma occur in FAP, LFS and CMMRD while glioma are most commonly seen in all replication repair-deficient genes and LFS. Choroid plexus carcinoma is strictly observed in LFS while Cowden syndrome patients develop Lhermitte Duclos disease or meningioma. In each syndrome, specific types of low-grade and high-grade gastrointestinal cancers can occur, but these will be discussed elsewhere. Underlying cancer predisposition syndromes are important to consider when faced with brain tumors, particularly in the pediatric and young adult age groups, as identification of an underlying germ line mutation may change the upfront management of the patient and has implications for future cancer surveillance for both the patient and potentially affected family members. Considerations of family history, presence of skin lesions and consanguinity provide valuable information in identifying patients at potential increased risk.

Extramedullary tanycytic ependymoma of the lumbar spinal cord

Tanycytic ependymoma is a rare variant of ependymoma that commonly affects the cervical and thoracic spinal cord. It usually arises as intramedullary lesions, and extramedullary cases are extremely rare. We report a case of a 44-year-old woman who was diagnosed with tanycytic ependymoma in her lumbar spine at level 2-3. The tumor mass developed in an intradural extramedullary location. Histopathologically, tanycytic ependymoma can be misdiagnosed as schwannoma or pilocytic astrocytoma. Immunohistochemical findings such as strong positivity for glial fibrillary acidic protein, perinuclear dot-like positive patterns for epithelial membrane antigen, and focal positivity for S100 protein are helpful in diagnosing tanycytic ependymoma. It is important to be aware of this rare tumor to ensure appropriate patient management and accurate prognosis.

Tanycytic ependymoma of filum terminale: Clinical characteristics and surgical outcomes

Tanycytic ependymoma (TE), a rare subtype of ependymoma, was classified as grade II ependymoma by the World Health Organization in 2000 and 2007. Preoperative diagnosis of TE is challenging due to its similarities to schwannoma and astrocytoma; therefore, differentiation is required. The present study investigated the clinical, imaging and pathological characteristics of TE in the filum terminale. A retrospective analysis was conducted on the clinical, imaging, pathological and immunohistochemical characteristics of 8 patients with TE in the filum terminale and the relevant literature was reviewed. Of the 8 patients 7 were female and 1 was male, with an age range of 24–62 years old. The primary clinical symptom observed was lumbago, accompanied by lower limb pain and numbness. Magnetic resonance imaging predominantly identified isointensity on thoracic (T) 1-weighted images and iso- or hyperintense signal intensity on T2-weighted images, with homogeneous or inhomogeneous enhancement. All patients underwent resection of the tumor through a posterior median approach, and total resection was acighieved in 7 patients. During postoperative follow-up, all patients experienced improvement compared with their preoperative status, and were without tumor recurrence. The present study comprised the largest group of cases with TE in the filum terminale reported so far, to the best of our knowledge, which could foster a better understanding of this disease. Complete surgical resection of the tumor has the greatest effectiveness of any treatment for TE in the filum terminale. Postoperative histological examination, immunohistochemistry and electron microscopy for tumor specimens may assist in its diagnosis and differential diagnosis.

Resistance-promoting effects of ependymoma treatment revealed through genomic analysis of multiple recurrences in a single patient

As in other brain tumors, multiple recurrences after complete resection and irradiation of supratentorial ependymoma are common and frequently result in patient death. This standard-of-care treatment was established in the pregenomic era without the ability to evaluate the effect that mutagenic therapies may exert on tumor evolution and in promoting resistance, recurrence, and death. We seized a rare opportunity to characterize treatment effects and the evolution of a single patient's ependymoma across four recurrences after different therapies. A combination of high-depth whole-genome and exome-based DNA sequencing of germline and tumor specimens, RNA sequencing of tumor specimens, and advanced computational analyses were used. Treatment with radiation and chemotherapies resulted in a substantial increase in mutational burden and diversification of the tumor subclonal architecture without eradication of the founding clone. Notable somatic alterations included a MEN1 driver, several epigenetic modifiers, and therapy-induced mutations that impacted multiple other cancer-relevant pathways and altered the neoantigen landscape. These genomic data provided new mechanistic insights into the genesis of ependymoma and pathways of resistance. They also revealed that radiation and chemotherapy were significant forces in shaping the increased subclonal complexity of each tumor recurrence while also failing to eradicate the founding clone. This raises the question of whether standard-of-care treatments have similar consequences in other patients with ependymoma and other types of brain tumors. If so, the perspective obtained by real-time genomic characterization of a tumor may be essential for making effective patient-specific and adaptive clinical decisions.

The Clinical Features and Surgical Outcomes of Spinal Cord Tanycytic Ependymomas: A Report of 40 Cases

OBJECTIVE

Spinal cord tanycytic ependymomas (TEs) rarely are reported because of extremely low incidence. Understanding of this disease is therefore poor. The aim of this study was to analyze the incidence and clinical, radiologic, pathologic, and prognostic features of spinal cord TEs.

METHODS

Approximately 4000 spinal cord tumors were resected surgically in Beijing Tiantan Hospital between April 2009 and May 2016. We identified all cases of pathologically proved TEs among these patients.

RESULTS

TEs accounted for approximately 1% of spinal cord tumors (40 of an estimated 4000). Patients with TE were a mean age of 40.0 years and had no significant sex preference (21 male and 19 female). The median diameter of the maximal tumor was 54.2 mm (range, 16-153 mm). The mean preoperative Japanese Orthopedic Association (JOA) score was 13.0. Radiologically, 47.5% (19/40) cases showed poorly defined tumor border, and 40% (16/40) of them showed preoperative syringomyelia. Gross total resection was achieved in 30 cases, subtotal resection in 8, and partial resection in 2. At the time of discharge, JOA score and neurologic function showed improvement in 26 cases (65%), no change in 12 cases (30%), and worsening in 2 cases (5%). At a median follow-up of 43 months (range, 7-101 months), 1- and 5-year progression-free survival rates were 100.0% and 97.5%, respectively. Only one patient had tumor recurrence which was found 30 months after surgery. No patient died of tumor recurrence. At the latest follow-up, JOA score showed improvement in 30 cases (75%), no change in 8 cases (20%), and worsening in 2 cases (5%). Univariate analysis revealed that tumor size and preoperative JOA score were significantly associated with the short-term outcomes. Meanwhile, age ≥40 years, tumor size ≥50 mm, non-gross total resection, and preoperative JOA score <14 were significantly associated with an increased risk of worsened long-term outcomes. Poorly defined tumor border and preoperative JOA score <14 significantly limited the extent of tumor resection.

CONCLUSIONS

Spinal cord TE is a rare subtype of ependymomas with low recurrence. Long-term survival can be expected, although poorly defined tumor border is an independent predictor of long-term outcomes. Microsurgical treatment of spinal cord TEs remains a formidable challenge due to the poorly defined border and critical neurovascular structures encasement. It is unnecessary for radical tumor resection at the cost of severe neurologic deficits.

Imaging features of spinal tanycytic ependymoma

Tanycytic ependymoma is an unusual morphological variant of WHO grade II ependymoma, typically arising from the cervical or thoracic spinal cord. Although the literature deals extensively with pathological features of this tumour entity, imaging features have not been well characterised. The purpose of this study was to review magnetic resonance imaging (MRI) features of spinal tanycytic ependymomas reported in the literature to date, exemplified by a case of a patient with tanycytic ependymoma of the conus medullaris presenting to our hospital. A Medline search of the English literature for all previously published cases of spinal tanycytic ependymoma was carried out and the reported MRI features reviewed. The tumours were found to be typically well-demarcated masses, predominantly showing isointensity on T1-weighted signal, and T2-weighted hyperintensity, with variable patterns of contrast enhancement. A cystic component was seen in half of the cases, and in a minority a mural nodule was present within the cyst wall. Associated syrinx formation was observed in one-third of the cases and haemorrhage was rare, which may be helpful pointers in differentiating the lesion from other ependymoma subtypes. In conclusion, MRI characteristics of spinal tanycytic ependymoma are variable and non-specific, and radiological diagnosis thus remains challenging, although certain predominant features are identified in this report. Knowledge of these is important in the diagnostic differentiation from other intramedullary and extramedullary spinal tumours in order to guide appropriate surgical management.

Ependymoma and carcinoid tumor associated with ovarian mature cystic teratoma in a patient with multiple endocrine neoplasia I

Ovarian teratomas rarely undergo new neoplastic transformation and account for a small percentage of malignant ovarian germ cell neoplasms. Here we report a case of a 51-year-old woman with multiple endocrine neoplasia type I (MEN I) who was found to have an ependymoma and neuroendocrine tumor (trabecular carcinoid) associated with mature cystic teratoma of her left ovary. The ependymoma component displayed cells with round nuclei and occasional small nucleoli which were focally arranged in perivascular pseudorosettes and true rosettes. Rare mitoses were identified. No necrosis was present. Immunohistochemical staining was positive for S-100 and GFAP. The Ki67 proliferation index was very low (2-3%). In contrast, the endocrine tumor component was composed of small uniform cells with eosinophilic cytoplasm, round nuclei, and speckled chromatin. Immunohistochemical staining was positive for synaptophysin and focally positive for chromogranin. This rare case illustrates that MEN I may have an influence on the pathogenesis of ovarian teratomas as they undergo malignant transformation.