Myxopapillary ependymoma of the posterior mediastinum

When a dermatopathologist encounters the ultra-rare: A case series of superficial soft tissue/cutaneous myxopapillary ependymomas

Myxopapillary ependymoma (MPE) is an uncommon variant of ependymoma, almost exclusively seen in conus medullaris or filum terminale. MPE can be diagnostically challenging, especially when arising extra-axially. Here we report 5 cases of superficial soft tissue/cutaneous MPE, identified across three tertiary institutions. All patients were female and three of them (3/5, 60%) were children (median age 11 years, range 6-58 years). The tumors presented as slow-growing masses of the sacrococcygeal subcutaneous soft tissues, occasionally identified after minor trauma and clinically favored to be pilonidal sinuses. Imaging showed no neuraxis connection. Macroscopically, tumors were well-circumscribed, lobulated, and solid and microscopically they exhibited typical histopathology of MPE, at least focally. Two of the tumors (2/5, 40%) showed predominantly solid or trabecular architecture with greater cellular pleomorphism, scattered giant cells, and increased mitotic activity. All tumors (5/5, 100%) showed strong diffuse immunohistochemical expression of GFAP. One tumor clustered at the category "ependymoma, myxopapillary" by methylome analysis. Two patients (2/5, 40%) had local recurrence at 8 and 30 months after the initial surgery. No patients developed metastases during the follow-up period (median 60 months, range 6-116 months). Since a subset of extra-axial MPEs behaves more aggressively, timely and accurate diagnosis is of paramount importance.

Overexpression of Long Noncoding RNA HOTAIR Is a Unique Epigenetic Characteristic of Myxopapillary Ependymoma

Ependymomas are a heterogeneous group of central nervous system tumors. Despite the recent advances, there are no specific biomarkers for ependymomas. In this study, we explored the role of homeobox (HOX) genes and long noncoding RNA (LncRNA) HOTAIR in ependymomas along the neural axis. Bioinformatics analysis was performed on publicly available gene expression data. Quantitative RT-PCR was used to determine the mRNA expression level among different groups of ependymomas. RNA in situ hybridization (ISH) with probes specific to HOTAIR was performed on tumor tissue microarray (TMA) constructed with 19 ependymomas formalin-fixed paraffin-embedded tissue. Gene expression analysis revealed higher expression of posterior HOX genes and HOTAIR in myxopapillary ependymoma (MPE), in comparison to other spinal and intracranial ependymoma. qRT-PCR confirmed the high HOXD10 expression in spinal MPEs. There was a significant upregulation of HOTAIR expression in spinal MPE and elevated HOTAIR expressions were further confirmed by RNA ISH on the TMA. Intriguingly, HOXD10 and HOTAIR expressions were not elevated in nonependymoma spinal tumors. Our collective results suggest an important role for the lncRNA HOTAIR and posterior HOX genes in the tumorigenesis of spinal MPE. HOTAIR may also serve as a potential diagnostic marker for spinal MPE.

Neurogenic Tumors of the Mediastinum

Neurogenic tumors represent a broad ill-defined category of neoplasms that includes tumors of Schwann cell and/or neuroblastic derivation, as well as neoplasms that typically develop in the central nervous system, but rarely present in ectopic sites including the mediastinum. Neurogenic tumors may occur at many different anatomic sites, but the mediastinum represents a uniquely challenging site given the complex anatomy. Additionally, some of these neoplasms may present with multicentric involvement in the context of genetic syndromes, including NF1, NF2 and schwanomatosis. Most of these develop in posterior structures, often in association with paraspinal structures. Fine needle biopsy/small biopsies play an important role in the diagnosis of these neoplasms, given its record of safety and the increased applicability of ancillary testing to these smaller samples at the present time. In this review we focus on the major categories of neurogenic tumors that may be encountered in the mediastinum, including schwannoma, neurofibroma, malignant peripheral nerve sheath tumors, ganglioneuroma and ganglioneuroblastoma, as well as rarer members of this category. We discuss diagnostic approaches applicable to small cytologic and tissue samples and relevant differential diagnoses.

A case of bi-focal mediastinal ependymoma

Ependymomas are tumors located in the central nervous system, mostly in the brain and spinal cord. This tumor is rarely seen as a primary mediastinal location. The aim of this study is to discuss this rare pathology in the clinical course of an unusual case. A 47-year-old female patient was referred to our clinic with the complaint of back and shoulder pain, via VATS posterior mediastinum located paravertebral mass excision was performed. The pathology reported as ependymoma. Two years later, CT scans of the routine control showed the well-defined mass in anterior mediastinum. The SUVmax of the lesion was measured as 9.3 at PET-CT. The lesion in the anterior mediastinum was excised by partial sternotomy. The pathology result was the same as the prior operation: Ependymoma. As our case, in these kinds of tumors meticulous follow-up of the patients is important for the detection and treatment of recurrent localization and distant metastases.

Primary mediastinal ependymoma: A case report and literature review

RATIONALE

Ependymomas are neuroepithelial tumors that typically occur in the central nervous system. Ependymomas arising in the mediastinum are exceedingly rare, with only approximately 9 isolated cases reported in the literature to date.

PATIENT CONCERNS

A 35-year-old woman was referred to our hospital with complaints of progressive back pain for 3 months. Physical examination revealed decreased breathing sounds and tenderness. Contrast-enhanced computed tomography showed a soft tissue mass with heterogeneous enhancement in the right posterior mediastinum.

DIAGNOSES

The diagnosis of primary mediastinal ependymomas (PMEs) was confirmed by postoperative histopathologic examination.

INTERVENTIONS AND OUTCOMES

The patient underwent surgical resection of the tumor and experienced local recurrence with neck metastasis 2 years postoperatively. She underwent reoperation for the recurrent tumors and received postoperative radiotherapy and adjuvant chemotherapy. Two years later, the patient is doing well, with no evidence of tumor progression or recurrence.

LESSONS

Since PMEs are exceedingly rare, treatment options are limited. Surgical resection seems to be the mainstay of treatment. Further evidence-based studies are required to prove the benefit of radiotherapy and chemotherapy in the treatment of PMEs.

Giant intradural extramedullary spinal ependymoma, a rare arachnoiditis-mimicking condition: case report and literature review

Background and importance: Ependymomas are tumours arising from the ependymal cells lining the ventricles and the central canal of the spinal cord. They represent the most common intramedullary spinal cord tumour in adults and are very rarely encountered in an extramedullary location. Only 40 cases of intradural extramedullary (IDEM) ependymomas have been reported, all of which were diagnosed pre-operatively as IDEM ependymomas on contrast-enhanced MRI. Clinical presentation: We report a 23-year old male presenting with rapidly worsening signs and symptoms of spinal cord disease. A spinal MRI demonstrated a posterior multi-cystic dilatation extended between T1 and T12. Post-contrast sequences showed peri-medullar leptomeningeal enhancement and the diagnosis of spinal arachnoiditis was made. The patient underwent surgery and the spinal cord appeared circumferentially wrapped by an irregular soft tissue. The tissue was sub-totally removed and the pathological diagnosis was ependymoma WHO grade II. The patient experienced an excellent neurological recovery and no further treatments were administered. A small residue is now stable at 2.5 years follow-up. Conclusions: Giant IDEM ependymomas are rare entities and pre-operative diagnosis can be challenging in some cases. Surgery represents the main treatment option being resolutive in most cases.

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.

Pituitary Ependymoma: A Case Report and Review of the Literature

BACKGROUND

Pituitary ependymoma is exceptionally rare. Its etiology, clinical presentation, radiologic feature, and treatment strategy are still a matter of debate. Only 7 human cases with limited data were reported in the English literature, and now we described another case of pituitary ependymoma. We also systematically reviewed previously reported cases and described its potential etiology, clinical presentation, radiologic features, pathology, immunohistochemical analysis, and ultrastructural examinations.

CASE DESCRIPTION

A lesion in pituitary fossa was discovered in a 40-year-old man after suffering a progressive deterioration of vision in his right eye for >1 year with intermittent headache. The lesion was microsurgically resected and proved to be ependymoma upon pathologic and histologic examination. The patient made a fully recovery after surgery.

CONCLUSIONS

To our knowledge, only 7 patients with ependymoma in the sellar region have been described in the English literature. We reported 1 more case of pituitary ependymoma and discussed the potential etiology, clinical presentation, radiologic features, pathology, immunohistochemical analysis, ultrastructural examinations, treatment, surgery, radiotherapy, chemotherapy, and prognosis of pituitary ependymoma. The case report may serve as a helpful reference for clinicians and radiologists.

Intraocular Ependymoma With Blood-Filled Spaces: Neoplasm or a Reactive Process With Ependymal Differentiation-A Dilemma

Intraocular glial lesions are rare and include retinal gliosis, hamartomas, and astrocytomas and rarely ependymomas. Ependymomas are slow-growing glial tumors preferentially arising in the central nervous system (CNS), occasionally presenting at sites outside the CNS, with only 2 cases of primary retinal ependymoma reported till date. We report herein the third such case of a 20-year-old male who presented with a painful blind eye. The enucleated specimen showed presence of a glial tumor with cells arranged in sheets as well as few true rosettes and pseudo-rosettes and an immunohistochemical profile similar to a classical ependymoma at usual sites in the CNS. Additionally, the presence of blood-filled spaces and few proliferating blood vessels made it a diagnostic challenge. All retinal glial lesions are positive for GFAP and S100. Therefore, immunostaining for EMA as well as the MIB-1-labeling index maybe vital in differentiating ependymomas from other intraocular glial lesions.

Occipital Intraparenchymal Myxopapillary Ependymoma: Case Report and Literature Review

Myxopapillary ependymoma (MPE) is a histological variant of ependymoma found in the conus medullaris or filum terminale region. Intracranial occurrence of the tumor is a rarity. The most characteristic histological feature of myxopapillary tumors is the abundance of intercellular and perivascular mucin and the arborizing vasculature, which tends to form papillae. We are reporting a 14-year-old patient presented with seizures caused by the right occipital region intraparenchymal lesion. Histopathology confirmed it to be MPE. Lesion was excised completely. Literature reviews on the topic are discussed regarding the histological findings, natural history, and outcome of surgically treated MPE. This is the fifth reported case of cerebral intraparenchymal primary MPE.

Pelvic Ependymoma With Clinical Response to GnRH Analog Therapy: A Case Report With an Overview of Primary Extraneural Ependymomas

Extraneural ependymomas are rare tumors that occur in sacrococcygeal, pelvic and extra pelvic regions. While sacrococcygeal extraneural ependymomas are equally distributed among males and females, pelvic and extra pelvic ependymomas have been exclusively reported in women, mainly of child bearing age. We present a case of extraneural, pelvic ependymoma that showed clinical response to GnRH therapy with its immunohistochemical and electron microscopic analysis, and an overview of primary extraneural ependymomas based on a review of all such cases published in English literature.

Mesenchymal tumours of the mediastinum--part II

This is the second part of a two-part review on soft tissue tumours which may be encountered in the mediastinum. This review is based on the 2013 WHO classification of soft tissue tumours and the 2015 WHO classification of tumours of the lung, pleura, thymus and heart and provides an updated overview of mesenchymal tumours that have been reported in the mediastinum.

Intradural Extramedullary Primary Ependymoma of the Craniocervical Junction Combined with C1 Partial Agenesis: Case Report and Review of the Literature

BACKGROUND

Intramedullary ependymomas represent 40%-60% of spinal cord tumors in adults and can be located along the entire spinal cord. Intradural extramedullary (IDEM) ependymomas are very rare with the exception of tumors located at the filum terminale or conus medullaris, with histologic features of myxopapillary ependymomas (World Health Organization grade I).

CASE DESCRIPTION

We present the case of a 42-year-old woman with an IDEM ependymoma of the craniocervical junction who experienced neck pain for 5 months. Magnetic resonance imaging of the cervical spine and craniocervical junction showed a large IDEM solid-cystic lesion with anterolateral junction spinal cord compression. A preoperative computed tomography scan did not show any calcified lesion, although a partial agenesis of the C1 posterior arch was observed. During surgery, a well-encapsulated IDEM tumor without dural attachment or medullary infiltration was found, and a total en bloc excision was performed. Histologic examination revealed a grade II ependymoma. The patient had an excellent clinical recovery, with no recurrence after 2 years of follow-up.

CONCLUSIONS

To the best of our knowledge, no other cases of craniocervical junction ependymomas with vertebral bone abnormalities are described in the literature. This association supports the hypothesis that these lesions may originate from the extrusion of ependymal cells before neural tube closure. Differential diagnosis should include other extramedullary tumors that are more frequent in this region, such as meningioma, schwannoma, or dermoid tumor.

Osteolytic myxopapillary ependymoma with marked hyaline degeneration in a 72-year-old male: A case report

Myxopapillary ependymomas (MPEs) are uncommon and account for ∼15% of all ependymomas. The current study presents a case of rare spinal MPE with abnormal hyaline degeneration. The patient was a 72-year-old male with a 10-month history of lower back pain. Magnetic resonance imaging revealed a mass involving the L4 and L5 vertebrae with local bone destruction. The tumor was completely resected. Histologically, the majority of the tumor exhibited low cellularity. A marked change in hyaline was observed in the blood vessels and stroma. In specific areas, the tumor showed reticular or tubular patterning embedded in hyaline materials. The tumor cells were cuboidal to columnar in shape with strong immunostaining for glial fibrillary acidic protein and S-100. A fluorescence in situ hybridization analysis for amplification of the epidermal growth factor receptor gene was negative. The results of pathological and immunohistochemical studies were consistent with the ependymal nature of neoplastic cells.

Stabilization of metastatic myxopapillary ependymoma with sorafenib

We report on a 59-year old woman with three huge intrathoracal masses that were accidentally diagnosed when she consulted a physician for upper abdominal discomfort. A biopsy revealed that they were metastases of a coccygeal myxopapillary ependymoma, resected 20 years before. As neither resection, debulking, nor radiation therapy were considered to be indicated, systemic therapy with temozolomide was started. At the first evaluation after four months, the metastases had progressed. Imatinib delayed the progression, but had to be stopped after six months because of critical increased pleural effusion. Using the multikinase inhibitor sorafenib, the disease was stabilized and an acceptable quality of life could be obtained for one year.

Neurogenic tumors of soft tissue

Neurogenic tumors are an uncommon yet important category of soft tissue tumors in children and adolescents because of their frequent association with various genetic syndromes. The heterogeneous cellular composition of the peripheral nerve and the wide metaplastic capacity of the neural crest and its derivatives generate a variety of neoplasms with neurogenic differentiation. This article reviews the clinicopathologic features and differential diagnosis of neurogenic tumors in the first two decades of life, and highlights use of selected ancillary methods for diagnosis.

Extramedullary ependymoma near the conus medullaris with lumbar nerve root attachment: case report

BACKGROUND AND IMPORTANCE

Ependymomas are the most common primary spinal cord tumor, most frequently located near the cauda equina and conus medullaris. We believe that this is the first reported case of a low-grade, nonmyxopapillary (World Health Organization grade 2), intradural, extramedullary ependymoma involving a spinal nerve root.

CLINICAL PRESENTATION

An 87-year-old woman presented with a chief complaint of acute onset of severe right hip and lateral thigh pain without midline back pain. She had baseline chronic bladder dysfunction, which remained unchanged. Her physical examination was significant for 4/5 strength in her right hip flexion (possibly related to pain), and 5 beats of clonus bilaterally. She had no point tenderness at the level of her compression fracture. Computed tomography of the patient's lumbar spine revealed a well-corticated, chronic compression fracture of the L3 vertebral body. Magnetic resonance images demonstrated an ovoid-shaped, 1.5×1-cm, well-circumscribed, intradural, extramedullary lesion at the conus medullaris. The patient underwent an L1-3 laminectomy with intradural resection of the mass, which was found to be intricately involved with a single nerve root. The nerve root was coagulated and sectioned, and a gross total resection of the tumor was achieved.

CONCLUSION

The patient tolerated the procedure well, with no complications or any postoperative neurological deficit. Her right-sided pain immediately resolved after surgery. Her strength and ambulation were normal after surgery. No adjuvant radiotherapy was offered to the patient. This case illustrates a unique tumor presentation and the successful surgical treatment of the condition.

Primary Myxopapillary Ependymoma of the Medulla

OBJECTIVE

Myxopapillary ependymoma is a subclassification of ependymoma that is thought to be nearly exclusive to the conus medullaris or filum terminale. Primary intracerebral or brainstem myxopapillary ependymomas are rare.

CLINICAL PRESENTATION

An 8-year-old child presented with a 5-month history of nausea and vomiting and a 1-week history of headache. Magnetic resonance imaging revealed a nodular mass in the medulla with an associated cyst extending into the fourth ventricle.

INTERVENTION

A suboccipital craniotomy was performed, and a gross total resection of the lesion and cyst was achieved. Histological examination confirmed the diagnosis of myxopapillary ependymoma. A discussion of other reported cases of extraspinal myxopapillary ependymomas is presented.

CONCLUSION

This is the first report of a case of myxopapillary ependymoma, confirmed by histology, in the medulla. Although rare, myxopapillary ependymomas outside of the filum terminale do exist.

Chordoma of the sacrum and vertebral bodies

Chordomas are relatively rare tumors of bone. These primary malignant lesions occur throughout the spinal column and often show advanced growth at the time of diagnosis. Because such tumors are minimally responsive to radiation and chemotherapy, surgical resection is the mainstay of treatment. Patient survival and local control are associated with the ability to achieve wide surgical margins during excision. However, surgical morbidity may be substantial given the propensity for chordomas to abut or surround neural, vascular, and visceral structures. Thus, early recognition is essential, and treatment by a multidisciplinary team is ideal.

Ependymoma of the sella turcica: a variant of pituicytoma

A broad spectrum of neoplasms affects the sellar region. Among these, gliomas are rare, most being tumors of pituicytes such as granular cell tumor and pituicytoma. Only 4 ependymomas of the human sellar region have been reported to date and all have had classic histologic features. Herein, we describe the clinicopathologic features of a sellar, low-grade ependymoma with unusual histology, but classic ultrastructural features, occurring in an elderly patient and thus expanding the spectrum of reported cases. The literature is reviewed and concepts of histogenesis are explored, particularly an origin in "ependymal pituicytes." The concept that sellar ependymoma is pituicyte-derived is explored.