Paraganglioma of the filum terminale internum. Report of a case and review of the literature

Cauda equina neuroendocrine tumor: a report of three cases and review of the literature with focus on differential diagnosis and postoperative management

INTRODUCTION

Cauda equina neuroendocrine tumors (CENETs), previously described as cauda equina paragangliomas (PGLs) are rare and well-vascularized benign entities which can be often misdiagnosed with other intradural tumors more common in this anatomical site, such as ependymomas and neurinomas. We describe three cases of CENETs observed at our institution with particular focus on differential diagnosis and postoperative management. Since the lack of guidelines, we performed a literature review to identify factors that can predict recurrence and influence postoperative decision making.

CASE REPORT AND LITERATURE REVIEW

We report on three patients, two of them presenting with a clinical history of lower back pain and sciatica. In all cases magnetic resonance imaging (MRI) of the lumbosacral spine with and without Gd-DTPA revealed an intradural lesion with strong contrast enhancement, first described as atypical ependymoma or schwannoma. A complete tumor resection was achieved in all cases, the histopathological diagnosis classified the tumors as CENETs. In our literature review, a total of 688 articles were screened and 162 patients were included. Patients demographic data, clinical symptoms, resection and recurrence were recorded.

DISCUSSION

Differential diagnosis between CENETs and other more common tumors affecting cauda equina region, such as ependymomas or schwannomas (neurinomas), is still very challenging. Due to the lack of specific clinical or radiological characteristics, a correct preoperative diagnosis is almost impossible. With this paper we want to point out that CENETs must be considered in the differential diagnosis, most of all in case of entities with atypical radiological features. According to the literature, tumor recurrence after gross total resection is unlikely, while a long-term follow-up is recommended in case of subtotal resection or local aggressive behavior.

The isolation, differentiation, and survival in vivo of multipotent cells from the postnatal rat filum terminale

Neural stem cells (NSCs) are undifferentiated cells in the central nervous system (CNS) that are capable of self-renewal and can be induced to differentiate into neurons and glia. Current sources of mammalian NSCs are confined to regions of the CNS that are critical to normal function and surgically difficult to access, which limits their therapeutic potential in human disease. We have found that the filum terminale (FT), a previously unexplored, expendable, and easily accessible tissue at the caudal end of the spinal cord, is a source of multipotent cells in postnatal rats and humans. In this study, we used a rat model to isolate and characterize the potential of these cells. Neurospheres derived from the rat FT are amenable to in vitro expansion in the presence of a combination of growth factors. These proliferating, FT-derived cells formed neurospheres that could be induced to differentiate into neural progenitor cells, neurons, astrocytes, and oligodendrocytes by exposure to serum and/or adhesive substrates. Through directed differentiation using sonic hedgehog and retinoic acid in combination with various neurotrophic factors, FT-derived neurospheres generated motor neurons that were capable of forming neuromuscular junctions in vitro. In addition, FT-derived progenitors that were injected into chick embryos survived and could differentiate into both neurons and glia in vivo.

Recurrent paraganglioma of Meckel's cave: Case report and a review of anatomic origin of paragangliomas

BACKGROUND

Paragangliomas are rare, usually benign tumors of neural crest origin. They account for only 0.6% of all head and neck tumors. In the craniocervical area, they are more common in the carotid body and tympanico-jugular regions. To the authors' knowledge, a case of paraganglioma in Meckel's cave has not yet been reported in the medical literature. The pathogenesis and natural history of paragangliomas are still not well understood. We present a case of recurrent paraganglioma in Meckel's cave.

CASE DESCRIPTION

A 53-year-old woman was diagnosed with trigeminal neuralgia, dysesthesia and hypoesthesia on the left side of the face, hearing disturbance and a history of chronic, persistent temporal headaches. Magnetic resonance imaging (MRI) showed a lesion located in Meckel's cave on the left side, extending to the posterior cranial fossa and compressing the left cerebral peduncle. The lesion was first thought to be a recurrence of an atypical meningioma, as the pathologist described it in the tissue specimen resected 3 years earlier, and a decision for re-operation was made. A lateral suboccipital approach to the lesion was used under neuronavigational guidance. The tumor was removed, and histological examination proved the lesion to be a paraganglioma. Five months later, the follow-up MRI showed local regrowth, which required subsequent surgical intervention.

CONCLUSIONS

A paraganglioma in Meckel's cave is an uncommon tumor in this location. Although ectopic paragangliomas have been described in the literature, a paraganglioma atypically located in Meckel's cave makes a topographic correlation difficult, mainly because paraganglionic cells are usually not found in Meckel's cave. Another peculiarity of the case is the local recurrence of the tumor in a relatively short time despite an attempted, almost gross total resection.

Paragangliomas of the lumbar region

✓ The author reports two cases of cauda equina paraganglioma (CEP) and provides a review of all previously published cases. The current radiological, neurosurgical, and pathological literature on this rare tumor is also reviewed.

Malignant cauda equina paraganglioma in a cat

An 11-year-old spayed female domestic long-haired cat presented for surgical removal of a slowly growing and deeply invasive 2.5 x 3.5-cm mass cranial to the base of the tail. Light microscopic examination of surgical biopsy specimens revealed an encapsulated mass composed of packets of polygonal cells of various sizes separated by a delicate fibrovascular stroma. Gömöri's reticulum stain revealed a characteristic endocrine or "Zellballen" pattern. Tumor cells contained diffuse positive reactivity to synaptophysin and neuron-specific enolase, reactions consistent with a neuroendocrine neoplasm. S-100 protein-positive cells reminiscent of sustentacular (support) cells occurred singly or in small clusters within tumor packets. At postmortem examination 3 months later, a 9- x 5- x 4-cm multinodular raised tan mass involving the caudal pelvis, sacrum, and tail-head regions was found. The base of this neoplastic mass originated within the cauda equina region and involved approximately five caudal nerve roots. Numerous 1-3-mm metastatic nodules were identified disseminated throughout the pulmonary parenchyma. The tumor was diagnosed as a malignant paraganglioma of the cauda equina region with pulmonary metastasis.

Hemodynamic activity associated with a paraganglioma of the cauda equina. Case report

A 53-year-old man presented with a paraganglioma of the cauda equina that caused significant hemodynamic instability during removal. The clinical implications of this phenomenon are discussed.

Cervical paraganglioma with subsequent intracranial and intraspinal metastases. Case report

Paragangliomas, tumors derived from the extra-adrenal paraganglion system, have commonly been found in the retroperitoneum, abdomen, mediastinum, skull base, and neck. Rare intraspinal cases have included involvement of the cauda equina and filum terminale, and a recent case has been reported of thoracic cord paraganglioma with metastasis to the cauda equina. The authors present the case of a patient with a cervical paraganglioma who underwent subtotal resection followed by postoperative irradiation; she subsequently developed multiple intracranial and intraspinal metastases 7 months following the first decompression procedure.

Paraganglioma of the cauda equina. Report of 2 cases and review of 59 cases from the literature

Paragangliomas of the cauda equina are not so rare as said in the literature. Two additional cases are presented with a global analysis of the 59 cases from the literature. The diagnosis of this pathology greatly benefit of the use of immunostainings as the cells are often neuron-specific enolase, neurofilament protein and somatostatin positive so that electron microscopy is thus no longer mandatory for establishing the diagnosis. In addition, we report the first magnetic resonance images of this tumor at this location.