SUBCUTANEOUS SACROCOCCYGEAL MYXOPAPILLARY EPENDYMOMA A Case Report and Review of the Literatures

A case of myxopapillary ependymoma originating in the soft tissue is described. The tumor was located subcutaneously over the coccyx of an 11-year-old girl but was connected neither to the filum terminale nor cauda equina. Clinically, the tumor was locally resected with a diagnosis of pilonidal cyst. Histological and electron microscopic findings were identical to myxopapillary ependymoma. The tumor cells showed a positive reaction by immunoperoxidase method (PAP method) of glial fibrillary acidic protein (GFAP). ACTA PATHOL. JPN. 35 : 925–931, 1985.     

Myxopapillary ependymoma with anaplastic features

A case of myxopapillary ependymoma with anaplastic features in 15-year-old boy is reported. The tumor was located in the intradural space extending to the 12th thoracic to 2nd lumbar vertebral level. It was excised with the accompanying spinal arch of the T12 to L2 vertebra. At operation, the tumor was not attached to the surrounding soft and bony tissues. The tumor, measuring 49 x 19 x 15 mm, was brownish-yellow in color and involved the conus medullaris and filum terminale. Histologically, the tumor was composed of biphasic features of a hypercellular papillary growth area and a hypocellular myxoid area. In the papillary growth area, ependymal rosettes and perivascular pseudorosettes were observed. These findings were consistent with those of a myxopapillary ependymoma, although multiple foci of punctate necrosis within the tumor and proliferation of endothelial cells showing glomeruloid structures were observed. Many mitotic figures were also observed. In addition, the Ki-67 labeling index of tumor cells was 10.1%. These findings are unusual for myxopapillary ependymoma, and therefore, it appeared that the diagnosis of myxopapillary ependymoma with anaplastic features was appropriate.     

Cerebral myxopapillary ependymoma.

A rare case of myxopapillary ependymoma is reported. The tumor occurred in the cerebral hemisphere of an 8-year-old girl and had no relationship to the lateral ventricles. Microscopically, it showed abundant mucin production around papillary or reticular structures. Immunohistochemically, these tumor cells were weakly positive, with glial fibrillary acidic protein demonstrated in part of the tumor and vimentin strongly demonstrated throughout the tumor. The results may indicate the poorly differentiated nature of this tumor. This is the second reported case of intracranial myxopapillary ependymoma.     

Extradural sacrococcygeal myxopapillary ependymoma

Histological and electron microscopic evidence has been obtained on a rare tumor--extradural sacrococcygeal myxopapillary ependymoma which was detected in two boys. A 5-year-old had a malignant recurrent tumor localized presacrally and metastatic to the lungs. The other boy aged 9 developed a benign subcutaneous tumor.     

Primary extraneural myxopapillary ependymoma of the broad ligament

Primary extraneural ependymomas are rare tumors that arise in ectopic sites, including pulmonary, sacrococcygeal region, ovarian, and paraovarian tissues. Four such ependymomas reported in the literature involve the paraovarian tissues, including 2 broad ligament ependymomas. Here we describe a myxopapillary ependymoma of the broad ligament in a 22-year-old woman, which may be the first tumor of this type to be reported in this location. Cytology, histology, cytochemistry, immunohistochemistry, and flow cytometry ploidy analysis are studied and described. Identification of perivascular ependymal rosettes, ependymal canals, vimentin and glial fibrillary acidic protein immunoreactivity, cytochemical staining of blepharoplasts or terminal bars by phosphotungstic acid hematoxylin, and presence of multiple foci of myxoid degeneration among the ependymal rosettes characterized a myxopapillary ependymoma.     

MYXOPAPILLARY EPENDYMOMA OF THE LATERAL VENTRICLE

Reported was the first case of myxopapillary ependymoma arising from the right lateral ventricle of a 29-year-old Japanese male. The histological and ultrastructural findings were identical to those from the filum terminale.
It was suggested that insudation of plasma proteins found within hyaline-thickened blood vessels in the tumor stroma represented the presence of previous long-standing anoxia and thus, circulatory disturbance would be closely related to the formation of the stromal myxoid change.     

Myxopapillary ependymoma of the lateral ventricle. A study on the mechanism of its stromal myxoid change

Reported was the first case of myxopapillary ependymoma arising from the right lateral ventricle of a 29-year-old Japanese male. The histological and ultrastructural findings were identical to those from the filum terminale. It was suggested that insudation of plasma proteins found within hyaline-thickened blood vessels in the tumor stroma represented the presence of previous long-standing anoxia and thus, circulatory disturbance would be closely related to the formation of the stromal myxoid change.     

Subcutaneous myxopapillary ependymoma presenting as a childhood sacrococcygeal tumor: a case report

Subcutaneous myxopapillary ependymoma in a sacrococcygeal location is an uncommon lesion. We report such a case in a 16-mo-old female child, who presented with a sacrococcygeal mass since birth. The cytological picture was that of a malignant small round cell tumor and the diagnosis was missed on cytology, which was retrospectively confirmed on comparison with histology. Although rare, this lesion can be a potential diagnostic pitfall and needs to be distinguished from other malignant tumors occurring at this age and at a similar location, like sacrococcygeal teratoma with immature elements, primitive neuroectodermal tumor (PNET), and PNET with ependymal differentiation.     

Microtubular aggregates within rough endoplasmic reticulum in myxopapillary ependymoma of the filum terminale

Aggregates of microtubules with-in rough endoplasmic reticulum were found in many neoplastic cells of three cases of myxopapillary ependymoma of the filum terminale studied ultrastructurally. The cytoplasm and cellular processes of some neoplastic cells were distended by the aggregates. In general the involved rough endoplasmic reticulum contained three to six microtubules, but some enclosed more than 10 microtubules. The enclosed microtubules were straight parallel hollow cylindrical structures with fuzzy coats. They had an inner diameter of 12 to 15 nm, an outer diameter of 30 to 35 nm, and a center-to-center distance of 50 to 62 nm. The involved rough endoplasmic reticulum often showed various degrees of loss of surface ribosomes and some appeared totally degranulated. Vacuolar degeneration of involved rough endoplasmic reticulum with fragmentation and disintegration of the enclosed microtubules was frequent. Direct relationship of the enclosed microtubules to the cytoplasmic microtubules and ciliary formation was not found. This unusual microtubular aggregate has not been described in other types of ependymoma, or in other brain tumors. They may represent a characteristic ultrastructural feature of myxopapillary ependymoma.     

Mediastinal myxopapillary ependymoma primary or late metastases of paracoccygeal ependymoma: a case report

A 25-year-old woman presented in 2002 with progressive shortness of breath and weight loss. A computed tomographic scan of the chest showed a huge anterior mediastinal mass, and pathological examination of a mediastinoscopic needle biopsy revealed typical myxopapillary ependymoma, an extremely unusual diagnosis at this site. Further workup and questioning of the patient revealed that she had opted not to disclose a history of surgery for right gluteal fold mass in 1993, which was primarily treated with surgery followed by radiotherapy for relapse. Review of the histology of the excised mass showed a myxopapillary ependymoma, similar to current histology. Clinical examination of the local gluteal and paracoccygeal site, computed tomographic imaging, and magnetic resonance imaging failed to demonstrate any evidence of recurrent disease in soft tissue or bone. The case is presented, and this very unusual presentation is discussed.     

cIMPACT‐NOW update 7: advancing the molecular classification of ependymal tumors

Advances in our understanding of the biological basis and molecular characteristics of ependymal tumors since the latest iteration of the World Health Organization (WHO) classification of CNS tumors (2016) have prompted the cIMPACT‐NOW group to recommend a new classification. Separation of ependymal tumors by anatomic site is an important principle of the new classification and was prompted by methylome profiling data to indicate that molecular groups of ependymal tumors in the posterior fossa and supratentorial and spinal compartments are distinct. Common recurrent genetic or epigenetic alterations found in tumors belonging to the main molecular groups have been used to define tumor types at intracranial sites; C11orf95 and YAP1 fusion genes for supratentorial tumors and two types of posterior fossa ependymoma defined by methylation group, PFA and PFB. A recently described type of aggressive spinal ependymoma with MYCN amplification has also been included. Myxopapillary ependymoma and subependymoma have been retained as histopathologically defined tumor types, but the classification has dropped the distinction between classic and anaplastic ependymoma. While the cIMPACT‐NOW group considered that data to inform assignment of grade to molecularly defined ependymomas are insufficiently mature, it recommends assigning WHO grade 2 to myxopapillary ependymoma and allows grade 2 or grade 3 to be assigned to ependymomas not defined by molecular status.     

Fine-needle aspiration of metastatic sacrococcygeal myxopapillary ependymoma

A 45-yr-old white woman with a 24-yr history of sacrococcygeal myxopapillary ependymoma developed a large metastasis of scalp and skull diagnosed as metastatic ependymoma on fine-needle aspiration, based on cytologic features, histologic pattern in cell block fragments, and a positive reaction with the glial fibrillary acidic protein immunoperoxidase study. The fine-needle study obviated the need for biopsy in this case, for which a surgical approach was considered to be inappropriate due to the extent of the process demonstrated by various imaging techniques.     

小儿室管膜瘤临床病理研究

对２３例小儿室管膜瘤进行了临床病理分析，其中男１７例，女６例，平均年龄８．８岁。２３例中肿瘤位于幕上者７例，幕下者１６例，术前平均病程分别为５．３个月和３个月。依据肿瘤的组织学特点，此瘤可分为乳头型（或粘液乳头型）、上皮型和多细胞型；依据肿瘤分化程度，可分为分化型和间变型室管膜瘤。２３例中有１７例胶质纤维酸性蛋白（ＧＦＡＰ）免疫组化染色呈阳性反应，其余６例为阴性。讨论了小儿室管膜瘤的临床病理特点、影响患者预后的因素及其组织学分类。     

Clonal Telomeric Fusions and Chromosome Instability in a Subcutaneous Sacrococcygeal Myxopapillary Ependymoma

Subcutaneous sacrococcygeal myxopapillary ependymoma (SSME) is a very rare neurologic tumor with no demonstrable connection to the spinal column. Little is known of its etiology, clinical characteristics, or cytogenetics. Giemsa-band analysis revealed a stemline karyotype showing 62 chromosomes. Sidelines within the tumor showed clonal telomeric fusions resulting in dicentric chromosomes involving the fusion of numerous chromosomes. Recurrent telomeric fusions resulted in the progressive deletion of chromosome bands 11q25 and 11q23 and subsequently the entire long arm. This is the first case of a SSME to show clonal cytogenetic aberrations. However, of greater interest is the demonstration of the clonal progression of telomeric fusions resulting in dicentric chromosomes and the subsequent loss of chromosome arms. The observation of clonal telomeric breakage/fusion cycles as progenitor lesions to subsequent deletions provides evidence for telomeric association as an intermediate step in the progression of chromosomal instability.     

Cytologic differential diagnosis of myxoid and mucinous neoplasms of the sacrum and parasacral soft tissues

A diagnostically important group of lesions involving the sacrum, spinal canal, and parasacral soft tissues is characterized by a myxoid or mucinous background in cytologic smears. This group of myxoid/mucoid neoplasms includes chordoma, myxopapillary ependymoma, metastatic mucinous adenocarcinoma, and extraskeletal myxoid chondrosarcoma. Despite the similarity of the background substance, each neoplasm within this differential diagnosis has a characteristic composite set of morphologic and immunophenotypic features. Because many of these masses are not easily surgically biopsied, fine-needle aspiration (FNA) is often used for their diagnosis. The private consultation records of the author and the cytology files of the University of Utah Department of Pathology were searched for all lesions arising in or around the sacrum. These cases were reviewed to determine which had a myxoid/mucinous background. Fourteen neoplasms were found and comprise the study set. Four of these cases had cell block material in addition to Diff-Quik-stained smears; a panel of antibodies, including cytokeratin, glial fibrillary acid protein (GFAP), S-100 protein, and carcinoembryonic antigen (CEA), was performed on the cell block material. The smears were evaluated for cytologic features, including the presence of rosette-like structures, physaliphorous cells, gland-like structures, chondroid fragments, "signet ring" and "goblet" cells, as well as the character of the myxoid/mucinous background substance.The cases included one myxopapillary ependymoma, 10 chordomas, two mucinous adenocarcinomas of colonic or gastric origin, and one myxoid chondrosarcoma. Physaliphorous cells were found to be highly specific for chordoma, while a fibrillary myxoid stroma containing cells with elongated cytoplasmic processes and cells lying in a rosette-like pattern around central cores of myxoid to fibrillary stroma were highly characteristic of myxopapillary ependymoma. Fragments of a myxoid/chondroid matrix with lacunar-like spaces strongly supported the diagnosis of myxoid chondrosarcoma. "goblet" or "signet ring" cells with a single distinct vacuole favored mucinous adenocarcinoma. There appear to be sufficient cytomorphologic features present within the FNA smears and cell block material to allow cytologic separation of the more common myxoid and mucinous neoplasms involving the sacral and parasacral tissues.     

Leukemia as a second malignancy

To study the occurrence of leukemia as a second malignancy following various primary solid and hematological malignancies. Total 11 cases of leukemia presenting as a second malignancy were studied over a period of 15 years from 1990 to 2005. The primary malignancies included carcinoma breast (4), multiple myeloma (3) and one each of Hodgkin's lymphoma, mediastinal germ cell tumor, papillary carcinoma thyroid and myxopapillary ependymoma. Ten patients had received chemotherapy with combination radiotherapy in six patients. The commonest type of leukemia was AML-M2. The cyogenetic test results were available in three cases. The secondary leukemia showed aggressive behaviour and all patients on follow-up died within a period of one month. The risk benefit ratio of chemotherapy and radiotherapy should be considered before starting the patients on treatment. A high degree of suspicion and follow up with hematological parameters is required for therapy related complications.     

Giant cell ependymoma-report of three cases and review of the literature

Ependymomas constitute the most common type of primary spinal cord tumors, and are subclassified as myxopapillary ependymoma, classic ependymoma, and anaplastic ependymoma. Ependymomas can be further subclassified based on morphologic phenotype: cellular, papillary, tanycytic, clear cell, pigmented and epithelioid. Giant cell ependymoma (GCE), a rare variant, has recently been described. Reported cases have exhibited a wide anatomic distribution, including spinal cord, cerebrum and cerebellum. We report here three cases of GCE, arising from cerebrum in a 5-year-old girl, spinal cord in a 34-year-old female and cerebellum in an 86-year-old female respectively. Histologically those cases showed prominent pleomorphic giant cells with focal perivascular pseudorosettes in all cases. Tumor cells were immunopositive for GFAP and EMA. Only the first case was qualified for anaplastic ependymoma. No recurrence was noted in these three cases after 57, 46 and 6 months of follow-up respectively. By reviewing the literature, GCEs arising from spinal cord and cerebellum tended to have low-grade morphology while supratentorially located GCEs tended to have anaplastic features. GCEs were preferentially located in extraventricular regions. Anaplastic GCEs in adult population seemed to pursue a more aggressive behavior. Gross total resection should still be the main treatment for GCEs.     

Mucin-secreting cellular ependymoma: a light and electron microscopy study

Mucin accumulation in ependymomas is thought to be limited to the myxopapillary variant and represents an important diagnostic feature. Similarly, signet-ring cells in ependymomas have been shown by electron microscopy to represent microrosette instead of mucin secretion. This study describes an infratentorial ependymoma largely composed of mucinous areas and signet-ring cells. The ependymal nature of mucin-secreting cells was confirmed by ultrastructural analysis. This case widens the variable spectrum of ependymal morphology. The value of electron microscopy in differentiating central nervous system neoplasms showing mucous secretion is stressed.     

Myxopapillary ependymoma of the sacrococcygeal region. Report of a case

A case of subcutaneous myxopapillary ependymoma arising in the sacrococcygeal region of a 42-year-old woman is reported. Less than 60 cases of such tumors have so far been described in locations outside the central nervous system. Sacrococcygeal ependymomas are locally aggressive tumors that require a complete and wide surgical excision to prevent recurrences. They tend to metastasize in about 17% of cases.     

Fine-needle aspiration diagnosis of metastatic anaplastic sacrococcygeal ependymoma to the lungs

Ectopic ependymomas are uncommon neoplasms, and most of them occur in the sacrococcygeal area. They usually present as subcutaneous sacral masses. The most common histological subtype is the myxopapillary. We describe a case of anaplastic sacrococcygeal ependymoma metastatic to the lungs diagnosed by fine-needle aspiration biopsy. Diagn Cytopathol 1996;15:228–230. © 1996 Wiley-Liss, Inc.