Perivascular elastic fibers: a diagnostic feature of ependymoma

To assess the diagnostic potential of perivascular elastic fiber detection as an indicator of ependymoma, the authors performed ultrastructural studies on a large series of pediatric brain tumors. Elastic fibers were demonstrated by electron microscopy in 38 of 50 (76%) ependymomas, 2 of 25 (8%) choroid plexus tumors, 0 of 100 (0%) medulloblastomas, and 0 of 100 (0%) astrocytomas. In some poorly differentiated examples, elastic fibers were initially the sole indicator of ependymal differentiation. The authors conclude that the sensitivity and specificity of this feature is sufficient to render demonstration of perivascular elastic fibers a useful diagnostic indicator of ependymoma.     

Ovarian malignant mixed mullerian tumor with primitive neuroectodermal differentiation: case report with review of the literature

Ovarian malignant mixed mullarian tumor (OMMMT) is a rare and aggressive tumor of the female genital tract, occurring mainly in elderly women. Stage of disease is the most important predictor for survival with no prognostic effect, yet, of heterologous elements. Rare case reports described the peculiar presence of primitive neuroectodermal tissue among other heterologous elements in these tumors. Attractive designations, such as teratoid carcinosarcoma, were set by some authors to describe this subset of lesions, where it was considered a primary neuroectodermal tumor capable of multilineage differentiation. We here report a case of OMMMT in an elderly woman with focal primitive neuroectodermal differentiation as the sole heterologous element, and review the controversy on this topic in the literature.     

Stromal cells in hemangioblastoma: neuroectodermal differentiation and morphological similarities to ependymoma

The histogenesis of stromal cells in hemangioblastoma is inconclusive despite a long-term controversy. An immunohistochemical and ultrastructural study was conducted for 17 cases of cerebellar hemangioblastoma. A wide range of immunohistological markers, targeting epithelial, mesenchymal, endothelial and neuroectodermal tissues, was used. In all cases, the microscopic hallmark characterizing hemangioblastomas, that is, lipid-containing stromal cells and a fine capillary network, known as a reticular variant, was noted. Stromal cells showed a variable immunoreactivity for neuroectodermal markers, such as S-100 protein, CD56, CD57, CD99, and neuron-specific enolase. This result, in conjunction with the absence of immunoreactivity for epithelial, mesenchymal, and endothelial markers, likely suggests neuroectodermal differentiation of stromal cells. In three cases, another component, known as a cellular variant, where epithelioid tumor cells were arranged in nests encircled by capillaries and/or in pseudorosette-like structures, was noted. Glial fibrillary acidic protein-immunoreactivity, which was totally absent in cases only showing the reticular pattern, was noted in two of them, suggesting a distinctive sign of glial differentiation in a proportion of hemangioblastomas. Ultrastructurally, microvilli-like projections in intracytoplasmic vacuoles were demonstrated in stromal cells. This result, taken together with the neuroectodermal hypothesis of stromal cells, suggests that hemangioblastomas may occasionally exhibit morphological similarities to ependymomas.     

Squash cytology of tanycytic ependymoma: A report of two cases

Tanycytic ependymoma is a rare variant of ependymoma which has a predilection for the spinal cord. It is a WHO grade II tumour with favourable outcome. Although squash cytology of ependymoma is well described, there is sparse literature available on squash cytomorphology of tanycytic variant. Here we present two cases of squash cytology of tanycytic ependymoma. In the first case the diagnosis of tanycytic ependymoma was considered. However, in the second case a diagnosis of usual ependymoma was offered. Subsequently histopathology confirmed tanycytic nature in both the cases. In this article we discuss the squash cytological features of tanycytic ependymoma along with its differential diagnosis. Diagn. Cytopathol. 2017;45:270–273. © 2016 Wiley Periodicals, Inc.     

Extraspinal ependymoma of the broad ligament

Extraspinal ependymoma is a rare tumor, occurring most commonly in the sacrococcygeal region, and only a small number of cases have been reported to arise in the uterine ligament. Herein is reported a case of extraspinal ependymoma arising in the broad ligament of a 27‐year‐old woman. The lesion was 14 cm in diameter with an intra‐abdominal implant in the omentum. On cut section the tumor was found to be solid, and demonstrated hemorrhaging, necrosis, myxoid foci, and central cystic spaces. Microscopically the tumor was composed of a proliferation of short spindle or polygonal cells arranged in short fascicles or in a solid sheet‐like fashion with occasional perivascular pseudorosettes, together with myxoid areas and variable histological architectures exhibiting cribriform, pseudopapillary, and variable‐sized cystic patterns. On immunohistochemistry most tumor cells were positively reactive to glial fibrillary acidic protein (GFAP), CD99, estrogen receptor, and progesterone receptor. The patient has remained disease‐free for 6 months after the adjuvant chemoradiotherapy. Extraspinal ependymoma should be considered as a differential diagnosis when examining unusual intrapelvic tumors, especially in young female patients. The identification of characteristic histological features such as perivascular pseudorosettes and immunohistochemical expression of GFAP are helpful for confirming the diagnosis.     

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.     

先天性室管膜母细胞瘤尸检分析并文献复习

目的探讨先天性室管膜母细胞瘤的临床及组织病理学特征。方法对1例经尸检诊断的先天性室管膜母细胞瘤的组织病理学、免疫组织化学、超微结构以及DNA倍体情况进行研究,并结合文献复习。结果孕中经B超发现的颅内肿瘤,经尸检确定位于左颞叶近侧脑室后角处,直径约3.5 cm。肿瘤细胞胞核致密浓染,胞质少,密集成团形成具有复层细胞和近腔处活跃核分裂特征的菊形团。免疫组化结果示肿瘤细胞vim entin阳性,GFAP少数阳性。结论室管膜母细胞瘤是一种极少见的神经上皮胚胎性肿瘤,具有特征性的“室管膜母细胞瘤”菊形团结构。肿瘤主要位于幕上,好发于婴幼儿,具有高度侵袭性,预后极差。     

Spinal melanotic ependymoma: A case report and review of literature

We describe an adult female patient diagnosed with spinal melanotic ependymoma. She underwent surgery with the aim of gross total resection, but only subtotal resection was possible. Therefore, the patient was re-evaluated 6 weeks following surgery. Radiotherapy was considered as further treatment. The diagnosis, clinical course, etiology and pathology are discussed on the basis of the current literature.     

Intraoperative diagnosis of tanycytic ependymoma: pitfalls and differential diagnosis

Smear preparations have become increasingly popular in the intraoperative assessment of central nervous system pathology. The cytological features of a histologically proven tanycytic ependymoma are presented with the pitfalls and differential diagnosis. The smear preparation showed a glial neoplasm composed of cells with long, bipolar glial processes and oval to spindle-shaped nuclei resembling those seen in pilocytic astrocytoma smears. The smear characteristics of an ependymoma usually show remarkably uniform round-to-oval nuclei, fluffy glial processes, and a perivascular nuclear-free zone (pseudorosetting). None of these features were present in our case. The accompanying frozen section showed a fascicular spindle-cell tumor that resembled a schwanomma, a commonly reported misinterpretation of the histology of tanycytic ependymomas on frozen sections. Careful attention to the radiological findings, the surgeon's impression, and the intraoperative smear preparation details should allow one to include this uncommon entity in the differential diagnosis of spinal neoplasms.     

Extraspinal ependymoma in the sacrococcygeal region

Summary We describe on a primary, subcutaneous sacrococcygeal ependymoma presenting in a young female patient. Detailed immunohistochemical and electron microscopic examinations were performed. Out of the 40 similar cases reported in literature this is the first in which the determination of DNA content was also used to predict biological behaviour. The tumour proved to be aneuploid with low proliferative capacity in spite of absent histological signs of malignancy. It is suggested that DNA determination may be helpful in establishing prognosis and that it may contribute to a better understanding of the biological behaviour of this tumour.     

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.     

Cytopathologic characteristics and differential diagnostic considerations of osteolytic myxopapillary ependymoma

Myxopapillary ependymoma (MPE) is a rare variant of conventional ependymoma found predominantly in the sacrococcygeal region in young adults and characterized by its distinct epithelial and stromal components (WHO grade I designation). MPE with extensive osteolysis is extremely uncommon and only up to 40 cases have been documented. A case is presented here in which imprint smears of a sacral tumor in an 18‐year‐old man revealed complex papillary structures, small loose clusters, or cord‐like structures of bland tumor cells embedded in a myxoid or mucinous background. The tumor cells possessed uniformly round nuclei with a smooth nuclear outline, fine granular chromatin, and small nucleoli. Slender cytoplasmic fibrillary processes and occasional intracytoplasmic vacuoles were observed. A cytologic diagnosis of a MPE was suggested and histochemical and immunohistochemical studies were conducted on formalin‐fixed, paraffin‐embedded material. Immunohistochemically, the tumor cells showed diffuse and strong membranous and cytoplasmic staining for cytokeratin AE1/AE3, glial fibrillary protein, and S‐100 protein, but negative for epithelial membrane antigen, pan‐neuroendocrine markers (i.e., NSE, chromogranin A, synaptophysin), or brachyury. The proliferative index with MIB‐1 was around 10%. The diagnosis of osteolytic MPE was confirmed based on cytopathologic, histopathological, immunohistochemical results, radiologic findings, and the location of the tumor. We demonstrated here the cytopathological features of osteolytic MPE with emphasis on differential diagnostic considerations. Diagn. Cytopathol. 2014;42:778–783. © 2013 Wiley Periodicals, Inc.     

Multiple chromosomal monosomies are characteristic of giant cell ependymoma

Giant cell ependymoma, a rare ependymoma subtype, was recently recognized as a separate diagnostic entity with variations both in malignant potential and course of disease. We analyzed the first supratentorial giant cell ependymoma using G-band karyotyping, DNA ploidy analysis, and array comparative genomic hybridization. The tumor was hypodiploid, and the karyotype showed multiple monosomies. This novel cytogenetic pattern seems specific for giant cell ependymoma as the only previous cytogenetic analysis of a giant cell ependymoma found similar monosomies. We were also able to analyze cytogenetically the subsequent recurrent tumor, phenotypically an anaplastic ependymoma, allowing a first insight into the genetic events involved in disease progression.     

Gliosarcoma arising from an anaplastic ependymoma: a case report of a rare entity

We report the first case of a gliosarcoma arising from an anaplastic ependymoma and the second case of gliosarcoma arising from any type of ependymal neoplasm. The patient was a 48-year-old woman with a solid and cystic, peripherally enhancing, 7-cm right frontal mass lesion. Histologically, the lesion displayed characteristics of anaplastic ependymoma (grade III, World Health Organization scale). The tumor recurred despite multiple cycles of postoperative radiation and chemotherapy. After the fourth recurrence, the tumor displayed a biphasic pattern of differentiation. The first pattern was similar to the original anaplastic ependymoma, whereas there was a second new sarcomatous pattern resembling fibrosarcoma that was admixed with and overrunning the ependymal component. The spectrum of gliosarcoma is therefore expanded to include not only astrocytic and oligodendroglial components but ependymal components as well.     

伸展细胞型室管膜瘤的病理学观察

目的 探讨伸展细胞型室管膜瘤的临床病理特点、诊断及鉴别诊断。方法 对6例伸展细胞型室管膜瘤进行光镜、免疫组化、特殊染色、电镜观察并结合文献进行分析。结果 肿瘤主要由长梭形细胞构成,呈束状交错状、车辐状排列,可见围绕血管分布,形成假菊形团。瘤细胞呈单极或双极突起细长,分化好,核分裂象罕见,未见坏死。免疫组化标记瘤细胞vimentin强阳性,GFAP、S-100蛋白、EMA阳性,Syn和HHF35阴性。超微结构观察见较多的中间细丝和发育好的的桥粒,以及细胞间腔隙内有微绒毛。结论 伸展细胞型室管膜瘤起源于脑室附近伸展细胞,是罕见的室管膜瘤的一个亚型,在诊断上往往易与其它梭形细胞为主的神经上皮肿瘤相混,病理诊断依赖于组织学、免疫组化、特殊染色和电镜观察。免疫组化和特殊染色在鉴别诊断中有重要价值。     

Ectopic cervical anaplastic ependymoma

Ependymomas generally arise in the central nervous system (CNS), although rare primary extraneural ependymomas have been observed. Reported herein for the first time is the case of a patient with primary ectopic cervical anaplastic ependymoma. The tumor was found in the right neck root region of a 35-year-old man. No additional tumor was found in the CNS or in other parts of the body. The patient received surgery and post-surgical local radiotherapy. Microscopically, the tumor consisted of round to oval cells with fine chromatin, distinct nucleoli, moderate nuclear atypia and numerous mitoses (>25/10 high-power fields) in a densely cellular growth pattern with characteristic fibrillary cytoplasm and formation of perivascular pseudorosettes. By immunohistochemistry, the tumor cells were positive for glial fibrillary acidic protein, epithelial membrane antigen (EMA), vimentin and S-100 protein. EMA staining showed a membranous as well as a paranuclear pattern of immunoreactivity. Electron microscopic studies revealed that tumor cells form micro rosettes, into which microvilli and cilia projected. The diagnosis was World Health Organization grade III anaplastic ependymoma. There is no evidence of local tumor recurrence or distant metastasis after 30 months follow up. The present case adds yet another unique example to the already diverse spectrum of head and neck neoplasms encountered in surgical pathology.     

伸长细胞型室管膜瘤2例报道及文献复习

目的探讨伸长细胞型室管膜瘤的病理形态学特征。方法复习2例伸长细胞型室管膜瘤的临床病理资料,对手术切除的肿瘤组织,常规石蜡切片,HE染色,光镜观察,同时进行免疫组织化学标记GFAP、EMA、S-100蛋白、CKpan、Syn、CD34。结果例1位于腰2～3椎管内终丝,临床上主要表现出脊髓压迫症状,如运动及感觉障碍;例2发生于侧脑室,主要表现为头痛、呕吐、视物模糊。病理组织学上肿瘤富于细胞,排列成束状、交织状,细胞胞突细长双极,核异型性小,少数肿瘤细胞围绕血管周围形成室管膜瘤的无核区结构。免疫组化显示肿瘤细胞表达GFAP、EMA、CD99,而S-100蛋白阴性。结论伸长细胞型室管膜瘤是室管膜瘤的一种罕见亚型,病理诊断时尤其应注意与椎管内的神经鞘瘤和星形细胞瘤鉴别。     

Myxopapillary ependymoma: cytomorphologic characteristics and differential diagnosis

Myxopapillary ependymoma (ME) is a rare tumor with a predilection for sacrococcygeal area of adults. We present the cytomorphology of one such case in a 21-yr-old man, diagnosed by fine-needle aspiration (FNA). The tumor disclosed biphasic morphology with nests and aggregates of epithelioid malignant cells as well as branching cords of myxohyaline material. Most noticeable was the presence of distinct hyaline globules surrounded by neoplastic cells. The differential diagnosis of ME includes chordoma, adenoid cystic carcinoma, mucinous adenocarcinoma, and germ cell tumor. An accurate preoperative diagnosis of ME on FNA can be achieved based on its distinctive cytomorphologic features.