A Case Report of a Choroid Plexus Carcinoma Spontaneously Occurring in the Right Lateral Ventricle of a 14-Week-Old, Female Donryu Rat

We encountered a brain tumor arising in the right lateral ventricle of a 14-week-old, female Donryu rat and investigated its histological and immunohistochemical characteristics. Macroscopically, the tumor appeared as a grayish mass with a size of 10 mm in diameter, present in front of the right hemicerebrum and well circumscribed on the cut surface. Histological examination revealed the tumor to be a hypercellular mass occupying the front part of the right lateral ventricle and expanding into the area in front of the hemicerebrum, continuing to the ependymal area at its edge. The tumor was constituted by columnar- or pleomorphic-shaped, highly atypical cells of epithelial origin surrounding fibrovascular cores as single or multiple cell layers. Growth was papillary with high proliferating activity. Immunohistochemically, the tumor cells proved positive for cytokeratin but negative for vimentin, S100 protein or glial fibrillary acidic protein, a profile characteristic for the epithelial cells of the choroid plexus, whereas the ependymal cells were found to be positive for all 4 items. In conclusion, the present tumor was diagnosed as a rat choroid plexus carcinoma, only the third such case to be reported in the world literature, with particular features.

Jugular foramen chordoid meningioma

Chordoid meningioma (CM) is a rare histological variant of meningioma and is classified as an atypical meningioma on pattern alone. Herein is described the first case of CM occurring in the jugular foramen. The patient was a 45-year-old woman with a 2 year history of progressive right hearing loss. Magnetic resonance imaging (MRI) demonstrated a large, dumbbell-shaped, homogenously gadolinium-enhanced mass in the right jugular foramen, extending medially to the cerebellopontine angle and caudally into the upper carotid space. Angiographic findings supported a diagnosis of schwannoma. Intraoperatively, the tumor appeared to involve the right glossopharyngeal nerve completely and the vagus nerve incompletely, and was incompletely resected. Microscopically, the tumor consisted predominantly of cords and nests of medium-sized cells with bland cytological features, surrounded by a pale basophilic mucin. Immunohistochemically, the tumor cells demonstrated reactivity for epithelial membrane antigen (membranous) and vimentin, with negative staining for S-100 protein, cytokeratin, CD34, glial fibrillary acidic protein (GFAP), synaptophysin, and chromogranin A. Based on the chordoid histology, an organoid lobular arrangement of the tumor cells, and the location of the tumor (jugular foramen), the differential diagnosis included not only a chordoma but also a paraganglioma (glomus jugulare tumor). Histological identification of typical meningotheliomatous areas, plus selective immunohistochemical panel, is important to establish the correct diagnosis.

Origin of chordoid glioma of the third ventricle

CONTEXT

Chordoid glioma is a relatively recently described unique glial neoplasm that has been formally codified by the World Health Organization in Pathology and Genetics of Tumours of the Nervous System, in which it is included along with astroblastoma and gliomatosis cerebri under the rubric "Tumors of Uncertain Origin." Many examples of chordoid glioma come to clinical attention only at a relatively large size and occupy a large portion of the third ventricle. Accordingly, the anatomic origin of chordoid glioma has been unclear and debated.

OBJECTIVE

To examine the regional anatomic origin of chordoid glioma.

DATA SOURCES

The clinical, imaging, histologic, immunophenotypic, and ultrastructural data in previously published case series and individual case reports of chordoid glioma were reviewed in conjunction with the study of a new case of chordoid glioma that presented at a relatively small size, thereby facilitating neuroanatomic localization.

CONCLUSIONS

Chordoid glioma exhibits features of specialized ependymal differentiation on ultrastructural examination, and all examples reported in the literature to date have displayed a highly stereotypical suprasellar anatomic localization and an ovoid shape, as seen on neuroimaging studies and gross anatomy. Neuroanatomic, radiologic, and clinical evidence supports an anatomic origin for chordoid glioma from the vicinity of the lamina terminalis.

Choroid plexus carcinoma presented with spinal dysfunction caused by a drop metastasis: a case report

A 2-year-old girl demonstrating gait disturbance and dysuria was evaluated and showed two large remote tumors at the left lateral ventricle and lower spinal canal. Pathological analysis demonstrated both of the tumors to be choroid plexus carcinoma (CPC) with high MIB-1 labeling index. The enhanced mitotic propensity would have contributed to an early stage of drop metastasis from the primary site to the sacral sac and following accelerated formation of a longitudinal tumor, which had grown in the subarachnoid space conforming to the spinal canal and finally caused the presenting symptoms of spinal dysfunction. This report shows that CPC can develop exophytically in the subarachnoid space as well as in the ventricle simultaneously before appearance of clinical symptoms and confirms the importance of extensive neuroimaging in its evaluation.

Pathological and immunohistochemical studies of choroid plexus carcinoma of the dog

Choroid plexus carcinomas in four dogs (three male, one female) aged small middle 2.5 to 10 years, were examined by light microscopy and immunohistochemistry. The dogs showed progressive neurological signs including ataxia, seizures, vestibular disease and cranial nerve deficits, lasting for several months in some cases. Primary tumours were localized in the lateral (one case), third (one case), and fourth (two cases) ventricles. Hydrocephalus was evident at post-mortem examination in one case. In two cases the neoplastic cells closely resembled the structure of normal choroid plexus, with a distinct papillary pattern, composed of well-differentiated columnar epithelium. In the other two cases, cellular pleomorphism, nuclear atypia, increased mitotic activity and necrosis were observed. In all cases, dissemination of neoplastic cell clusters was detected within the subarachnoid space or the ventricular cavity. Immunohistochemical examination showed a multifocal labelling pattern for pankeratin and cytokeratin AE1 and diffuse vimentin positivity in poorly differentiated tumours. Well-differentiated choroid plexus carcinomas showed multifocal immunoreactivity for cytokeratin AE3, multifocal to diffuse immunoreactivity for vimentin and occasional positivity for carcinoembryonic antigen. Epithelial membrane antigen, Ber EP4 and S-100 were negative in all cases. Glial fibrillary acidic protein labelling occurred only in a single, poorly differentiated tumour. Occasional reactions for proliferating cell nuclear antigen and MIB-1 were seen in two cases. It was concluded that at least two morphological and possibly phenotypic subtypes (well-differentiated and anaplastic) of choroid plexus carcinoma of the dog could be identified.

Evaluation of proliferative index and cell cycle protein expression in choroid plexus tumors in children

Choroid plexus tumors are papillary neoplasms originating from the epithelium of the choroid plexus within the cerebral ventricles. They may be highly proliferative tumors, but detailed studies confirming their proliferative potential are lacking. Accordingly, we performed a clinicopathological correlation study of neoplasms arising from the choroid plexus in children using immunohistochemistry to characterize both their proliferative potential and their degree of cell cycle dysregulation when compared to non-neoplastic choroid epithelium. Twelve children with choroid plexus papillomas (CPPs) and 11 with choroid plexus carcinomas (CPCs) were identified from the time period 1982-1997. The outcome and survival of these children following treatment was determined from the medical record. Immunohistochemical studies were performed on CPPs and CPCs in this patient population and on non-neoplastic choroid epithelium using antibodies to MIB-1, p53, cyclin E, retinoblastoma protein (pRB), p107, and E2F-1. In 5 children with CPCs, tumor tissue was available for immunohistochemistry at a second surgery after cycles of chemotherapy had been given. The mean survival for patients with CPPs was 8.5 years, and with CPCs 5.2 years with a minimum follow-up of 4 years for the group. The expression of cell cycle markers and MIB-1 was greater in CPCs than in CPPs or normal choroid plexus. The expression of MIB-1, p53, pRB, and E2F-1 was significantly lower in patients with CPCs after chemotherapy than before. The MIB-1 labeling index for CPC patients who are alive and well after treatments was 15.19+/-3.2 compared to 22.63+/-3.04 for patients who have died from their disease (P<0.05). We conclude that CPCs in children are characterized by a higher MIB-1 labeling index and greater cell cycle dysregulation than are CPPs. Chemotherapy may work in part on CPCs to decrease their proliferative potential and expression of cell cycle regulatory proteins.

Choroid plexus papilloma diagnosed by crush cytology

In a 32-yr-old man, an infratentorial cystic lesion with a mural nodule was interpreted to be either a hemangioblastoma or a cystic astrocytoma on CT scan. Intraoperative crush cytology revealed it to be a choroid plexus papilloma (CPP). The utility of crush cytology in the rapid diagnosis of central nervous system (CNS) tumors and the differential diagnosis of CNS papillary lesions are highlighted in this report.

Chordoid glioma of the third ventricle: an ultrastructural study of three cases with a histogenetic hypothesis

Chordoid glioma is a rare neoplasm occurring in the third ventricle and, as the name implies, having a chordoid appearance. It is currently considered a glial neoplasm of uncertain histogenesis with distinct clinicopathologic features. We report three cases of chordoid glioma with a focus on the ultrastructural appearance. The patients were two men and one woman aged, respectively, 34, 40, and 43 years. Immunohistochemically, all tumors showed strong and diffuse reactivity for glial fibrillary acidic protein and vimentin, whereas immunoreactivity for epithelial membrane antigen and cytokeratin was focal. Ultrastructurally, they showed features of ependymal differentiation for the presence of an apical pole with microvilli and a basal pole characterized, as in normal ependyma, by many hemidesmosomelike structures connecting cell membranes to the underlying basal lamina. Constant features were a submicroscopic cell body zonation (i.e., perinuclear, intermediate, subapical, and apical regions) and the presence of secretory granules. These findings were similar to those described for the secretory ependymal cells of the subcommissural organ, a small structure located in a dorsocaudal region of the third ventricle that undergoes regression after birth in humans. Our observations suggest that chordoid glioma may represent a subtype of ependymoma whose cells resemble the highly specialized ependyma of the subcommissural organ.

Choroid plexus papilloma with osseous and adipose metaplasia

Rare cases of osseous and chondroid metaplasia in choroid plexus papillomas have been described. We report a case of left lateral ventricular choroid plexus papilloma presenting in a 25-year-old man. The tumor demonstrates prominent calcification with associated osseous metaplasia and a region of adipose metaplasia, which has not been previously described in these tumors. There is no evidence of mucin in the papilloma on mucicarmine and alcian blue stains. A MIB-1 labeling index (marker of cell proliferation) of 0.1% was noted. P53 immunoreactivity was not observed in the papilloma. Ann Diagn Pathol 5:43-47, 2001.

Chordoid glioma: a novel tumor of the third ventricle

Chordoid glioma of the third ventricle is a recently characterized primary neoplasm of the central nervous system. We present a case and discuss the pathologic and radiologic features. We are aware of only 16 other cases documented in the world literature. This radiologic-pathologic correlation alerts pathologists and radiologists to recognize chordoid glioma as a distinct clinicopathologic entity restricted to the third ventricular area of adult patients.

Primary choroid plexus carcinoma producing carbohydrate antigen 19-9

An autopsy case of primary choroid plexus adenocarcinoma arising in a 40-year-old female, who was associated with a high serum level of a carbohydrate antigen 19-9 (CA19-9), is herein presented. After a subtotal removal of a tumor in the left lateral ventricle, the serum level of CA19-9 decreased rapidly, and immunohistochemical examinations of tumor tissue specimens obtained at surgery revealed intense reactivity for CA19-9. The present case may be the first example in which a primary choroid plexus carcinoma was shown to produce CA19-9.

Choroid plexus papilloma: a clinicopathological study of 23 cases

BACKGROUND

Choroid plexus papillomas (CPPs) are rare, accounting for less than 1% of all intracranial tumors in adults. However, they are relatively more common in childhood and constitute 1.5 to 4% of intracranial tumors.

DESCRIPTION

They are most often located in the lateral ventricle, followed by the fourth and third ventricles and, rarely, in the cerebellopontine angle. The radiological appearance of a CPP as a cyst with a mural nodule is a curiosity. Bone formation is rare in CPPs and only 6 cases have been described in the literature. Neuromelanin production is also extremely rare and only 2 cases have been reported to date.

CONCLUSION

In the present communication, 23 cases of CPP are analyzed and rare clinical, pathological, and radiological features are described.

Choroid plexus epithelium (normal and neoplastic) expresses synaptophysin. A potentially useful aid in differentiating carcinoma of the choroid plexus from metastatic papillary carcinomas

As an incidental finding in paraffin sections of brain tissue used as positive controls for synaptophysin immunostain, the cytoplasm of choroid plexus epithelium present was found to stain strongly positively for this substance. This was subsequently found to be the case in normal choroid plexuses in autopsy material from infancy to old age, as well as in epithelial cells of papillomas and carcinomas of the choroid plexus. The latter findings may prove useful in differentiating choroid plexus carcinomas from metastatic papillary carcinomas of extracerebral origin with the exception of neuroendocrine carcinomas of various sites that are usually positive for synaptophysin.

Immunocytochemical detection of insulin-like growth factor II (IGF-II) in choroid plexus papilloma: a possible marker for differential diagnosis

BACKGROUND

Insulin-like growth factor II (IGF-II) has been detected in the choroid plexus of animals by means of immunohistochemistry and in situ hybridization, and this factor is thought to play an important role in the central nervous system (CNS). Little is known, however, about the presence and localization of this substance in the choroid plexus and in choroid plexus papilloma in humans.

MATERIALS AND METHODS

5 normal choroid plexus and 10 choroid plexus papillomas were examined for IGF-II by immunocytochemistry. IGF-II was not detected in normal human choroid plexus, whereas it was found in choroid plexus papilloma. Furthermore, to assess the possibility that IGF-II could serve as an immunohistological marker of choroid plexus papilloma, we used the same technique to examine paraffin-embedded samples from various kinds of brain tumors.

RESULTS AND CONCLUSION

Our results suggest that IGF-II may be a useful marker for choroid plexus papilloma in differential diagnosis.

Intraventricular perineurioma: case report

OBJECTIVE AND IMPORTANCE

Perineurioma, a rare benign nerve sheath neoplasm occurring in either an intraneural or soft tissue form, has never been reported to arise in the central nervous system.

CLINICAL PRESENTATION

We describe the clinical, radiological, and pathological features of a perineurioma arising in the choroid plexus of the third ventricle in a 65-year-old woman and causing obstructive hydrocephalus.

INTERVENTION

The lesion, apparently unassociated with a nerve, was gross totally resected by frontal craniotomy using a left-sided transcallosal approach. Short-term follow-up showed no evidence of recurrence.

CONCLUSION

Perineurioma of the variety found in soft tissue may occur in the central nervous system, wherein it shows the typical light microscopic, immunohistochemical (epithelial membrane antigen- and Collagen IV-positive, S-100 protein-negative), and ultrastructural (pinocytotic vesicles, discontinuous basement membrane) features.

Pathology of choroid plexus papillomas: a review

Choroid plexus papillomas (CPPs) are rare, usually slow growing neoplasms. Their biological behaviour cannot be predicted in an individual case. Furthermore, the neuropathological diagnosis of these neoplasms is occasionally difficult because light and electron microscopical and immunohistochemical features may overlap with those of other neoplasms localising in the choroid plexus. The aim of this paper is to review the pathological literature (light and electron microscopy (EM) and immunocytochemistry), to provide guidance on current diagnostic tools and criteria and address the identification of 'atypical' CPPs, e.g. those CPPs with histological features indicative of aggressive behaviour, in an attempt to help bridge the diagnostic gap between benign CPPs on the one hand and choroid plexus carcinomas (CPCs) on the other.

Spontaneous choroid plexus carcinoma in an albino rat

Neoplasms of the choroid plexus are very rare in the rat, and few cases have been described. We report on a spontaneously occurring choroid plexus carcinoma arising from the fourth ventricle in a 2-year-old female albino rat. The infiltrative growth was observed in the adjacent brain parenchyma, in the wall of the vessels of the circle of Willis, in the perivascular space of VIRCHOW and ROBIN and in the leptomeninges. Immunohistochemical investigations demonstrated positive staining for cytokeratin (Lu-5) indicating that choroid plexus tumors in the rat express epithelial differentiation. The diagnosis was made on the basis of microscopical and immunohistochemical findings.

MIB-1 immunoreactivity reveals different labelling in low-grade and in malignant epithelial neoplasms of the choroid plexus

MIB-1 immunohistochemistry was carried out on a retrospective biopsy series of epithelial choroid plexus neoplasms in order to assess the proliferation rate of tumour cells. The material included 14 cases of papilloma (WHO grade I) and five cases of carcinoma (WHO grade III). There was one recurrent tumour in the papilloma group, while three patients with carcinoma experienced recurrence. Choroid plexus obtained at autopsy from paediatric and adult patients with unrelated diseases served as control. The average MIB-1 labelling index of choroid plexus papillomas was 3.7%, while that of carcinomas was 14%, and that of normal choroid plexus was 0.02% to 0.06%. The age and sex of the patients as well as the tumour localization were not found to influence MIB-1 reactivity. The labelling index of recurrent lesions was not significantly different from that of the corresponding primary tumours. High MIB-1 labelling indices were associated with less favourable post-operative outcome in choroid plexus carcinomas and in one papilloma with atypical histology. However, most tumours with atypical histological features did not exhibit distinctive MIB-1 labelling indices. Analysis of growth fraction by MIB-1 immunohistochemistry may prove a useful ancillary method for assessing the malignant potential of choroid plexus neoplasms.

Immunohistochemical localization of the glucose transporter GLUT1 in choroid plexus papillomas

Normal chroid plexus tissue and five choroid plexus papillomas were examined with antibody specific for the glucose transporter GLUT1, one isoform of facilitated-diffusion glucose transporters, using the avidin-biotin-peroxidase complex (ABC) technique. GLUT1 in normal choroid plexus was localized at the basolateral plasma membrane of almost all epithelial cells. In three of five tumors, GLUT1 immunoreactivity was observed. A positive reaction was demonstrated at the plasma membrane of tumor cells. The number of GLUT1-positive cells was, however, much smaller than that of the normal choroid plexus. Our results suggest that GLUT1 expression in the choroid plexus is restrained during the course of transformation and that choroid plexus papilloma is composed of various differentiation tumor cells.

The choroid plexus carcinomas of childhood: histopathology, immunocytochemistry and clinicopathological correlations

Anaplastic choroid plexus carcinoma is a tumour with a predilection for the posterior fossa of infants and can be difficult to distinguish histologically from medulloblastoma without the aid of immunocytochemistry using a panel of antibodies. Of a series of 17 choroid plexus carcinomas (five of which were classed as moderately differentiated and 12 as anaplastic) 17 expressed antigens to transthyretin, transferrin and cathepsin and 16 expressed carbonic anhydrase II. Eleven expressed at least one epithelial marker (cytokeratin or epithelial membrane antigen). In contrast, none of six medulloblastomas expressed epithelial markers, transrythetin, carbonic anhydrase II or transferrin, though three were positive with antibodies to cathepsin.

Choroid plexus tumours--an immunohistochemical analysis with review of literature

Immunohistochemical analysis of 9 choroid plexus papillomas (CPPs) and 3 choroid plexus carcinomas (CPCs) using a panel of antibodies against glial fibrillary acidic protein (GFAP), cytokeratin (CK), epithelial membrane antigen (EMA), S-100 protein, vimentin (vim), and neuron specific enolase (NSE) is presented. Focal positivity was observed for GFAP in 11, vimentin in 7, cytokeratin in 2 and EMA in 3 cases. Diffuse and intense immunoreactivity for S-100 protein was seen in all papillomas, however, unreactive areas were noted in carcinomas. All cases exhibited focal to diffuse NSE positivity. Location and type of the tumour and age of the patient did not influence the staining pattern except for predominant S-100 positivity in papillomas. The significance of these findings is discussed in relation to the differential diagnosis or immunoreactivity patterns of these tumours.

Epithelial differentiation in gliomas, meningiomas and choroid plexus papillomas

The immunohistological findings using antibodies to different intermediate filaments (glial fibrillary acidic protein, vimentin and two types of cytokeratin) and epithelial membrane antigen are described in 89 gliomas, 19 meningiomas and 8 choroid plexus papillomas (CPPs) from adult patients. All the patients had total or subtotal surgical excision of their tumours with clinical follow up for between 3 and 7 years. The immunohistological results were correlated with the histological features and patient survival. Tumours other than low grade astrocytomas, oligodendrogliomas and anaplastic ependymomas expressed one or more epithelial markers. This immunohistological evidence of epithelial differentiation in the absence of histological epithelial features in gliomas confirms that the two are not necessarily correlated. It is concluded that the expression of epithelial markers in some intradural tumours may reflect aberrant differentiation related to the degree of anaplasia in poorly differentiated astrocytomas and glioblastomas. All the patients with anaplastic epithelial marker-positive gliomas died within 1 year, whereas only 68% of patients with marker-negative tumours died within the follow-up period. In ependymomas and meningiomas, the expression of epithelial markers may reflect their histogenesis, while in malignant CPPs such expression could denote either their aberrant differentiation or histogenetic derivation.

Transthyretin immunoreactivity in choroid plexus neoplasms and brain metastases

Although choroid plexus papillomas (CPP) and primary choroid plexus carcinomas (CPC) are rare neoplasms of the central nervous system, they have been the subject of a number of immunohistochemical studies. To date, no unique or specific marker for these neoplasms has been found, however. Normal choroid plexus is a major site of transthyretin (TTR) synthesis, and recently this protein has been proposed as a possible specific marker of choroid plexus differentiation in tumors. In this study, we performed immunohistochemistry for TTR on 13 choroid plexus tumors (six CPP and seven CPC) and on 23 carcinomas metastatic to the brain, four of which had a papillary architecture. We also included four ovarian teratomas that contained choroid plexus elements. Two of the CPP had diffuse staining for TTR, while the four others stained only focally. Five of the CPC stained only focally and less intensely than the control, while one case was negative. Only one CPC stained as strongly and diffusely as normal choroid plexus. Two of the papillary and six of the nonpapillary metastases had focal staining similar to that seen in the five focally positive CPC. The choroid plexus elements of the ovarian teratomas stained as strongly as the positive control. These findings indicate that TTR immunoreactivity is not restricted to primary choroid plexus tumors. Furthermore, most choroid plexus carcinomas stain only weakly or not at all. This limits the usefulness of TTR immunohistochemistry in the diagnosis of primary choroid plexus neoplasms and in the distinction of CPC from metastatic carcinoma.