Ghost cells in pilomatrixoma, craniopharyngioma, and calcifying cystic odontogenic tumor: histological, immunohistochemical, and ultrastructural study.

BACKGROUND: Pilomatrixoma, craniopharyngioma, and calcifying cystic odontogenic tumor are the main entities presenting ghost cells as an important histological feature, in spite their quite different clinical presentation; it seems that they share a common pathway in the formation of these cells. The aim of this study is to examine and compare the characteristics of ghost and other cells that form these lesions. METHODS: Forty-three cases including 21 pilomatrixomas, 14 craniopharyngiomas, and eight calcifying cystic odontogenic tumors were evaluated by immunohistochemistry for cytokeratins, CD138, ß-catenin, D2-40, Glut-1, FAS, CD10 and also by scanning electron microscopy. RESULTS: The CKs, CD138, ß-catenin, Glut-1, FAS, and CD10 were more often expressed by transitional cells of craniopharyngioma and calcifying cystic odontogenic tumor, compared with pilomatrixoma. Basaloid cells of pilomatrixoma showed strong positivity for CD138 and CD10. Differences on expression pattern were identified in transitional and basal cells, as ghost cells were negative for most antibodies used, except by low expression for cytokeratins. By scanning electron microscopy, the morphology of ghost cells were similar in their fibrillar cytoplasm, but their pattern varied from sheets in pilomatrixoma to small clusters in craniopharyngioma and calcifying cystic odontogenic tumor. CONCLUSIONS: Mechanisms involved in formation of ghost cells are unknown, but probably they follow different pathways as protein expression in the basal/transitional cells was not uniform in the three tumors studied.

Mixed pituitary adenoma/craniopharyngioma: clinical, morphological, immunohistochemical and ultrastructural study of a case, review of the literature, and pathogenetic and nosological considerations.

Mixed pituitary adenoma/craniopharyngiomas are very rare tumors. Their pathogenesis is still unclear and it is not known whether they are collision tumors derived from independent stem cells or whether they originate from a single stem cell undergoing divergent differentiation. The latter hypothesis is supported by the close commixture between the two tumor components with transition areas that has been previously described. However, "hybrid" cells with both pituitary adenoma and craniopharyngioma features have never been described. In this paper we report a case of mixed pituitary adenoma/craniopharyngioma observed in a 75-year-old woman presenting with diplopia and slight increase of serum prolactin, who underwent endoscopic endonasal trans-sphenoidal tumor resection. Histologically, the tumor was composed of a typical pituitary silent subtype 2 ACTH cell adenoma admixed with islands of adamantinomatous craniopharyngioma. Electron microscopy showed that, in addition to distinct silent subtype 2 ACTH and craniopharyngioma cells, there were "hybrid" cells, showing characteristics of both pituitary adenoma and craniopharyngioma, consisting of small dense secretory granules, bundles of cytoplasmic filaments, and desmosomes. This ultrastructural finding was also confirmed by the presence of cells showing nuclear p40 expression and chromogranin A immunoreactivity. The close commixture between the two components and the ultrastructural and immunohistochemical findings demonstrate a common histogenesis of the two components and support the classification of the neoplasm as a mixed tumor. The patient completely recovered and, 10 months after surgery, head MR confirmed the complete resection of the lesion.

The cell-cycle kinetics of craniopharyngioma and its clinical significance.

Craniopharyngioma (CP) is a pathologically benign tumor with high incidence of recurrence and poor prognosis. DNA ploidy, S-phase fraction (SPF), and G2 phase/mitosis phase + S phase (G2/M + S) measured by flow cytometry (FCM) have been shown to correlate with cell cycle characteristics and clinical prognosis of other tumors. By use of FCM and terminal deoxynucleotide transferase-mediated dUTP nick end labeling (TUNEL) peroxidase, we compared DNA content, SPF, G2/M + S, necrosis and apoptosis in non-recurrent and recurrent tumor cells of CP from 63 cases including 32 adamantine epitheliomas (AEs) and 31 squamous papillary tumors (SPTs), and the ultrastructure of the CP cell was observed by transmission electron microscopy. Although no obvious differences between DNA content and necrosis and apoptosis rate were observed in subgroups of CPs, SPF and G2/M + S for recurrent tumors were statistically higher than those for recurrence-free tumors, and the recurrence rate of AE tumors is higher than that of SPT. Therefore, CP cells are diploid, and SPF and G2/M + S are related to recurrence of CP.

Collision tumors of the sella: craniopharyngioma and silent pituitary adenoma subtype 3: case report.

Collision tumors of the sella turcica are rare and consist mainly of more than one type of pituitary adenoma, usually a corticotropin- and a prolactin-producing adenoma. The association of a craniopharyngioma and a pituitary adenoma is rare. Herein, we report the first case of an association between craniopharyngioma and silent pituitary adenoma subtype 3. It involved a 12-year-old boy who underwent a frontal craniotomy with surgical removal of a calcified sellar tumor. Histology revealed an adamantinomatous craniopharyngioma; however, by electron microscopy, there was conclusive evidence of adenoma cells showing the ultrastructural features of silent pituitary adenoma subtype 3. Endocrine and neuroimaging as well as detailed immunohistochemical and ultrastructural studies were undertaken. The literature is also reviewed.

Histological findings at the boundary of craniopharyngiomas.

Although a craniopharyngioma is grossly well circumscribed, microscopically the borders are frequently irregular and may be associated with gliosis in the adjacent brain tissue. In the current study, we investigated the histology of the interface between craniopharyngiomas and surrounding normal structures such as the hypothalamus and pituitary gland. Histologically, we classified the findings at the boundary of craniopharyngiomas into three types. In type 1, a relatively thick capsule-like tissue was identified at the boundary between the craniopharyngioma and surrounding normal structure composed of tumor cells and inflammatory changes. In type 2, a craniopharyngioma had a relatively clear cleavage between the surrounding gliosis. In type 3, the boundary had some interdigitation of the tumor in the surrounding gliotic layer adjacent to the craniopharyngioma. In types 1 and 3, surgeons may fail to accomplish complete resection of the tumor. These histological features may result in recurrence of craniopharyngioma even after gross total resection.

Characterization of the levels of expression of retinoic acid receptors, galectin-3, macrophage migration inhibiting factor, and p53 in 51 adamantinomatous craniopharyngiomas.

OBJECT: Craniopharyngiomas are histopathologically defined as benign tumors that can behave very aggressively at the clinical level. They can originate from different types of embryonal epithelial tissue in which correct spatiotemporal regulation has been disrupted at the effector production level. The goal of this study was to determine the efficacy of using selected biological markers to distinguish between recurring and nonrecurring craniopharyngiomas. METHODS: The authors used computer-assisted microscopy to determine quantitatively the immunohistochemical levels of expression of selected markers, including retinoic acid receptors (RARs), as response elements to retinoic acid in a series of 51 adamantinomatous craniopharyngiomas. These tumors may also originate as the result of physiological defects in the apoptosis-mediated elimination of embryological remnants of epithelial tissue. Galectin-3, p53, and the macrophage migration inhibiting factor (MIF) are known to play crucial roles in these processes. The authors quantitatively determined the levels of expression of these substances in this series of 51 craniopharyngiomas. The data show that all craniopharyngiomas were immunoreactive for RARalpha, whereas their immunoreactivity for RARbeta and RARgamma varied dramatically from one case to another. Craniopharyngiomas with low levels of RARbeta and high levels of RARgamma are more likely to recur than those with higher levels of RARbeta and lower levels of RARgamma. Rapidly recurring craniopharyngiomas also show significantly lower levels of expression of galectin-3 and MIF than nonrecurring or slowly recurring cases. Few tumors exhibited p53 immunopositivity. CONCLUSIONS: The data indicate that even in the so-called adamantinomatous group of craniopharyngiomas, several subgroups with different clinical behavior patterns can be identified on the basis of differentiation markers relating mainly to the presence or absence of RARbeta and RARgamma.

Fine structure of ossification in craniopharyngiomas.

Three cases of adamantinomatous craniopharyngiomas were examined by light and electron microscopy and special attention was paid to the formation of ossified tissue. The tumors were composed of neoplastic epithelial cells with keratinized cell nests and fibrous connective tissue. Keratinized cell masses sometimes directly contacted fibrous connective tissue. In these border areas, multipotential mesenchymal cells in the latter may have differentiated into osteoblasts. Ultrastructurally, these osteoblastic mesenchymal cells were surrounded by amorphous ground matrix and collagen fibrils. Membrane-bound vesicles were occasionally seen among the spaces between the collagen fibrils. These vesicles were presumably derived from osteoblastic mesenchymal cells and were morphologically similar to matrix vesicles. Precipitation of hydroxyapatite crystals in these vesicles was considered to be the initial stage of ossification. Further mineralization of adjacent collagen fibrils resulted in the formation of small bone trabeculae. Then apositional growth of ossified tissue occurred in the surrounding keratinized cell masses.

Spontaneous malignant craniopharyngioma in an albino rat.

Craniopharyngioma is a rare neoplasm in the rat, and few cases have been described. These lesions are thought to originate from squamous cell remnants of Rathke's pouch, an evagination of primitive stomatodeum. This neoplasm is usually locally invasive, and neither cranial nor extracranial metastases have been described. A spontaneously occurring malignant, metastasizing craniopharyngioma arising from the neurohypophysis was detected in a 2-year-old male albino rat. The infiltrative growth was observed in the wall of the vessels of the circle of Willis, in the perivascular space of Virchow and Robin, in the submeningeal space near the hypothalamus, through the fissura chorioidea, in the medulla oblongata, and along the optic nerve into the periocular region. Metastases were detected in the thalamus and hippocampus. The diagnosis was made on the basis of microscopic, immunocytochemical and ultrastructural findings.

Ciliated craniopharyngioma indicates histogenetic relationship to Rathke cleft epithelium.

A case of ciliated craniopharyngioma is reported. The patient was a 36-year-old man who suffered from visual disturbance, and he was revealed to have a tumor in the suprasellar region by CT scan. At operation, the tumor was a solid mass accompanied by multiple small cysts. Histologically, the tumor consisted of papillary type of craniopharyngioma in which foci of ciliated columnar epithelial cells were observed. Electron microscopy revealed ciliated epithelium with scattered goblet cells. This uncommon type of craniopharyngioma seems to offer a clue to understand the histogenesis of craniopharyngioma.

Posterior fast craniopharyngioma.

A case is presented of a craniopharyngioma arising in and wholly confined to the posterior fossa in a 23-year-old man. The origin of this unusually located tumour is discussed and comparison made with previously reported ectopic craniopharyngiomas. Most of the cases appeared to be either direct extensions from the suprasellar region or recurrences in locations distant from the original previously treated suprasellar tumours. We found no evidence in this case to relate the tumour to a sellar/suprasellar origin and the craniopharyngioma is believed to have originated in the posterior fossa.

Pharyngeal hypophysis.

Derived from embryologic remnants of Rathke's pouch and its craniopharyngeal duct, the pharyngeal hypophysis has long been considered to be present in all humans. This thesis has been recently challenged, but the weight of investigative evidence still favors the original premise. The pharyngeal hypophysis is just one product of Rathke's pouch. Others are extracranial pituitary tumors, the very rare craniopharyngioma, pharyngeal hypopharyngeal cysts, and cerebrospinal fluid rhinorrhea.

Repercussion of craniopharyngioma on the morphology of the rostral wall of the III ventricle. A combined TEM and SEM study.

Using a combined scanning and electron microscope technique, the repercussion on the rostral wall of the III ventricle in a patient affected with a retrochiasmatic craniopharyngioma with growth in the ventricular direction were analysed. The apical surface of the ependymocytes was found to be free of cilia, although there were numerous microvilli. The most striking finding appreciated with the scanning electron microscope was the presence of bulbous protrusions towards the lumen of the ventricle; these were formed of cells with shapes, sizes and surface characteristics different from the rest of the ependyma, which appeared flattened. The ultrastructural study revealed the presence of large numbers of filaments and junction complexes both in the ependymal and subependymal cells. Additionally, the protruded zones corresponded to areas showing different degrees of cellular disorganization.

Lectin binding and bcl-2 protein expression in craniopharyngiomas.

The maturation process of basal cells in craniopharyngiomas was studied using a panel of lectins, and antibodies against cytokeratin 13 and bcl-2 protein, using oral mucosa for comparison. Seven lectins were employed: peanut (Arachis hypogaea) agglutinin, Dolichos biflorus agglutinin (DBA), Ulex europaeus agglutinin-I (UEA-I), soybean agglutinin, Ricinus communis agglutinin-I, succinyl wheat germ agglutinin, and Pisum sativum agglutinin. DBA and cytokeratin 13 stainings of the suprabasal cells in craniopharyngiomas were comparable to those of the oral mucosa, but not to those of the skin. Staining patterns of the basal cells in the oral mucosa and craniopharyngiomas were generally similar, but UEA-I binding and bcl-2 protein expression in suprabasal cells differed. The difference appeared to be due to a disturbance in the differentiation of the basal cells, because only a small fraction of the basal cells followed a normal maturation process in craniopharyngiomas in comparison to the oral mucosa. The expression of bcl-2 protein may be involved in the pathogenesis of craniopharyngiomas.

Combined TEM and SEM analysis of the rostral wall of the human III ventricle.

A combined morphological study using transmission and scanning electron microscopy was carried out on the central zone of the rostral wall of the III ventricle from a sample taken during the operation of a patient with a retrochiasmatic craniopharyngioma. Under the scanning electron microscope, the apical cell wall of the ependymocytes generally appeared folded and lack in cilia, but with numerous microvilli developed to different extents. The flat surface cells were scarce and were polygonal in shape and limited by 3-7 prominent edges. Ultrastructural analysis revealed the existence of several types of ependymocytes and subependymal epithelial cells arranged in different layers; in both layers the presence of abundant neurofilaments and intercellular junctions was striking.

Origin of craniopharyngioma: an electron microscopic study.

To investigate the possibility that the two subtypes of craniopharyngioma, adamantinous type and squamous papillary type, are tumors arising from different origins, the authors conducted an electron microscopic study in 10 cases of craniopharyngioma. Light microscopic study revealed distinct differences between the two subtypes, but their ultrastructure was fundamentally similar. In this report, the authors propose an explanation of the origin of these subtypes to account for the findings.

Suprasellar xanthomatous Rathke's cleft cyst.

A case of a symptomatic suprasellar Rathke's cleft cyst in a 35-year-old woman is presented. The cyst wall and contents showed large collections of xanthomatous cells. With the exception of a few pituitary hormone-positive cells, immunohistochemical and ultrastructural features of the lining epithelium in this case of Rathke's cleft cyst were indistinguishable from colloid cysts of the third ventricle with similar secondary changes.

Diagnóstico de los tumores endocraneales: tomografía computada, resonancia nuclear magnética, anatomía patológica

Clasificación histológica de los tumores del sistema nervioso central, de acuerdo con la OMS. Nuevos criterios sobre tumores del sistema nervioso en niños. Descripción anatomopatológica de los tumores del sistema nervioso central. Ordenamiento de los tumores endocraneales por frecuencia e incidencia, de acuerdo a edad, sexo y localización. Consideraciones generales sobre el diagnóstico por imágenes de los tumores endocraneales. Estadística de los 765 tumores endocraneales estudiados por tomografía computada, resonancia nuclear magnética, cirugía y anatomía patológica. Descripción de las imágenes de los principales tumores del sistema nervioso central. Biopsia cerebral, guiada por tomografía computada

Diagnóstico de los tumores endocraneales: tomografía computada, resonancia nuclear magnética, anatomía patológica

Clasificación histológica de los tumores del sistema nervioso central, de acuerdo con la OMS. Nuevos criterios sobre tumores del sistema nervioso en niños. Descripción anatomopatológica de los tumores del sistema nervioso central. Ordenamiento de los tumores endocraneales por frecuencia e incidencia, de acuerdo a edad, sexo y localización. Consideraciones generales sobre el diagnóstico por imágenes de los tumores endocraneales. Estadística de los 765 tumores endocraneales estudiados por tomografía computada, resonancia nuclear magnética, cirugía y anatomía patológica. Descripción de las imágenes de los principales tumores del sistema nervioso central. Biopsia cerebral, guiada por tomografía computada

Pituitary adenoma with multiple ciliated cysts: transitional cell tumor?

The case of a prolactin-secreting pituitary tumor with multiple cyst formation is described. Ultrastructurally, the cyst-lining cells were ciliated and closely resembled those of Rathke's cleft cyst but contained secretory granules, and no basal lamina formation was seen between the adenoma cells and the lining cells. Immunohistochemical study revealed that the adenoma cells consisted of both prolactin-secreting cells and growth hormone-secreting cells. The lining cells were immunoreactive with the antiserum to cytokeratin. No S-100 protein-positive cells were seen. The origin of this tumor is discussed.