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The Continuing Value of Ultrastructural Observation in Central Nervous System Neoplasms in Children.

Kim NR, Park SH - J Pathol Transl Med (2015)

Bottom Line: Diagnostic dilemmas with small specimens from CNS neoplasms are often the result of multifactorial etiologies such as frozen or fixation artifact, biopsy size, or lack of knowledge about rare or unfamiliar entities.Nowadays, pathologic diagnosis of CNS neoplasms is achieved through intraoperative cytology, light microscopy, immunohistochemistry, and molecular cytogenetic results.Here, we reviewed the distinguishing ultrastructural features of pediatric CNS neoplasms and emphasize the continuing value of EM in the diagnosis of CNS neoplasms.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Gachon University Gil Medical Center, Incheon, Korea.

ABSTRACT
Central nervous system (CNS) neoplasms are the second most common childhood malignancy after leukemia and the most common solid organ neoplasm in children. Diagnostic dilemmas with small specimens from CNS neoplasms are often the result of multifactorial etiologies such as frozen or fixation artifact, biopsy size, or lack of knowledge about rare or unfamiliar entities. Since the late 1950s, ultrastructural examination has been used in the diagnosis of CNS neoplasms, though it has largely been replaced by immunohistochemical and molecular cytogenetic studies. Nowadays, pathologic diagnosis of CNS neoplasms is achieved through intraoperative cytology, light microscopy, immunohistochemistry, and molecular cytogenetic results. However, the utility of electron microscopy (EM) in the final diagnosis of CNS neoplasms and investigation of its pathogenetic origin remains critical. Here, we reviewed the distinguishing ultrastructural features of pediatric CNS neoplasms and emphasize the continuing value of EM in the diagnosis of CNS neoplasms.

No MeSH data available.


Related in: MedlinePlus

(A) Meningioma shows closely apposed oval- to spindle-shaped tumor cells having interdigitating cell processes lined by well-formed desmosomes (×8,000). Inset indicates tonofibrils attached to the desmosomal plaques (×30,000). (B) Schwannoma shows abundant reduplicated continuous basal lamina surrounding the interdigitating cell processes (×3,500). Note the extracellular long-spacing collagen (arrow) and high power view of reduplicated basal lamina (inset, ×6,500). (C) Ependymoma reveals spindle cells with numerous cytoplasmic processes filled with bundles of intermediate filaments (×4,000). Inset shows well-formed zonula occludens with surface microvilli (×15,000). (D) Pilomyxoid astrocytoma shows bipolar cells with surface microvilli and cilia in the electron-lucent extracellular space (×9,000). Note some intracellular microlumen. (E) Astrocytoma shows loosely scattered round to oval cells having numerous long cytoplasmic processes filled with bundles of glial filaments and scarce other organelles (×2,500). (F) Glioblastoma shows many pleomorphic spindle and oval cells with numerous cytoplasmic processes containing bundles of intermediate filaments with surface microvilli-like differentiation (×2,500). (G) Medulloblastoma shows that loosely arranged oval-shaped tumor cells project cytoplasmic processes forming rosettes filled with glial filaments and dense core granules indicating neuroglial differentiation (×9,000). (H) Neuroblastoma reveals that closely packed polygonal to spherical tumor cells have numerous, thin, electron-lucent cell processes forming an interlacing meshwork between groups of cell bodies (×9,000). Inset shows longitudinally-oriented 20 nm microtubules (white arrow) and dense core granules (black arrow, ×15,000). (I) Primitive neuroectodermal tumor reveals round to closely apposed oval-shaped tumor cells with abundant cytoplasmic processes containing sparse organelles including glycogen particles, mitochondria, and some microtubules (×8,000).(J) Atypical teratoid and rhabdoid tumor reveals paranuclear aggregates of intermediate filaments (arrow) compressing the heterochromatic nuclei (×15,000). (K) Oligodendroglioma presents tumor cells with uniform round nuclei and sparse cytoplasmic organelles as well as some irregularly shaped cell processes (arrow) containing occasional globoid collections of intermediate filaments (×3,500). (L) Neurocytoma reveals round tumor cells with a moderate amount of cytoplasm and numerous long thin cell processes containing microtubules, few electron dense core granules and secretory vesicles (arrow), and glial intermediate filaments (×8,000). (M) Dysembryoplastic neuroepithelial tumor reveals oligodendroglial-like cells with elongated bulbous cell processes forming a neuropil-like structure filled with intermediate filaments in electron-lucent mucoid extracellular spaces (×7,000).(N) Papillary tumor of the pineal region reveals polygonal-shaped tumor cells having short-villous cell surfaces and cytoplasm having abundant rough endoplasmic reticulums with distended cisternae and vacuoles (×3,500). (O) Chordoid glioma of the third ventricle reveals tumor cells with cytoplasmic processes filled with intermediate glial filaments and surrounded by basal lamina (×7,000). Note the numerous surface microvilli (arrow). (P) Choroid plexus papilloma shows ovoid to polygonal tumor cells arranged in glandular patterns joined by well-formed junctional complexes and a continuous basal lamina (arrow) surrounding these glandular structures (×1,500). Note the apical portion of tumor cells lined by numerous microvilli and cilia composed of 9+2 microtubules.
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f1-jptm-2015-09-19: (A) Meningioma shows closely apposed oval- to spindle-shaped tumor cells having interdigitating cell processes lined by well-formed desmosomes (×8,000). Inset indicates tonofibrils attached to the desmosomal plaques (×30,000). (B) Schwannoma shows abundant reduplicated continuous basal lamina surrounding the interdigitating cell processes (×3,500). Note the extracellular long-spacing collagen (arrow) and high power view of reduplicated basal lamina (inset, ×6,500). (C) Ependymoma reveals spindle cells with numerous cytoplasmic processes filled with bundles of intermediate filaments (×4,000). Inset shows well-formed zonula occludens with surface microvilli (×15,000). (D) Pilomyxoid astrocytoma shows bipolar cells with surface microvilli and cilia in the electron-lucent extracellular space (×9,000). Note some intracellular microlumen. (E) Astrocytoma shows loosely scattered round to oval cells having numerous long cytoplasmic processes filled with bundles of glial filaments and scarce other organelles (×2,500). (F) Glioblastoma shows many pleomorphic spindle and oval cells with numerous cytoplasmic processes containing bundles of intermediate filaments with surface microvilli-like differentiation (×2,500). (G) Medulloblastoma shows that loosely arranged oval-shaped tumor cells project cytoplasmic processes forming rosettes filled with glial filaments and dense core granules indicating neuroglial differentiation (×9,000). (H) Neuroblastoma reveals that closely packed polygonal to spherical tumor cells have numerous, thin, electron-lucent cell processes forming an interlacing meshwork between groups of cell bodies (×9,000). Inset shows longitudinally-oriented 20 nm microtubules (white arrow) and dense core granules (black arrow, ×15,000). (I) Primitive neuroectodermal tumor reveals round to closely apposed oval-shaped tumor cells with abundant cytoplasmic processes containing sparse organelles including glycogen particles, mitochondria, and some microtubules (×8,000).(J) Atypical teratoid and rhabdoid tumor reveals paranuclear aggregates of intermediate filaments (arrow) compressing the heterochromatic nuclei (×15,000). (K) Oligodendroglioma presents tumor cells with uniform round nuclei and sparse cytoplasmic organelles as well as some irregularly shaped cell processes (arrow) containing occasional globoid collections of intermediate filaments (×3,500). (L) Neurocytoma reveals round tumor cells with a moderate amount of cytoplasm and numerous long thin cell processes containing microtubules, few electron dense core granules and secretory vesicles (arrow), and glial intermediate filaments (×8,000). (M) Dysembryoplastic neuroepithelial tumor reveals oligodendroglial-like cells with elongated bulbous cell processes forming a neuropil-like structure filled with intermediate filaments in electron-lucent mucoid extracellular spaces (×7,000).(N) Papillary tumor of the pineal region reveals polygonal-shaped tumor cells having short-villous cell surfaces and cytoplasm having abundant rough endoplasmic reticulums with distended cisternae and vacuoles (×3,500). (O) Chordoid glioma of the third ventricle reveals tumor cells with cytoplasmic processes filled with intermediate glial filaments and surrounded by basal lamina (×7,000). Note the numerous surface microvilli (arrow). (P) Choroid plexus papilloma shows ovoid to polygonal tumor cells arranged in glandular patterns joined by well-formed junctional complexes and a continuous basal lamina (arrow) surrounding these glandular structures (×1,500). Note the apical portion of tumor cells lined by numerous microvilli and cilia composed of 9+2 microtubules.

Mentions: First, the spindle cell category includes the following entities: meningioma, schwannoma, ependymoma, and astrocytoma including pilocytic astrocytoma, and pilomyxoid astrocytoma. Among these, ependymoma and pilocytic astrocytoma are common in children, while meningioma or schwannoma are not common. Rather, meningioma associated with meningioangiomatosis has been reported mainly in childhood [5]. Previous reports on meningioma arising in meningioangiomatosis describe entrapped neurons in the infiltrating meningioma [15]. Ultrastructural findings of meningioma show its meningothelial arachnoidal cell nature, i.e., epithelial and mesenchymal nature; connective tissue fibers and basal lamina are not usually seen among tumor cells within the syncytium (Fig. 1A). Elongated interdigitating cell processes filled with copious amounts of intracytoplasmic intermediate filaments show an interdigitating and jigsaw pattern, corresponding to the whorls of enwrapping meningioma tumor cells under light microscopy. The epithelial nature, such as well-formed desmosomes, is a characteristic ultrastructural feature. The extracellular space of meningioma sometimes contains fine granular materials, mimicking basal lamina. Meningiomas also show basement membrane separating the syncytium from the fibrous septum or the perivascular connective tissue [16]. Rhabdoid or chordoid meningioma can have a thick continuous basal lamina [17-19]. Schwannoma, also called neurilemmoma, neuroma, or neurinoma, is relatively rare in the brain with or without cranial nerve-relation. Intracerebral schwannomas not related to cranial nerves are rare, and most cases occur in the first two decades of life [20]. Schwannoma can be diagnosed in children who might be associated with neurofibromatosis type 2, while intracerebral schwannomas have a weak relationship with neurofibromatosis type 2. The ultrastructure of schwannoma is almost exclusively cells with characteristics of differentiated Schwann cells of a neuroectodermal origin. Numerous finger-like cytoplasmic processes are lined by continuous basal lamina with occasional duplication (Fig. 1B). Closely apposed stacks of plasma membrane, i.e., reminiscent of myelin lamellae, are characteristic of schwannoma. Compared to normal collagen fibers of 64-nm periodicity, so-called Luse bodies show more widely spaced collagen fibers with up to 150-nm periodicity and are frequently found in schwannoma. The tumor cells themselves are composed of cigar-shaped or elliptical nuclei containing one or two small nucleoli and rare nuclear bodies. The cytoplasm contains well-developed Golgi complexes, scattered mitochondria, short segments of rough endoplasmic reticulums (RERs), small numbers of ribosomes, and scattered polysomes. Absence of pinocytotic vesicles always happens in schwannoma. Microfilaments, microtubules, and small vesicles are often found, but few mitochondria and ribosomes are found. These ultrastructural characteristics of schwannoma provide diagnostic clues, particularly regarding small cell changes in schwannoma or small cell malignant peripheral nerve sheath tumors [21,22]. Ependymoma occurs mainly in the ventricular system, and infratentorial ependymomas occur predominantly in children, although development of ependymomas can occur at any age [23-25]. Ultrastructural findings of a well-developed ependymal tumor, which is likely derived from ependymal cells lining the CNS ventricular system, show both epithelial and astrocytic features, and the tumor cells of grade I and II ependymal tumors resemble typical ependymocytes, while anaplastic ependymomas are poorly differentiated with minimal evidence of such ependymal differentiation. Ependymal differentiation includes well-developed junctions, such as zonula adherens or occludens, villous projections, and cilia in a 9+2 arrangement of microtubules (Fig. 1C). The centriole or blepharoplast is located in the basis of the cilia; in the cytoplasm, microtubules or glial filaments are present in the perikaryal area or cytoplasmic processes. Basal lamina is observed in the ependymoma and around blood vessels but not around tumor cells [26]. However, all of the above-mentioned findings are not specific for ependymomas; these ultrastructural findings are shared by angiocentric glioma, i.e., monomorphous angiocentric neuroepithelial tumor, composed of bipolar spindle cells and epithelioid round cells although the occurrence of angiocentric glioma has not yet been reported in children [9]. Angiocentric glioma is composed of infiltrating round, monopolar epithelioid cells arranged in a perivascular arrangement and bipolar spindle-shaped glial cells. Epithelioid monopolar cells showing microlumina filled with numerous microvilli and some cilia with a 9+2 or abnormal 10+2 configuration. Intermediate junctions of complex interdigitating membranes and basal lamina have also been observed [27]. Ependymomas and angiocentric glioma share molecular cytogenetic alterations, as indicated by shared ultrastructural features [28]. These findings suggest that angiocentric glioma belongs to a lineage of ependymal tumors.


The Continuing Value of Ultrastructural Observation in Central Nervous System Neoplasms in Children.

Kim NR, Park SH - J Pathol Transl Med (2015)

(A) Meningioma shows closely apposed oval- to spindle-shaped tumor cells having interdigitating cell processes lined by well-formed desmosomes (×8,000). Inset indicates tonofibrils attached to the desmosomal plaques (×30,000). (B) Schwannoma shows abundant reduplicated continuous basal lamina surrounding the interdigitating cell processes (×3,500). Note the extracellular long-spacing collagen (arrow) and high power view of reduplicated basal lamina (inset, ×6,500). (C) Ependymoma reveals spindle cells with numerous cytoplasmic processes filled with bundles of intermediate filaments (×4,000). Inset shows well-formed zonula occludens with surface microvilli (×15,000). (D) Pilomyxoid astrocytoma shows bipolar cells with surface microvilli and cilia in the electron-lucent extracellular space (×9,000). Note some intracellular microlumen. (E) Astrocytoma shows loosely scattered round to oval cells having numerous long cytoplasmic processes filled with bundles of glial filaments and scarce other organelles (×2,500). (F) Glioblastoma shows many pleomorphic spindle and oval cells with numerous cytoplasmic processes containing bundles of intermediate filaments with surface microvilli-like differentiation (×2,500). (G) Medulloblastoma shows that loosely arranged oval-shaped tumor cells project cytoplasmic processes forming rosettes filled with glial filaments and dense core granules indicating neuroglial differentiation (×9,000). (H) Neuroblastoma reveals that closely packed polygonal to spherical tumor cells have numerous, thin, electron-lucent cell processes forming an interlacing meshwork between groups of cell bodies (×9,000). Inset shows longitudinally-oriented 20 nm microtubules (white arrow) and dense core granules (black arrow, ×15,000). (I) Primitive neuroectodermal tumor reveals round to closely apposed oval-shaped tumor cells with abundant cytoplasmic processes containing sparse organelles including glycogen particles, mitochondria, and some microtubules (×8,000).(J) Atypical teratoid and rhabdoid tumor reveals paranuclear aggregates of intermediate filaments (arrow) compressing the heterochromatic nuclei (×15,000). (K) Oligodendroglioma presents tumor cells with uniform round nuclei and sparse cytoplasmic organelles as well as some irregularly shaped cell processes (arrow) containing occasional globoid collections of intermediate filaments (×3,500). (L) Neurocytoma reveals round tumor cells with a moderate amount of cytoplasm and numerous long thin cell processes containing microtubules, few electron dense core granules and secretory vesicles (arrow), and glial intermediate filaments (×8,000). (M) Dysembryoplastic neuroepithelial tumor reveals oligodendroglial-like cells with elongated bulbous cell processes forming a neuropil-like structure filled with intermediate filaments in electron-lucent mucoid extracellular spaces (×7,000).(N) Papillary tumor of the pineal region reveals polygonal-shaped tumor cells having short-villous cell surfaces and cytoplasm having abundant rough endoplasmic reticulums with distended cisternae and vacuoles (×3,500). (O) Chordoid glioma of the third ventricle reveals tumor cells with cytoplasmic processes filled with intermediate glial filaments and surrounded by basal lamina (×7,000). Note the numerous surface microvilli (arrow). (P) Choroid plexus papilloma shows ovoid to polygonal tumor cells arranged in glandular patterns joined by well-formed junctional complexes and a continuous basal lamina (arrow) surrounding these glandular structures (×1,500). Note the apical portion of tumor cells lined by numerous microvilli and cilia composed of 9+2 microtubules.
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getmorefigures.php?uid=PMC4696531&req=5

f1-jptm-2015-09-19: (A) Meningioma shows closely apposed oval- to spindle-shaped tumor cells having interdigitating cell processes lined by well-formed desmosomes (×8,000). Inset indicates tonofibrils attached to the desmosomal plaques (×30,000). (B) Schwannoma shows abundant reduplicated continuous basal lamina surrounding the interdigitating cell processes (×3,500). Note the extracellular long-spacing collagen (arrow) and high power view of reduplicated basal lamina (inset, ×6,500). (C) Ependymoma reveals spindle cells with numerous cytoplasmic processes filled with bundles of intermediate filaments (×4,000). Inset shows well-formed zonula occludens with surface microvilli (×15,000). (D) Pilomyxoid astrocytoma shows bipolar cells with surface microvilli and cilia in the electron-lucent extracellular space (×9,000). Note some intracellular microlumen. (E) Astrocytoma shows loosely scattered round to oval cells having numerous long cytoplasmic processes filled with bundles of glial filaments and scarce other organelles (×2,500). (F) Glioblastoma shows many pleomorphic spindle and oval cells with numerous cytoplasmic processes containing bundles of intermediate filaments with surface microvilli-like differentiation (×2,500). (G) Medulloblastoma shows that loosely arranged oval-shaped tumor cells project cytoplasmic processes forming rosettes filled with glial filaments and dense core granules indicating neuroglial differentiation (×9,000). (H) Neuroblastoma reveals that closely packed polygonal to spherical tumor cells have numerous, thin, electron-lucent cell processes forming an interlacing meshwork between groups of cell bodies (×9,000). Inset shows longitudinally-oriented 20 nm microtubules (white arrow) and dense core granules (black arrow, ×15,000). (I) Primitive neuroectodermal tumor reveals round to closely apposed oval-shaped tumor cells with abundant cytoplasmic processes containing sparse organelles including glycogen particles, mitochondria, and some microtubules (×8,000).(J) Atypical teratoid and rhabdoid tumor reveals paranuclear aggregates of intermediate filaments (arrow) compressing the heterochromatic nuclei (×15,000). (K) Oligodendroglioma presents tumor cells with uniform round nuclei and sparse cytoplasmic organelles as well as some irregularly shaped cell processes (arrow) containing occasional globoid collections of intermediate filaments (×3,500). (L) Neurocytoma reveals round tumor cells with a moderate amount of cytoplasm and numerous long thin cell processes containing microtubules, few electron dense core granules and secretory vesicles (arrow), and glial intermediate filaments (×8,000). (M) Dysembryoplastic neuroepithelial tumor reveals oligodendroglial-like cells with elongated bulbous cell processes forming a neuropil-like structure filled with intermediate filaments in electron-lucent mucoid extracellular spaces (×7,000).(N) Papillary tumor of the pineal region reveals polygonal-shaped tumor cells having short-villous cell surfaces and cytoplasm having abundant rough endoplasmic reticulums with distended cisternae and vacuoles (×3,500). (O) Chordoid glioma of the third ventricle reveals tumor cells with cytoplasmic processes filled with intermediate glial filaments and surrounded by basal lamina (×7,000). Note the numerous surface microvilli (arrow). (P) Choroid plexus papilloma shows ovoid to polygonal tumor cells arranged in glandular patterns joined by well-formed junctional complexes and a continuous basal lamina (arrow) surrounding these glandular structures (×1,500). Note the apical portion of tumor cells lined by numerous microvilli and cilia composed of 9+2 microtubules.
Mentions: First, the spindle cell category includes the following entities: meningioma, schwannoma, ependymoma, and astrocytoma including pilocytic astrocytoma, and pilomyxoid astrocytoma. Among these, ependymoma and pilocytic astrocytoma are common in children, while meningioma or schwannoma are not common. Rather, meningioma associated with meningioangiomatosis has been reported mainly in childhood [5]. Previous reports on meningioma arising in meningioangiomatosis describe entrapped neurons in the infiltrating meningioma [15]. Ultrastructural findings of meningioma show its meningothelial arachnoidal cell nature, i.e., epithelial and mesenchymal nature; connective tissue fibers and basal lamina are not usually seen among tumor cells within the syncytium (Fig. 1A). Elongated interdigitating cell processes filled with copious amounts of intracytoplasmic intermediate filaments show an interdigitating and jigsaw pattern, corresponding to the whorls of enwrapping meningioma tumor cells under light microscopy. The epithelial nature, such as well-formed desmosomes, is a characteristic ultrastructural feature. The extracellular space of meningioma sometimes contains fine granular materials, mimicking basal lamina. Meningiomas also show basement membrane separating the syncytium from the fibrous septum or the perivascular connective tissue [16]. Rhabdoid or chordoid meningioma can have a thick continuous basal lamina [17-19]. Schwannoma, also called neurilemmoma, neuroma, or neurinoma, is relatively rare in the brain with or without cranial nerve-relation. Intracerebral schwannomas not related to cranial nerves are rare, and most cases occur in the first two decades of life [20]. Schwannoma can be diagnosed in children who might be associated with neurofibromatosis type 2, while intracerebral schwannomas have a weak relationship with neurofibromatosis type 2. The ultrastructure of schwannoma is almost exclusively cells with characteristics of differentiated Schwann cells of a neuroectodermal origin. Numerous finger-like cytoplasmic processes are lined by continuous basal lamina with occasional duplication (Fig. 1B). Closely apposed stacks of plasma membrane, i.e., reminiscent of myelin lamellae, are characteristic of schwannoma. Compared to normal collagen fibers of 64-nm periodicity, so-called Luse bodies show more widely spaced collagen fibers with up to 150-nm periodicity and are frequently found in schwannoma. The tumor cells themselves are composed of cigar-shaped or elliptical nuclei containing one or two small nucleoli and rare nuclear bodies. The cytoplasm contains well-developed Golgi complexes, scattered mitochondria, short segments of rough endoplasmic reticulums (RERs), small numbers of ribosomes, and scattered polysomes. Absence of pinocytotic vesicles always happens in schwannoma. Microfilaments, microtubules, and small vesicles are often found, but few mitochondria and ribosomes are found. These ultrastructural characteristics of schwannoma provide diagnostic clues, particularly regarding small cell changes in schwannoma or small cell malignant peripheral nerve sheath tumors [21,22]. Ependymoma occurs mainly in the ventricular system, and infratentorial ependymomas occur predominantly in children, although development of ependymomas can occur at any age [23-25]. Ultrastructural findings of a well-developed ependymal tumor, which is likely derived from ependymal cells lining the CNS ventricular system, show both epithelial and astrocytic features, and the tumor cells of grade I and II ependymal tumors resemble typical ependymocytes, while anaplastic ependymomas are poorly differentiated with minimal evidence of such ependymal differentiation. Ependymal differentiation includes well-developed junctions, such as zonula adherens or occludens, villous projections, and cilia in a 9+2 arrangement of microtubules (Fig. 1C). The centriole or blepharoplast is located in the basis of the cilia; in the cytoplasm, microtubules or glial filaments are present in the perikaryal area or cytoplasmic processes. Basal lamina is observed in the ependymoma and around blood vessels but not around tumor cells [26]. However, all of the above-mentioned findings are not specific for ependymomas; these ultrastructural findings are shared by angiocentric glioma, i.e., monomorphous angiocentric neuroepithelial tumor, composed of bipolar spindle cells and epithelioid round cells although the occurrence of angiocentric glioma has not yet been reported in children [9]. Angiocentric glioma is composed of infiltrating round, monopolar epithelioid cells arranged in a perivascular arrangement and bipolar spindle-shaped glial cells. Epithelioid monopolar cells showing microlumina filled with numerous microvilli and some cilia with a 9+2 or abnormal 10+2 configuration. Intermediate junctions of complex interdigitating membranes and basal lamina have also been observed [27]. Ependymomas and angiocentric glioma share molecular cytogenetic alterations, as indicated by shared ultrastructural features [28]. These findings suggest that angiocentric glioma belongs to a lineage of ependymal tumors.

Bottom Line: Diagnostic dilemmas with small specimens from CNS neoplasms are often the result of multifactorial etiologies such as frozen or fixation artifact, biopsy size, or lack of knowledge about rare or unfamiliar entities.Nowadays, pathologic diagnosis of CNS neoplasms is achieved through intraoperative cytology, light microscopy, immunohistochemistry, and molecular cytogenetic results.Here, we reviewed the distinguishing ultrastructural features of pediatric CNS neoplasms and emphasize the continuing value of EM in the diagnosis of CNS neoplasms.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Gachon University Gil Medical Center, Incheon, Korea.

ABSTRACT
Central nervous system (CNS) neoplasms are the second most common childhood malignancy after leukemia and the most common solid organ neoplasm in children. Diagnostic dilemmas with small specimens from CNS neoplasms are often the result of multifactorial etiologies such as frozen or fixation artifact, biopsy size, or lack of knowledge about rare or unfamiliar entities. Since the late 1950s, ultrastructural examination has been used in the diagnosis of CNS neoplasms, though it has largely been replaced by immunohistochemical and molecular cytogenetic studies. Nowadays, pathologic diagnosis of CNS neoplasms is achieved through intraoperative cytology, light microscopy, immunohistochemistry, and molecular cytogenetic results. However, the utility of electron microscopy (EM) in the final diagnosis of CNS neoplasms and investigation of its pathogenetic origin remains critical. Here, we reviewed the distinguishing ultrastructural features of pediatric CNS neoplasms and emphasize the continuing value of EM in the diagnosis of CNS neoplasms.

No MeSH data available.


Related in: MedlinePlus