Pathological staging of glioma.
Pathological typing
1. Overview.
Gliomas are derived from the supporting tissues of the nervous system and are ectodermal tumors. Many gliomas have tumor cells that resemble mature or immature glial cells
2.Typing.
(1) astrocytoma
① Occurrence.
It occurs from astrocytes and accounts for more than half of gliomas, mostly in the cerebral hemispheres in adults and in the cerebellum in children. Other tumors such as thalamus, brainstem and spinal cord can occur. Astrocytomas can be divided into two types: fibrous and protoplasmic.
② Gross morphology.
Fibrous astrocytomas are hard and tough, while protoplasmic astrocytomas are soft and often have cystic changes. Intratumoral hemorrhage and necrosis are relatively rare.
③Microscopic morphology.
The tumor tissue consists of more mature differentiated astrocytes. Fibrous astrocytoma is rich in glial fibers, and protoplasmic astrocytoma is rich in cytoplasm. If the astrocytes are more dense, the cells have heterotypy, and filiform nuclear division images are seen, the vascular endothelial cells and epithelial cells are proliferated, and small focal hemorrhage and necrosis are seen, it is called astroblastoma, or poorly differentiated astrocytoma.
(2) Glioblastoma multiforme
(1) Occurrence.
It is a relatively common malignant glioma in adults, second only to astrocytoma in incidence, occurring mostly in the cerebral hemispheres and rarely in the cerebellum.
② Gross morphology.
Tumor infiltration is relatively large and can invade several brain lobes or the contralateral cerebral hemisphere via the corpus callosum. The tumor is soft and gray-red in color, often with large areas of hemorrhage and necrosis, and the peritumor tissue is significantly edematous or even liquefied, with pseudo-demarcation, in fact, the infiltration of tumor cells is much more extensive than what is seen with the naked eye.
(iii) Microscopic morphology.
Tumor cells are immaturely differentiated, pleomorphic, heterogeneous, with more nuclear division images, often mononuclear and multinucleated tumor giant cells, significant proliferation of vascular endothelial cells and epithelial cells, thrombosis in the lumen of blood vessels, scattered large areas of hemorrhage and necrosis and poorly differentiated astroblastoma without clear zones.
(3) Oligodendroglial cell tumor and oligodendroglioblastoma
(1) Occurrence.
Occurring from oligodendroglial cells, patients are mostly middle-aged, but also seen in children, mainly in the white matter of the cerebral hemispheres
②Morphology.
The tumor is soft, gray-red, poorly defined, often with calcification and cystic changes
③Microscopic morphology.
The tumor cell morphology is relatively consistent, the nucleus is round, deeply stained, the perinuclear cytoplasm is blank due to edema, there is little interstitium, common foci of calcification and cyst formation If the tumor cell size, morphology, nuclear staining is inconsistent, and there are giant tumor cells with nuclear division image, vascular endothelial cell hyperplasia, hemorrhage and necrosis, it is called oligodendroglioblastoma
(4) Ventricular meningioma and ventriculoblastoma
(1) Occurrence
They are often associated with the ventricular wall and central canal, and are found in the fourth ventricle, lateral ventricle and spinal cord, and most patients are young children and young adults. The tumors are gray-red, soft, and nodular in the ventricular cavity or in the brain or spinal cord parenchyma.
(3) Microscopic morphology: ventricular meningioma is divided into four types: epithelial type, papillary type, papillary mucinous type and cellular type.
(5) Mixed glioma
The tumor is composed of two or more glioma types, each accounting for a considerable fraction of the tumor. This kind of glioma is mostly seen in pediatric patients and can be seen in the cerebellum and brain, and the morphology of the glioma is no different from that of general glioma when observed by the naked eye, and relies on histological examination for diagnosis.
(6) Medulloblastoma
①Occurrence
It is a common malignant tumor in pediatric cranium, mainly occurs in the cerebellar earth, may protrude into the fourth ventricle, and may also invade the surrounding tissues, and often spreads along the cerebrospinal fluid in an implantation manner.
② Gross morphology.
The tumor is purplish red, mucous jelly-like, with indistinct boundary between brain parenchyma, and hemorrhagic necrosis is rare
③Microscopic morphology.
Tumor cells are dense, with little interstitium, small tumor cells, garden-shaped or oval nuclei, deep staining, little cytoplasm, nuclear fission images are often seen, cells are often arranged in pseudo-chrysanthemum shape, if the tumor invades the soft membrane, it is often accompanied by obvious hyperplasia of fibrous connective tissue.
(7) Choroid plexus papilloma
①Occurrence
It occurs in the intracerebroventricular choroid plexus, usually in the fourth ventricle and lateral ventricle, and may grow in the pontocerebellar horn through the lateral foramen of the fourth ventricle.
(2) Gross morphology: the tumor is pink in color, soft in texture, with a fluffy surface and common calcification.
③Microscopic morphology.
The tumor tissue is papillary-like structure, covered with well-differentiated epithelial cells, and may have calcification or sand vesicles formation, and its malignant type is called choroid plexus papillary carcinoma.
① Occurrence
It is relatively rare, mostly occurs in young people, and is commonly found in the posterior part of the third ventricle, i.e. the pineal gland area.
② Gross morphology.
The tumor is grayish red, spherical, without envelope formation
③Microscopic morphology.
The tumor tissue is composed of single epithelial-like cells with medium-sized cytosol, round or oval nucleus, containing more chromatin and deep staining, mostly without nucleolus, light cytoplasm and poorly defined, distributed in the interstitium formed by fibrous tissue, generally without nuclear division like pineoblastoma, which is composed of dense small cells with low differentiation, small and dense nucleus, little cytoplasm, and very deep staining, morphology is very similar to medulloblastoma of cerebellum. The morphology is very similar to the medulloblastoma of the cerebellum.