Hemangiopericytoma
Encyclopedia
A hemangeopericytoma is a type of soft tissue sarcoma
that originates in the pericyte
s in the walls of capillaries
. When inside the nervous system
, although not strictly a meningioma
tumor, it is a meningeal
tumor with an especially aggressive behavior.
It was characterized in 1942.
with oval nuclei with scant cytoplasm. "There is dense intercellular reticulin staining. Tumor cells can be fibroblastic, myxoid
, or pericytic
. These tumors, in contrast to meningiomas, do not stain with epithelial membrane antigen. They have a grade 2 or 3 biological behavior, and need to be distinguished from benign meningiomas because of their high rate of recurrence (68.2%) and metastases (Maier et al 1992 ; Kleihues et al 1993 )."
, chemotherapy
and/or radiotherapy.
Soft tissue sarcoma
A soft-tissue sarcoma is a form of sarcoma that develops in connective tissue, though the term is sometimes applied to elements of the soft tissue that are not currently considered connective tissue.-Risk factors:...
that originates in the pericyte
Pericyte
A pericyte is a type of cell found in the central nervous system. These cells play an integral role in the maintenance of the blood brain barrier as well as several other homeostatic and hemostatic functions of the brain. Pericytes are also a key component of the neurovascular unit, which also...
s in the walls of capillaries
Capillary
Capillaries are the smallest of a body's blood vessels and are parts of the microcirculation. They are only 1 cell thick. These microvessels, measuring 5-10 μm in diameter, connect arterioles and venules, and enable the exchange of water, oxygen, carbon dioxide, and many other nutrient and waste...
. When inside the nervous system
Nervous system
The nervous system is an organ system containing a network of specialized cells called neurons that coordinate the actions of an animal and transmit signals between different parts of its body. In most animals the nervous system consists of two parts, central and peripheral. The central nervous...
, although not strictly a meningioma
Meningioma
The word meningioma was first used by Harvey Cushing in 1922 to describe a tumor originating from the meninges, the membranous layers surrounding the CNS ....
tumor, it is a meningeal
Meninges
The meninges is the system of membranes which envelopes the central nervous system. The meninges consist of three layers: the dura mater, the arachnoid mater, and the pia mater. The primary function of the meninges and of the cerebrospinal fluid is to protect the central nervous system.-Dura...
tumor with an especially aggressive behavior.
It was characterized in 1942.
Description
Hemangiopericytoma located in the cerebral cavity is an aggressive tumor of the MesenchymeMesenchyme
Mesenchyme, or mesenchymal connective tissue, is a type of undifferentiated loose connective tissue that is derived mostly from mesoderm, although some are derived from other germ layers; e.g. some mesenchyme is derived from neural crest cells and thus originates from the ectoderm...
with oval nuclei with scant cytoplasm. "There is dense intercellular reticulin staining. Tumor cells can be fibroblastic, myxoid
Mucous membrane
The mucous membranes are linings of mostly endodermal origin, covered in epithelium, which are involved in absorption and secretion. They line cavities that are exposed to the external environment and internal organs...
, or pericytic
Pericyte
A pericyte is a type of cell found in the central nervous system. These cells play an integral role in the maintenance of the blood brain barrier as well as several other homeostatic and hemostatic functions of the brain. Pericytes are also a key component of the neurovascular unit, which also...
. These tumors, in contrast to meningiomas, do not stain with epithelial membrane antigen. They have a grade 2 or 3 biological behavior, and need to be distinguished from benign meningiomas because of their high rate of recurrence (68.2%) and metastases (Maier et al 1992 ; Kleihues et al 1993 )."
Treatment
Depending of the grade of the sarcoma, it is treated with surgerySurgery
Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...
, chemotherapy
Chemotherapy
Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....
and/or radiotherapy.