A neuroectodermal neoplasm is a

neoplasm A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

tumor A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

of the

neuroectoderm Neuroectoderm (or neural ectoderm or neural tube epithelium) consists of cells derived from the ectoderm. Formation of the neuroectoderm is the first step in the development of the nervous system. The neuroectoderm receives bone morphogenetic pro ...

.Neuroectodermal tumor
entry in the public domain NCI Dictionary of Cancer Terms They are most commonly tumors in the central or

peripheral nervous system The peripheral nervous system (PNS) is one of two components that make up the nervous system of Bilateria, bilateral animals, with the other part being the central nervous system (CNS). The PNS consists of nerves and ganglia, which lie outside t ...

. Tumors exhibiting neuroectodermal differentiation are classified into two main groups: * Group I tumors/neoplasms: neuroendocrine carcinomas. These show predominantly epithelial differentiation. They include

pituitary adenoma Pituitary adenomas are tumors that occur in the pituitary gland. Most pituitary tumors are benign, approximately 35% are invasive and just 0.1% to 0.2% are carcinomas.carcinoid tumor A carcinoid (also carcinoid tumor) is a slow-growing type of neuroendocrine tumor Neuroendocrine tumors (NETs) are neoplasms that arise from cells of the endocrine (hormonal) and nervous systems. They most commonly occur in the intestine, whe ...

* Group II tumors/neoplasms: nonepithelial neuroectodermal neoplasms. These are predominantly neural in origin. They include

malignant melanoma Melanoma is the most dangerous type of skin cancer; it develops from the melanin-producing cells known as melanocytes. It typically occurs in the skin, but may rarely occur in the mouth, intestines, or eye (uveal melanoma). In very rare case ...

, olfactory neuroblastoma and Ewing's sarcoma.

References

Anatomical pathology Nervous system neoplasia {{oncology-stub