Homer-Wright rosette
Encyclopedia
Homer-Wright rosettes are a type of rosette in which differentiated tumor cells surround the neuropil
. Examples of tumors containing these are neuroblastoma
, medulloblastoma
, retinoblastoma
, and pinealoblastoma
. Homer-Wright rosettes are considered "pseudo" in the sense they are not the true rosettes. True rosettes are Flexner-Wintersteiner rosette
which contain an empty lumen.
Neuropil
In neuroanatomy, a neuropil, which is sometimes referred to as a neuropile, is a region between neuronal cell bodies in the gray matter of the brain and blood-brain barrier . It consists of a dense tangle of axon terminals, dendrites and glial cell processes...
. Examples of tumors containing these are neuroblastoma
Neuroblastoma
Neuroblastoma is the most common extracranial solid cancer in childhood and the most common cancer in infancy, with an annual incidence of about 650 cases per year in the US , and 100 cases per year in the UK . Close to 50 percent of neuroblastoma cases occur in children younger than two years old...
, medulloblastoma
Medulloblastoma
Medulloblastoma is a highly malignant primary brain tumor that originates in the cerebellum or posterior fossa.Previously, medulloblastomas were thought to represent a subset of primitive neuroectodermal tumor of the posterior fossa...
, retinoblastoma
Retinoblastoma
Retinoblastoma is a rapidly developing cancer that develops in the cells of retina, the light-detecting tissue of the eye. In the developed world, Rb has one of the best cure rates of all childhood cancers , with more than nine out of every ten sufferers surviving into...
, and pinealoblastoma
Pinealoblastoma
Pinealoblastoma is a tumor of the pineal gland.Retinoblastoma can be characterized as "bilateral" when it presents on both sides. It can also be characterized as "trilateral" when it presents with pinealoblastoma....
. Homer-Wright rosettes are considered "pseudo" in the sense they are not the true rosettes. True rosettes are Flexner-Wintersteiner rosette
Flexner-Wintersteiner rosette
Flexner-Wintersteiner rosette is a spoke and wheel shaped cell formation seen in retinoblastoma and certain other ophthalmic tumors. A rosette is a structure or formation resembling a rose, such as the clusters of polymorphonuclear leukocytes around a globule of lipid nuclear material, as observed...
which contain an empty lumen.