Flexner-Wintersteiner rosette is a spoke and wheel shaped cell

Cell (biology)

The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....

 formation seen in 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 certain other ophthalmic

Ophthalmology

Ophthalmology is the branch of medicine that deals with the anatomy, physiology and diseases of the eye. An ophthalmologist is a specialist in medical and surgical eye problems...

 tumor

Tumor

A tumor or tumour is commonly used as a synonym for a neoplasm that appears enlarged in size. Tumor is not synonymous with cancer...

s. A rosette is a structure or formation resembling a rose

Rose

A rose is a woody perennial of the genus Rosa, within the family Rosaceae. There are over 100 species. They form a group of erect shrubs, and climbing or trailing plants, with stems that are often armed with sharp prickles. Flowers are large and showy, in colours ranging from white through yellows...

, such as the clusters of polymorphonuclear leukocytes around a globule of lipid nuclear material, as observed in the test for disseminated lupus erythematosus

Lupus erythematosus

Lupus erythematosus is a category for a collection of diseases with similar underlying problems with immunity . Symptoms of these diseases can affect many different body systems, including joints, skin, kidneys, blood cells, heart, and lungs...

.

History

Flexner-Wintersteiner rosettes were first described by Simon Flexner

Simon Flexner

Simon Flexner, M.D. was a physician, scientist, administrator, and professor of experimental pathology at the University of Pennsylvania . He was the first director of the Rockefeller Institute for Medical Research and a trustee of the Rockefeller Foundation...

 (1863–1946), a physician

Physician

A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...

, scientist

Scientist

A scientist in a broad sense is one engaging in a systematic activity to acquire knowledge. In a more restricted sense, a scientist is an individual who uses the scientific method. The person may be an expert in one or more areas of science. This article focuses on the more restricted use of the word...

, administrator

Academic administration

An academic administration is a branch of university or college employees responsible for the maintenance and supervision of the institution and separate from the faculty or academics, although some personnel may have joint responsibilities...

, and professor

Professor

A professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...

 of experimental pathology

Pathology

Pathology is the precise study and diagnosis of disease. The word pathology is from Ancient Greek , pathos, "feeling, suffering"; and , -logia, "the study of". Pathologization, to pathologize, refers to the process of defining a condition or behavior as pathological, e.g. pathological gambling....

 at the University of Pennsylvania

University of Pennsylvania

The University of Pennsylvania is a private, Ivy League university located in Philadelphia, Pennsylvania, United States. Penn is the fourth-oldest institution of higher education in the United States,Penn is the fourth-oldest using the founding dates claimed by each institution...

 (1899–1903). Flexner noted characteristic clusters of cells in an infantile eye tumor

Ocular oncology

Ocular oncology is the branch of medicine dealing with tumors relating to the eye and its adnexa. Eye cancer can affect all parts of the eye.-Origin and location:...

 which he called retinoepithelioma. A few years later, in 1897, Austrian

Austrians

Austrians are a nation and ethnic group, consisting of the population of the Republic of Austria and its historical predecessor states who share a common Austrian culture and Austrian descent....

 ophthalmologist Hugo Wintersteiner (1865–1946) confirmed Flexner’s observations and noted that the cell clusters resembled rods and cones. These characteristic rosette formations were subsequently recognized as important features of retinoblastomas.

Characteristics

The tumor cells that form the Flexner-Wintersteiner rosette surround a central lumen containing small cytoplasmic extensions of the encircling cells. Unlike the center of the Homer Wright rosette

Homer-Wright rosette

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...

, the central lumen is devoid of fiber-rich neuropil. Like the Homer Wright rosette, the Flexner-Wintersteiner rosette represents a specific form of tumor differentiation. Electron microscopy reveals that the tumor cells forming the Flexner-Wintersteiner rosette have ultrastructural features of primitive photoreceptor cells. Furthermore, the rosette lumen shows similar staining patterns as in rods and cones, suggesting that Flexner-Wintersteiner rosettes represent a specific form of retinal differentiation. In addition to being a characteristic finding in retinoblastomas, Flexner-Wintersteiner rosettes may also be found in 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....

s and medulloepithelioma

Medulloepithelioma

Medulloepithelioma is a rare, primitive, fast growing brain tumour thought to stem from cells of the embryonic medullary cavity. Tumours originating in the ciliary body of the eye are referred to as embryonal medulloepitheliomas, or diktyomas....

s.