Pineocytoma

Pineocytoma
Classification and external resources
Micrograph of a pineocytoma. HPS stain.
ICD-10	C75.3
ICD-O:	M9361/1
MeSH	D010871

Pineocytoma, also known as a pinealocytoma, is a benign, slowly-growing tumor of the pineal gland. Unlike the similar condition pineal gland cyst, it is uncommon.

Diagnosis

Pineocytomas are diagnosed from tissue, i.e. a brain biopsy.

They consist of:

• cytologically benign cells (with nuclei of uniform size, regular nuclear membranes, and light chromatin) and,
• have the characteristic pineocytomatous/neurocytic rosettes, which is an irregular circular/flower-like arrangement of cells with a large meshwork of fibers (neuropil) at the centre.^[1]

Pineocytomatous/neurocytic rosettes are superficially similar to Homer-Wright rosettes; however, they differ from Homer-Wright rosettes as they have (1) more neuropil at centre of the rosette and, (2) the edge of neuropil meshwork irregular/undulating.

See Also

Pineal gland

References

1. ^ Wippold FJ, Perry A (March 2006). "Neuropathology for the neuroradiologist: rosettes and pseudorosettes". AJNR Am J Neuroradiol 27 (3): 488–92. PMID 16551982.