Neurosurgery

Fig. 3.14. Homer Wright neuroblastic pseudo-rosette in a medulloblastoma (cerebellar PNET). NP25458, H&E.

Papillae Papillae are finger-like processes of hyperplastic tumors, each process with a connective tissue stroma, usually with accompanying blood vessels, covered by epithelial cells. The best example is, of course, a choroid plexus papilloma but papillae can also be seen in ependymomas, pituitary adenomas, metastatic adenocarcinomas (Fig. 3.16) and in a rare form of meningiomas known as "papillary menin-giomas".

Checkerboard and Lattice Formations This mosaic pattern with alternating dense fibrillary and loose hypocellular areas is typically found in pilocytic astrocytomas (Fig. 3.17a, b). The loose areas represent areas of mucinous degeneration and the beginning of cyst formation. Rosenthal fibers are usually found in the dense part. A similar pattern with tumor nodules partitioned by connective tissue septa is found in optic gliomas (Fig. 3.17c).

Fig. 3.15. Perivascular crowns in an astrocytoma. NP13936, H&E.
Fig. 3.16. Papillary adenocarcinoma. NP16375, H&E.
Cure Your Yeast Infection For Good

Cure Your Yeast Infection For Good

The term vaginitis is one that is applied to any inflammation or infection of the vagina, and there are many different conditions that are categorized together under this ‘broad’ heading, including bacterial vaginosis, trichomoniasis and non-infectious vaginitis.

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