Webster's New World Medical Dictionary

pineal region tumor
A brain tumor on or near
the pineal gland. There are multiple types of pineal
gland tumors, most of which are not cancerous but
can nonetheless cause extreme distress. Diagnosis
is made via biopsy of affected tissue. Benign pineal
tumors are treated with surgery; malignant tumors
may be treated with surgery, radiation therapy,
and/or chemotherapy.
pinealoblastoma
See 
pineoblastoma.
pinealocytoma
See 
pinealoma.
pinealoma
An uncommon slow-growing tumor
of the pineal gland. Also known as a pinealocytoma
and pineocytoma.
pineoblastoma
A fast-growing brain tumor in
the pineal gland that originates in neuroepithelial
cells. This malignancy is considered by many to be
one of the primitive neuroectodermal tumors
(PNETs). Also known as pinealoblastoma.
pineocytoma
See 
pinealoma.
pinguecula
A yellow spot on the conjunctiva (the
membrane that lines the sclera—the “white” of the
eye—and the eyelids) usually toward the inside of
the eye, that is believed to be related to ultraviolet
light exposure or other irritants. A pinguecula looks
fatty and is due to an accumulation of connective tis-
sue. Also known as pinguicula.
pinguicula
See 
pinguecula.
pinkeye
See 
conjunctivitis.
pinna 1
The ear.
2
The part of the ear that pro-
jects like a wing from the head.
pinworm infestation
An infestation of the intes-
tinal tract by small, white pinworms (Enterobius
vermicularis). Pinworms are about the length of a
staple, and they live for the most part within the
human rectum. While a pinworm-infested person is
asleep, female pinworms leave the intestines
through the anus and deposit eggs on the skin
around the anus. Most symptoms of pinworms are