Webster's New World Medical Dictionary

penis, cancer of the
See 
cancer, penis
penis, erection of the
See 
erection, penile.
penis, hypospadias of the
See 
hypospadias.
penis, inflammation of the foreskin and glans
See 
balanoposthitis.
penis, inflammation of the head of the
See
balanitis.
penis, small
See 
micropenis.
peptic ulcer
See 
ulcer, peptic.
percentile
The percentage of individuals in a
group who have achieved a certain quantity—such
as height, weight, or head circumference—or a
developmental milestone. For example, the fiftieth
percentile for walking well is 12 months of age.
percutaneous
Through the skin. For example, a
percutaneous biopsy is a biopsy that is obtained by
putting a needle through the skin in order to obtain
tissue within the body for examination.
percutaneous endoscopic gastrostomy
See
gastrostomy, percutaneous endoscopic.
percutaneous nephrolithotripsy
A technique
for removing large, dense, and staghorn kidney
stones. Abbreviated PNL. PNL is done via a port cre-
ated by puncturing through the skin and into the
kidney. The urologist then inserts instruments into
the kidney via the access port to break up the stone
and to remove most of the debris from the stone. 
percutaneous transluminal coronary angio-
plasty
The use of a balloon-tipped catheter to
enlarge a narrowed coronary artery. Abbreviated
PTCA.
percutaneous umbilical blood sampling
A
procedure in which a needle is inserted through the
mother’s abdominal wall and then through the uter-
ine wall. Abbreviated PUBS. In PUBS, blood can be
withdrawn from the umbilical vein at the point
where the umbilical cord inserts into the placenta.
Also known as umbilical vein sampling, cordocen-
tesis, and fetal blood sampling.