P–R

Paget’s disease of the breast A rare presentation
of BREAST CANCER, also called Paget’s disease of the
nipple. Researchers believe Paget’s disease of the
BREASToccurs when disordered cells from a cancer
within the breast migrate to the SKINsurface, most
likely through the milk ducts, to infiltrate the tis-
sues of the outer breast and the nipple. Paget’s dis-
ease of the breast is most commonly associated
with an underlying invasive breast cancer or duc-
tal cancer in situ (DCIS).
The symptoms of Paget’s disease of the breast
may develop over months to years, and typically
begin with a scaly RASHthat may itch or burn. The
skin of the nipple and the areola (the area around
the nipple) may crack and bleed. Because skin
conditions such as atopic DERMATITIS(also called
eczema) and PSORIASIS commonly affect the
breasts, early symptoms are often misdiagnosed as
dermatologic. One subtle difference is that Paget’s
disease of the breast begins in the nipple and
spreads to the areola, whereas dermatologic con-
ditions begin in the areola and extend to the nip-
ple. As Paget’s disease of the breast advances, the
nipple may invert or there may be bloody dis-
charge from the nipple.
The diagnostic path typically includes MAMMO-
GRAM(X-RAYof the breast) and biopsy of the cells
of the nipple and underlying breast tissue. ULTRA-
SOUNDof the breast may reveal tumors within the
breast. Treatment begins with surgery to remove
the cancer, which may be breast-conserving sur-
gery when the cancer remains fairly localized and
simple or radical MASTECTOMYwhen the cancer is
widespread within the breast. RADIATION THERAPY,
HORMONE THERAPY(such as with tamoxifen) when
the underlying cancer is hormone sensitive, and
CHEMOTHERAPYare common adjuvant (follow-up)
treatments.

See also CANCER TREATMENT OPTIONS AND DECI-

SIONS; PAGET’S DISEASE OF THE BONE.

Pap test A screening test for disorders of the

CERVIX, notably CERVICAL INTRAEPITHELIAL NEOPLASIA

(CIN) andCERVICAL CANCER. A Pap test, also called a

Papanicolaou test, is the laboratory examination of

cells swabbed from the cervix during a PELVIC EXAM-

INATION. The test derives its name from the doctor

who developed it. Women over age 18 should have

Pap tests every one to three years, depending on

their health status. A woman who has had a total

HYSTERECTOMY (surgical removal of the UTERUS

including the cervix) for reasons other than cancer

does not need Pap tests unless she has a history of

HUMAN PAPILLOMAVIRUS(HPV). When the hysterec-

tomy was for cancer or was a simple hysterectomy

(removal only of the uterus), the woman needs Pap

tests according to routine recommendations.

See also COLPOSCOPY.

paraphimosis A condition in which the foreskin

retracts onto the shaft of the PENISand will not

return to its normal position to cover the glans

(tip of the penis). Paraphimosis can only occur in

an uncircumcised man. The foreskin swells and

acts as a tourniquet, constricting the flow of BLOOD

and causing the shaft of the penis to engorge

while cutting off the blood supply to the glans.

Paraphimosis requires immediate medical atten-

tion to prevent permanent damage, including GAN-

GRENEthat necessitates AMPUTATION, to the penis.

Treatment for paraphimosis includes measures

to reduce swelling such as ice and compression

dressings to the penis. Injection of hyaluronidase,

an enzyme, often rapidly reduces the swelling

(edema). Once the swelling goes down the doctor

may then gently manipulate the foreskin back

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