A few years ago one of my male patients presented with a groin rash of several months duration

which was unresponsive to various topical antifungals and topical corticosteroids  prescribed by his health care

practitioner.

              The rash was red and scaly encompassing his groin and extending to his scrotal area.There was

associated itching and burning at times. The most important clue here was that the rash had been  chronically

unresponsive to the above measures.

             Consequently,I suspected a condition called extra mammary Paget's disease (EMPD) which

fortunately is a rare  cancerous condition of apocrine gland-bearing sites.

             In addition,two types of EMPD have been described:the primary type thought to arise from a stem

cell within genital skin and not associated with an underlying internal malignancy involving the rectum

and/or other internal body areas.However,the primary type is still a carcinoma of the skin and needs to

be treated.

             Secondary EMPD is the more dangerous type since it is associated with an underlying adnexal

(connected) adenocarcinoma or an underlying visceral(internal) cancer and is the same as mammary

Paget's disease  of the breast(nipple). 

           Fortunately,I referred my patient to a general surgeon for a deep excisional biopsy which confirmed

my clinical diagnosis.The presence of a cellular protein called cytokeratin 20  helps to differentiate

between the primary and secondary types on biopsy.

           In addition,the presence of a gene called HER-2  in the biopsy specimen may indicate a high risk

for lymphatic spread and the need to follow the patient very diligently.

          EMPD most frequently involves the vulva in women,the perianal area,perineum,scrotum,penis and

axillae(armpits). Treatment includes wide surgical excision,radiation therapy,and several topical(external)

agents.