[Clinicopathological features of extramammary Paget's disease: a report of 75 cases]

To evaluate the clinicopathological features of extramammary Paget's disease.

Statistical analyses were performed for the clinicopathological features for 75 cases of extramammary Paget's disease from 2004 to 2013.

Extramammary Paget's disease exhibited a male predominance (5.25:1). The mean age of onset was (64.23 ± 12.02) years. Single lesion accounted for 92.0% (69/75) and most of them were located in genital area. Pruritus occurred in 61.6% (45/73) patients. Invasive extramammary Paget's disease accounted for 22.7% (17/75). The concordance between clinical and pathological diagnoses was 85.3% (64/75). Among 11 misdiagnosed cases, 7 cases were misdiagnosed as eczema. Comparing Paget cells located in epithelium of adnexa or dermis and those confined to epidermis, significant differences existed in age of onset, course, recurrence rate (all P<0.05), but not in lesion size. Among 67.1% (47/70) of patients undergoing Mohs surgery, 38.3% (18/47) had a complete one-time resection while 61.7% (29/47) required more than twice for thorough resection. The 5-year recurrence rate was 25.0%. The postoperative 5-year recurrence rate of Mohs micrographic surgery (MMS) was 18.0% and the rate of non-MMS 36.5%. From 2011 to 2013, 3 recurrent cases had no radiotherapy. However another 15 cases on radiotherapy were non-recurrent.

With a slow progression, extramammary Paget's disease is more common among elder males. Recurrence rate is associated with the degree of invasion. Thus an early diagnosis is essential. Due to obvious differences between gross and pathological boundaries, Mohs surgery may help to determine the margin. Meanwhile, adding radiotherapy reduces the recurrence rate.