Extramammary Paget's disease: extended subclinical growth detected using three-dimensional histology in routine paraffin procedure and course of the disease.

BACKGROUND

Extramammary Paget's disease (EMPD) is a rare tumor of the skin characterized by extended irregular subclinical growth and high recurrence rates after surgery.

OBJECTIVE

To show that, using three-dimensional (3D) histology in surgical excision, the size of the safety margin can be individually determined and locally adjusted to subclinical growth and to evaluate the course of the disease in 33 patients.

METHODS

The clinical records of 33 patients with primary lesions of EMPD were prospectively documented, retrospectively confirmed, and analyzed.

RESULTS

EMPD was found more frequently in women (54.5%). Dermal invasion was found in 21.2%, and regional lymph node metastases were present in one patient; 30.3% of the patients had secondary internal malignancies. In 25 cases examined using 3D histology, a mean surgical margin of 22 mm in asymmetric shape (range 5-65 mm) was achieved, with a recurrence rate of 28%. Surgery with conventional histologic examination had a higher recurrence rate of 62.5% using a mean surgical margin of 19 mm (range 7-40 mm).

CONCLUSIONS

Subclinical spread of EMPD demonstrated using 3D histology with paraffin sectioning can be large. Three-dimensional histology allows individually defined safety margins to be locally adjusted to subclinical growth and gives low recurrence rates. The authors have indicated no significant interest with commercial supporters.