Hypopigmentation in Extramammary Paget Disease Is an Important Prognostic Factor for High Recurrence Rate and Poor Surgical Outcome

Pathologically Confirmed Subcutaneous Fat and Lymphovascular Invasion of a Hypopigmented Area in Extramammary Paget Disease

Extramammary Paget disease (EMPD) is a rare adenocarcinoma that usually occurs in areas of the body that are rich in apocrine sweat glands. Great depth of tumor invasion is a well-known risk factor for worse prognosis. Paget cells usually are limited to the epidermis, whereas invasive EMPD, which infiltrates the dermis, is relatively rare. It is even rarer for the tumor to spread beyond the dermis. Only 3.1% of patients with EMPD of the penis and scrotum have exhibited infiltration of the subcutaneous fat layer. We report a case of a 62-year-old male with EMPD that invaded the subcutaneous fat layer. He presented with a several-year history of a slowly expanding erythematous plaque with the hypopigmented area on the left penoscrotum. One month before presentation, the patient had undergone punch biopsy at another hospital and diagnosed with EMPD. He had no personal history of urogenital cancers. The patient was treated with Mohs micrographic surgery, and negative margins were achieved after four stages. The histopathologic findings revealed Paget cells scattered throughout the epidermis. At the hypopigmented area, Paget cells extended to the subcutaneous fat layer with lymphovascular invasion. There was no evidence of recurrence at seven months postoperatively. Herein, we describe a case of hypopigmented EMPD that infiltrated the subcutaneous layer, which rarely has been reported in Korea.

Clinical and dermoscopic features of extramammary Paget's disease: A retrospective analysis of 49 cases

BACKGROUND

Extramammary Paget's disease (EMPD) is a rare cutaneous malignancy that can be easily confused with other diseases due to its diverse clinical manifestations, delaying the timing of treatment. Therefore, early diagnosis is extremely important. It has been reported that dermoscopy can be used to evaluate superficial skin tumors.

OBJECTIVE

To investigate the dermoscopic characteristics of EMPD diagnosed by histopathology and to develop a decision tree model that can provide clinicians with a reference to facilitate early diagnosis.

METHODS

All patients were evaluated by dermoscopic and histopathologic examinations. Dermoscopic images were assessed, and a decision tree model was constructed using SPSS (version 25.0).

RESULTS

A total of 49 patients were included in this study. We found that EMPD was most likely to be misdiagnosed when the disease duration was less than 2.5 years. Porcelain-white patches were the only key clinical feature other varying dermoscopic features could not be differentiated from those of EMPD-mimicking diseases. Polymorphic vessels were considered to be significant when the duration of the disease ranged from 0.1 year to 2.5 years. However, when the duration was >2.5 years, present (or absent) glomerular vessels were all considered EMPD.

CONCLUSIONS

Dermoscopy can be used as an auxiliary diagnostic tool for the diagnosis and management of EMPD. The decision tree can guide clinical diagnosis further validation studies are necessary due to the limited number of cases.