Impact of combining photodynamic diagnosis with reflectance confocal microscopy, on tumor margin detection and surgical outcomes in patients with extramammary Paget disease.

Background The recurrence rate of extramammary Paget disease after surgical resection is high due to the lesions' poorly delineated and unclear margins. Aims To evaluate the impact of non-invasive tumour margin detection via photodynamic diagnosis plus reflectance confocal microscopy on the surgical outcomes of patients with extramammary Paget disease. Methods Thirty-six patients with histopathologically confirmed primary extramammary Paget disease between January 2017 and June 2018 were included in this study. The skin lesion margins were preoperatively observed using the naked eye, photodynamic diagnosis, and reflectance confocal microscopy. An incision was made 0.5-2 cm from the outermost non-invasive detection marker line. The incision depth was more significant than the follicle level or the deepest level affected by the tumour in the biopsy specimens. After the skin lesions were removed, a pathological examination of the specimens was conducted to ensure clear margins to prevent tumour recurrence and metastases. Results A total of 166 good-quality tissue sections were selected from 36 patients. The tumour surfaces and deep margins were within the scope of resection. Six patients (6/36, 15.4%) experienced local recurrence 2-12 months postoperatively. One patient (1/36, 2.8%) had lymph node metastasis without local recurrence 36 months postoperatively and died 50 months postoperatively (1/36, 2.8%). Limitations This study is limited by the small patient population, especially the number of patients with mucous membrane involvement. Conclusion Using photodynamic diagnosis plus reflectance confocal microscopy to detect the margins of extramammary Paget disease lesions non-invasively reduces the postoperative tumour recurrence rate and is a valuable guide for tumour treatment.

Utility of photodynamic diagnosis plus reflectance confocal microscopy in detecting the margins of extramammary Paget disease.

BACKGROUND: Due to the clinically poorly delineated unclear margin of extramammary Paget disease, the recurrence rate after surgical resection is high. AIMS: To compare photodynamic diagnosis and photodynamic plus reflectance confocal microscopy diagnosis in determining the tumor margins in patients with extramammary Paget disease. METHODS: Thirty-six patients with histopathologically confirmed primary extramammary Paget disease between January 2017 to June 2018 were included in the study. The skin lesion margins were preoperatively observed by the naked eye and with photodynamic diagnosis and photodynamic diagnosis plus reflectance confocal microscopy and they were compared to the postoperative histopathological examination results. RESULTS: Among the 130 sections taken from 36 patients, 83 sections (63.8%, 83/130) had tumor margins beyond the macroscopic line with a distance of 3.5 ± 3.1mm and a median of 2.7mm. Forty-six sections (35.4%, 46/130) exceeded the photodynamic diagnosis marker line with a distance of 2.1 ± 1.7mm and a median of 1.5mm. Twenty seven sections (20.8%, 27/130) were obtained beyond the photodynamic diagnosis plus reflectance confocal microscopy marker line with a distance of 1.4 ± 1.2mm and a median of 0.9mm. LIMITATIONS: Photodynamic diagnosis and reflectance confocal microscopy detection can be used to observe only the superficial margin of the tumor and not the deep part. Moreover, reflectance confocal microscopy was not used alone as a control. CONCLUSION: In terms of determining the extramammary Paget disease margin invasively, photodynamic diagnosis and photodynamic diagnosis plus reflectance confocal microscopy were found superior to observations made with the naked eye, while photodynamic diagnosis plus reflectance confocal microscopy was superior to photodynamic diagnosis alone.

Diagnosis of subclinical extramammary Paget's disease with a combination of noninvasive photodynamic diagnosis and reflectance confocal microscopy.

Extramammary Paget's disease is a rare skin malignancy, and its diagnosis requires invasive biopsy and histopathological examination. Surgery is the standard treatment for extramammary Paget's disease patients; however, as incision boundaries and the depth of tumor cell infiltration are often unclear, the postoperative recurrence rate is high. We present a case in which we used photodynamic diagnosis in combination with reflectance confocal microscopy before surgery to detect an extramammary Paget's disease lesion that was located 3 cm away from the classical lesion. This secondary lesion exhibited a subclinical presentation, and it was eventually confirmed as an extramammary Paget's disease lesion by pathological examination. During detection using our technique, we delineated the boundaries of the extramammary Paget's disease lesion as a guide for surgical excision. The findings of our case demonstrate that photodynamic diagnosis combined with reflectance confocal microscopy can be used for the noninvasive diagnosis of subclinical extramammary Paget's disease and may be used to guide strategies for planning treatment and preventing relapse.