Long-term follow-up study of clear cell papulosis

Background

Clear cell papulosis (CCP) was described as a new entity in 1987. Since then, only case reports or small case series have appeared in the literature and the long-term outcome of CCP remains unknown.

Objectives

The aim of this study was to review cases of CCP diagnosed at our institution and to investigate their outcome.

Methods

Nineteen patients given a diagnosis of CCP more than 6 years previously were identified. Their medical records and histopathologic findings were reviewed.

Results

With a median follow-up duration of 11.5 years, regression of skin lesions was observed in 85.7% of patients. Persistence of skin lesions 11.5 years after diagnosis was confirmed histopathologically in one case, with a reduction in clear cell density.

Limitations

Retrospective nature of the study is a limitation.

Conclusion

No treatment is necessary for CCP because the skin lesions are asymptomatic and most patients experience at least partial regression.

Key words: clear cell papulosis, clear cells of Toker, extramammary Paget disease, long-term follow-up, milk line

Abbreviations used: CCP, clear cell papulosis, CEA, carcinoembryonic antigen, EMA, epithelial membrane antigen, EMPD, extramammary Paget disease, MPD, mammary Paget disease, PAS, periodic acid–Schiff