Paraneoplastic pemphigus without an underlying neoplasm

We describe a 52-year-old man with paraneoplastic pemphigus (PNP) without any evidence of an underlying neoplasm over an 8-year follow-up period. He had a chronic relapsing vesiculobullous eruption for approximately 7 years (from April 1998 to May 2005). Initially, scattered flaccid vesicles with crusts developed on the face and trunk, which waxed and waned several times. Our patient was diagnosed as having PNP based on immunopathological criteria for PNP, i.e. histopathological, immunoblotting and immunoprecipitation analyses. However, physical and laboratory examinations including serial blood tests with peripheral blood smear, whole-body positron emission tomography/computed tomography and abdominal ultrasound were unable to detect any underlying neoplasm over an 8-year follow-up period.