Two patients with initial diagnoses of oral lichen planus and pemphigus vulgaris presented with refractory oral mucosal blistering. Subsequent positive serology results for paraneoplastic pemphigus led to the discovery of occult intra-abdominal malignancies in both, unicentric Castleman's and non-Hodgkin's lymphoma. The diagnosis of paraneoplastic pemphigus should be considered in patients with recalcitrant oral ulceration, even in the absence of clinical features of malignancy.
Keywords: Castleman's disease; lichen planus; lymphoma; oral ulceration; paraneoplastic pemphigus.
© 2014 Japanese Dermatological Association.