Lichenoid paraneoplastic pemphigus in a patient presenting with follicular lymphoma: a review of the literature.

Paraneoplastic pemphigus (PNP) is a rare, autoimmune, mucocutaneous blistering disease that is almost always associated with a confirmed or occult neoplasm. PNP often presents with characteristic features of intractable stomatitis and polymorphous cutaneous eruptions, including blisters and lichenoid dermatitis caused by humoral and cell-mediated autoimmune reactions. We present the following case of a patient with follicular lymphoma (FL) who developed lichenoid PNP involving the buccal mucosa and lateral tongue. We also summarize the literature, discussing current proposed mechanisms, guidelines, and treatment of this unique disease. While patients can achieve complete remission from their underlying neoplasm, most patients with PNP do not have a good survival time with a 5-year survival rate of only 38%. This case sheds light on an uncommon occurrence, highlights the need for further studies around PNP as it relates to FL, and suggests that T cell immunosuppressive therapy may be effective in treating FL patients with PNP.