Paraneoplastic pemphigus (PNP)  is an autoimmune disorder stemming from an underlying tumor. It is hypothesized that antigens associated with the tumor trigger an immune response resulting in blistering of the skin and mucous membranes. While patients with malignant and benign tumors are both at risk, malignancy is associated with high mortality rates (near 90%). Current treatment focuses on general wound healing and administering corticosteroids, which has not demonstrated a high success rate. Recent research developments aim to treat the underlying tumor in order to alleviate the symptoms of PNP. Signs and symptoms
While the presence of lesions is the denominator among patients with PNP, the characteristics of the lesions differ. The five clinical presentations of lesions associated with PNP include:

"Pemphigus-like": Flaccid blister (discrete), crusts over the raw exuding skin lesions
"Pemphigoid-like": Tense blister(s) on brick red erythema
"Erythema multiforme-like": Severe polymorphic skin and/or mucous membrane lesions
"Graft-vs.-host disease-like": Widespread lichenoid eruption with severe mucous membrane involvement
"Lichen planus-like": Small red flat-topped scaly papulesIt is most common that mucous membrane lesions of the oral cavity are presented first. They can involve the oropharynx, nasopharynx, tongue, and vermilion (red portion) of the lips. They are also known to develop in the conjunctiva of the eye, anogenital (perineum) region, and esophagus. Cutaneous lesions tend to follow the onset of mucosal lesions. The blisters often erupt in waves, usually affecting the upper trunk, head, neck, and proximal extremities. Pemphigoid-like lesions are seen more often on the extremities.
B cell infection with EBV is latent, and the virus does not undergo replication. These latently infected B cells can then go on to produce proteins that function to promote cellular growth through modification of normal signaling pathways. EBV promotes the development of malignant B cells via proteins that limit apoptosis in cells that had the c-myc translocation. Apoptosis is limited by EBV through various means such as the EBNA-1 protein, BHF1 protein, EBER transcripts, vIL-10 gene, BZLF1, and LMP1. Malaria has been found to cause genomic instability in endemic Burkitt lymphoma. Malaria can lead to the reactivation of latent EBV and also MYC translocations via activation of the toll-like receptor 9. Malaria also promotes B-cell proliferation by altering the regular immune response. The immune system targets antigens (e.g., EBNA2 and LMP-1) and eliminates most B cells infected with EBV. Downregulation of antigens targeted by the immune system leads to the development of persistent B cells. These B cells can then undergo further mutations (e.g., c-myc translocation) that promote cancer development. Immunology
Burkitt Lymphoma cells express HLA class I molecules normally, as well as some HLA class II complexes; however, CD4+ T cells are not properly activated. Burkitt lymphoma cells only express EBNA 1, a poorly antigenic EBV-associated antigen, that is able to escape HLA class I presentation, thus evades an immune response. EBNA 1 can be presented via HLA class II molecules, however HLA Class II pathway is unable to activate the CD4+ T cells.