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AT-A-GLANCE
Rare complication of malignancy, most commonly non-Hodgkin lymphoma, chronic lymphocytic leukemia, or Castleman disease.
Painful, erosive stomatitis and polymorphous cutaneous lesions that may be blistering and erosive (resembling erythema multiforme), morbilliform, or lichenoid.
Serum autoantibodies directed against plakin proteins that are detected by indirect immunofluorescence against rodent bladder epithelium.
High mortality rate, with death from sepsis, complications of treatment, or bronchiolitis obliterans.
No consistently effective therapy, but some success with the combined use of rituximab, systemic corticosteroids, and other immunosuppressive agents.
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Paraneoplastic pemphigus (PNP) is an autoimmune disorder that is almost always linked to an underlying lymphoproliferative disorder. These features define it (Table 53-1): (a) Painful stomatitis and a polymorphous cutaneous eruption with lesions that may be blistering, lichenoid, or resemble erythema multiforme. (b) Histologic findings that reflect the variability of the cutaneous lesions, showing acantholysis, lichenoid, or interface change. (c) Direct immunofluorescence findings of immunoglobulin (Ig) G and complement deposition in the epidermal intercellular spaces, and, often, granular/linear complement deposition along the epidermal basement membrane zone. (d) Serum autoantibodies that bind to the cell surface of skin and mucosae in a pattern typical of pemphigus, which, in addition, also bind to simple, columnar and transitional epithelia. (e) The serum autoantibodies identify desmogleins 1 and 3, in addition to members of the plakin family of epithelial proteins, such as desmoplakins, envoplakins, and periplakins.1 Non-Hodgkin lymphoma (NHL), chronic lymphocytic leukemia (CLL), and Castleman disease are the neoplasms most commonly associated with PNP. There is no regularly effective treatment. Most patients die from complications of the disease such as pulmonary involvement with respiratory failure.
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The incidence of PNP is unknown, although it is less common than pemphigus vulgaris or foliaceus (see Chap. 52). In an adverse events reporting analysis including 100,000 patients with known NHL and CLL, 12 were found to have PNP.2 Only 3 of the 12 patients were identified by the reporting physician, and the remainder were identified only by retrospective data analysis, suggesting that the majority of cases of PNP are not being properly diagnosed. In this series, the most common misdiagnoses were erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis (TEN), and drug reaction.
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ETIOLOGY AND PATHOGENESIS
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In almost all cases, PNP is associated with a limited number of lymphoproliferative ...