Background: Pemphigus herpetiformis (PH) is a rare clinical entity that combines the clinical features of dermatitis herpetiformis and the immunopathologic features of pemphigus. The target antigen is usually desmoglein 1, with exceptional cases manifesting autoantibodies against desmoglein 3. More recently, it has been found that many patients with PH also demonstrate autoantibodies against desmocollin. The association of PH with a malignant neoplasm is rare.
Observations: We describe a patient with PH and a lung neoplasm. Immunologic studies demonstrated IgG antibodies to desmoglein 3 and to an unknown 178-kDa protein but no antibodies to desmocollin.
Conclusions: The association of PH with a thoracic malignant neoplasm has been reported in only 4 previous cases, and the neoplasm could be responsible for the unusual immunologic profile in the patient described herein. To our knowledge, this is the first report of PH with an associated neoplasm in which only anti-desmoglein 3 antibody was detected.