ATYPICAL PEMPHIGUS ASSOCIATED WITH MALIGNANT THYMOMA AND AUTOIMMUNE-RESPONSE RESTRICTED TO 170-KD ANTIGEN - IS IT A VARIANT OF PARANEOPLASTIC PEMPHIGUS

We describe a case of atypical pemphigus associated with malignant thy moma and myasthenia gravis, with clinical features suggestive of pemph igus foliaceus, but with a histological pattern characteristic of pemp higus vulgaris. Direct immunofluorescence revealed intercellular and b asement membrane zone IgG and C3 deposits. The circulating antibodies were of unique specificity, restricted to the 170 kD antigen, as found by immunoprecipitation assay. Our case provides evidence that pemphig us associated with malignancy may have divergent clinical features and immune responses, such as to the 170 kD antigen, one of the character istic polypeptides of paraneoplastic pemphigus (PNP). Thus, this case may present a variant of PNP.