A 76-year-old Japanese man presented with a 6-year history of a
sore throat. He was treated at several clinics without any improvement before being referred to us. Physical examination revealed widespread erosions and
ulcers from the palate to the larynx. Approximately 25 × 15 mm in size, erosive lesions were present on the retroauricular regions, forearms, and glans penis. Pseudomembranous
conjunctivitis was also observed. The skin biopsy revealed a partial cleft formation below the epidermis, suggesting subepidermal bullous disease. Immuno-serological tests were negative for anti-
desmoglein 1 (Dsg1), anti-Dsg3, anti-BP180, and anti-BP230
antibodies by ELISAs. A whole-body examination revealed
gastric cancer. The possibility of mucous membrane
pemphigoid (
MMP) or paraneoplastic
pemphigus (PNP) was considered. Indirect immunofluorescence using rat bladders showed positive
IgG reactivity with cell surfaces on the transitional epithelia. Immunoblotting using
recombinant proteins of laminin-332 showed both
IgG and
IgA reactivities with laminin-α3, and immunoblotting using normal human epidermal extract showed double-positive reactivities with
envoplakin and periplakin for both
IgG and
IgA antibodies. Based on the clinical and histopathological features and results of various immuno-serological tests, our case was diagnosed as anti-laminin-332-type
MMP with serological findings of PNP. Twenty days after laparoscopic
gastrectomy, treatment with oral
methylprednisolone 32 mg/day was initiated, and mucosal and skin lesions improved.