A case of pemphigus vegetans occurring at an unusual site and followed by gastric cancer

Pemphigus is a rare autoimmune bullous disorder involving skin and mucous membrane. Pemphigus vegetans is a rare variant of pemphigus and accounts for 5% of all pemphigus cases.1 It is typically characterized by vegetating plaques on skin folds and mucous membranes. The folds involved mainly include the axillary, inguinal, perianal, submammary, and umbilical areas. The diagnosis is based on clinical, histopathological, and immunofluorescence studies. We present a case of pemphigus vegetans occurring on the left upper arm in a patient who also developed gastric cancer. A 68-year-old womanwith a history of old stroke was seen at the dermatology clinic complaining of a 3-month history of a gradually enlarging skin lesion on her left upper arm. Neither itching nor painwasnoted. The lesionwas anoval scaly vegetatingerythematous plaque of 3 cm 4 cm (Figure 1). No other cutaneous or mucosal lesions were found. The initial clinical differential diagnosis included deep fungal infection, nontuberculous infection, and Bowen’s disease. A skin biopsy specimen was taken for pathologic study and the specimen was also sent for fungal and mycobacterial cultures. The histopathological examination showed mild parakeratosis, focal erosion, marked acanthosis with intraepidermal abscesses containing acantholytic cells, eosinophils and neutrophils, heavy eosinophilic and neutrophilic exocytosis, marked papillomatosis with congested vessels, and heavy perivascular infiltrates of lymphocytes, plasma cells, and numerous scattered eosinophils, and neutrophils in dermis (Figure 2A and B). No fungi were found in the horny layer by the Periodic acid-Schiff (PAS) stain. Tissue cultures for fungi and mycobacteria were negative. The diagnosis of pemphigus vegetans was confirmed by direct immunofluorescence study, which showed positive stainings of immunoglobulin G (IgG) and 3rd component of complement (C3; Figure 2C and D). She was treated with intramuscular dexamethasone phosphate 5 mg weekly and with topical steroids twice a day. Her skin lesion gradually subsided. However, 1 month after the diagnosis of pemphigus vegetans, she started to suffer from poor appetite and vomiting. She was found to have gastric adenocarcinoma 5 weeks after the diagnosis of pemphigus vegetans and received partial gastrectomy. Her clinical condition deteriorated after the operation and she died of pneumonia 1 month later. Pemphigus vegetans can occur inpeople of all age groups, and the median age of onset is 40–50 years. Two clinical subtypes have been described based on clinical features and courses. Patients with the Neumann type often beginwith flaccid bullae that erode to form secondary hypertrophic papillated plaques and require higher doses of systemic corticosteroids with protracted courses and frequent relapses. The relatively benign Hallopeau type starts as pustules as the primary lesions and followed by vegetations. It requires lower