Skin disorders that appear in association with internal malignancies are called dermadromes. Bullous pemphigoid (BP), which is a major autoimmune disease of the skin, is considered to be a dermadrome, although there have been conflicting reports. We report a case of BP that preceded the diagnosis of an internal malignancy. Although we could not detect any malignancies on chest, abdominal or pelvic computer tomography on the first hospital admission, intensive screening on the third admission revealed a gallbladder malignancy. Laparoscopic cholecystectomy was performed. Histopathology showed a spindle cell carcinoma of the gallbladder. To the best of our knowledge, this is the first report of a spindle cell carcinoma of the gallbladder in a patient with BP.