A patient with myasthenia gravis, a malignant thymoma, and pemphigus erythematosus was found to have antibodies to the cross striations of skeletal muscle, to the intercellular areas of stratified squamous epithelium, and to nuclei as revealed by indirect immunofluorescence. Somewhat comparable observations have been made in other cases. The concurrence of these rare immunologic derangements point to some common underlying mechanisms.
Beutner EH, Chorzelski TP, Hale WL, Hausmanowa-Petrusewicz I. Autoimmunity in Concurrent Myasthenia Gravis and Pemphigus Erythematosus. JAMA. 1968;203(10):845-849. doi:10.1001/jama.1968.03140100027006