All of the following skin conditions are considered as skin markers for internal malignancy except
Acanthosis nigricans
Dermatomyositis
Bullous pemphigoid
Pemphigus valgaris
Acanthosis nigricans, brown to grey - black velvety thickening of the skin in flexural areas, is caused by insulin resistance, obesity, drugs and underlying malignancy (esp. of the stomach and large intestine).Dermatomyositis results from an immune-mediated process triggered by various factors such as malignancy ( ovarian carcinoma, nasopharyngeal carcinoma, mycosis fungoides and lymphoproliferative malignancies ), drugs and infectious agents in genetically predisposed individuals. Bullous pemphigoid (BP) is an acquired, autoimmune, sub-epidermal blistering disease. It is also associated with underlying malignancies (SCC,RCC)Reference : page 303,274,283 IADVL's Concise Textbook of Dermatology
Urology