Paraneoplastic Pemphigus with Underlying Castleman's Disorder: A Rare Report with Literature Review.

Paraneoplastic pemphigus (PNP), also known as paraneoplastic autoimmune multisystem syndrome (PAMS), is an autoimmune blistering disorder of the skin associated with various hematological and nonhematological malignancies. In most of the cases, it can be a harbinger of a concealed benign or malignant neoplasm. We report the case of a 23-year-old female patient who presented to the dermatology consult service with a previously known diagnosis of refractory pemphigus vulgaris but she failed to reach remission for her oral and skin lesions on steroid and intravenous immunoglobulin (IVIG). She was later investigated for underlying malignancy as the concern of PNP was raised. She was found to be diagnosed with a pelvic mass which was found to be Castleman's disease. Our patient responded well to surgery and postoperative course of pulsed methylprednisolone and IVIG. Here, we discuss the diagnosis and clinical course of this unique case and strive to create awareness about PNP that can present as a refractory polymorphous blistering dermatological disorder and can hinder the diagnosis and management of patients.