A case of paraneoplastic autoimmune multiorgan syndrome (PAMS)

Paraneoplastic autoimmune multiorgan syndrome (PAMS) is also known as paraneoplastic pemphigus, and this is a heterogenous autoimmune syndrome involving the skin, mucosa and internal organs and it is caused by autoantibodies related to the underlying neoplasm. Painful stomatitis is the earliest and most constant feature. The cutaneous lesions of this disease are polymorphic. The majority of cases of this syndrome are associated with a lymphoproliferative disorder such as non-Hodgkin lymphoma, chronic lymphocytic leukemia and Castleman disease. A 40-year-old woman presented with a 1-month history of a pruritic erythematous papulomacular rash on the trunk and extremities. She also had a 4-month history of painful oral stomatitis that had failed to respond to steroid therapy. Despite the vigorous treatment, the skin lesions progressed to generalized polymorphic lesions with persistent oral lesions. The histopathologic findings of these lesions revealed polymorphous characteristics according to the clinical features, and they mimicked erythema multiforme, graft-versus-host disease, lichen planus and pemphigus vegetans. Finally, a mass of lymphatic tissue 7.2 cm in diameter and that was diagnosed as Castleman disease was found in her retroperitoneal pelvic cavity. With removal of the lymphatic mass, her skin lesions subsided except for the glossal lesion.