【Abstract】Giant lymphocyte proliferation disease called paraneoplastic pemphigus is an abnormal lymphoproliferative disorder of unknown etiology, concomitant changes in skin and mucous membranes. Giant lymphocyte proliferation disease rarely occurs in the retroperitoneum. Its clinical features are not special and easily misdiagnosed. Different treatment modalities should be adopted according to their pathological classification. This article summarized its characteristics, diagnosis and treatment strategy, in order to improve the understanding and diagnosis and treatment level of giant lymphocyte hyperplasia