Lichen myxedematosus (LM) is an idiopathic cutaneous mucinosis disorder, and monoclonal gammopathy of undetermined significance (MGUS) is a preneoplastic plasma cell disease with a monoclonal increase in globulin. Patients with LM combined with monoclonal gammopathy are normally diagnosed with scleromyxedema. However, we report a case of generalized papules combined with MGUS in a 78-year-old man who was eventually diagnosed with atypical or intermediate forms of LM because it only involved the skin, and the pathological type was not consistent with scleromyxedema. Few cases of atypical or intermediate forms of LM have been reported, so the course of atypical or intermediate forms of LM is unpredictable. We report the diagnosis and treatment of a case of atypical forms of LM to discuss the current understanding of the disease, hoping to provide a reference for clinical research on this disease.

We report the case of a 47-year-old male patient with pigmentation of the head, face and hands, who was initially diagnosed as having primary adrenal insufficiency (Addison\'s disease). Laboratory testing, imaging and physical examination revealed subclinical hypothyroidism, high circulating prolactin and oestradiol concentrations, gynaecomastia, lymphadenopathy, splenomegaly and weakness of both lower limbs. These findings led us to consider whether a single or multiple diseases were present in this patient. Indeed, Addison\'s disease can represent one aspect of a wider systemic disease. Therefore, we performed further examinations, and found high serum M protein (5.1%) and vascular endothelial growth factor [1005.30 pg/mL (normal range 0 to 142 pg/mL)] concentrations. As a consequence, we diagnosed polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes (POEMS) syndrome. Consequently, when a single disease cannot fully explain the multiple symptoms and signs of one patient, clinicians should consider the possibility of the presence of a wider syndrome and undertake more detailed diagnostic testing.