POEMS syndrome is a rare systemic disorder involving polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes. The article describes the case of a patient aged around 50 years with progressive numbness and weakness of the limbs, hyperpigmentation of the skin, edema of the lower limbs, hypothyroidism and significant hypertriglyceridemia. Repeated serum and bone marrow examinations did not reveal a monoclonal protein. Imaging and pathologic examination of the sacroiliac region showed multiple solitary plasmacytomas with lambda light chain restriction, confirming the diagnosis of POEMS syndrome without detectable M-protein. Significant clinical improvement occurred after bortezomib-based chemotherapy. The case emphasizes that POEMS syndrome should be considered even without a monoclonal protein in the serum or bone marrow, especially in severe hypertriglyceridemia and multisystem damage.