Síndrome POEMS sin enfermedad clonal o proteína M identificable: un diagnóstico a considerar

Abstract

POEMS syndrome is a paraneoplastic disorder associated with clonal proliferation of plasma cells. Diagnosis requires two mandatory criteria (polyneuropathy, plasma cell dyscrasia [M protein]) and a major criterion (Castleman disease, osteosclerotic lesions, elevated VEGF levels) and a minor criterion (organomegaly, volume overload, endocrinopathy, skin changes, papilledema, thrombocytosis/polycythemia). While polyneuropathy is a constant finding, sometimes «M protein» or plasma cell dyscrasia cannot be defined by standard methods. Our objective is to report a case of POEMS without «M protein» and without an identifiable plasma cell disorder. A 36-year-old woman presented with occipital headache, demonstrating ischemic stroke. Physical examination revealed hypopalesthesia, negative deep tendon reflexes, distal paraparesis, and bimalleolar edema. A history of inflammatory polyneuropathy (CIDP) associated with dysesthesia was diagnosed. Treatment was given with prednisone and immunoglobulin. EMG showed demyelinating involvement. CSF, 1 g/dL protein/2 elements. Immunological and endocrinological laboratory results, immunoglobulin dosage, and protein electrophoresis were normal. CT scan of the abdomen showed Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporationhepato-splenomegaly and sacral osteolytic/osteocalcic lesions. Lumbar MRI showed bilateral thickening of the lumbosacral plexuses. PET-CT showed uptake of the sacral lesion. Bone marrow puncture of the lesion and normal bone marrow. Ophthalmological and dermatological studies were normal. VEGF value was 211 pg/ml. A course of bortezomib plus dexamethasone was started, with disappearance of bone uptake on PET-CT and a decrease in VEGF. Although the diagnosis of POEMS is not met, polyneuropathy is a mandatory criterion. The associated clinical findings and response to plasma cell therapies support a diagnosis of POEMS with undetectable M protein. If the diagnosis depends on the detection of M proteins by electrophoresis, up to 25% of reported cases are excluded.