Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal Protein, and Skin Changes Associated With Castleman Disease: A Common Misdiagnosis.

Castleman disease is a rare lymphoproliferative disorder. Co-presentation with polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes (POEMS syndrome) has been documented in 11-30% of Castleman disease cases. POEMS syndrome is a rare paraneoplastic disorder characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes. Not all features are required to make the diagnosis. We report a case of a woman who presented with a 1-year history of a left-side supraclavicular swelling associated with constitutional symptoms and symmetrical paresthesia of the lower limbs. In addition, she had skin hyperpigmentation, multiple supra and infra-diaphragmatic lymphadenopathies, hepatosplenomegaly and osteosclerotic lesions. Serum immunofixation was positive for immunoglobulin G-kappa gammopathy. A lymph node excisional biopsy was compatible with Castleman disease. The diagnosis of POEMS syndrome associated with Castleman disease was made. Our patient started treatment with a combination of bortezomib, cyclophosphamide, and dexamethasone with clinical and analytical improvement. Current treatment of POEMS syndrome associated with Castleman disease is focused on the management of POEMS syndrome. Early diagnosis requires a high index of suspicion and is crucial to reduce morbidity and mortality. This case report aims to raise awareness about this rare entity.