POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder and skin changes) associated with Castleman disease and latent tuberculosis: a diagnostic challenge.

A woman in her 40s of South Asian ethnic origin presented with progressive multisystem disease including chronic distal neuropathy, constitutional decline, lymphadenopathy and serosal effusions. Initial evaluation suggested infection, particularly tuberculosis, causing diagnostic uncertainty. Investigations identified biclonal lambda-restricted paraproteinaemia, generalised lymphadenopathy and mixed axonal demyelinating polyneuropathy. Early lymph node biopsies were inconclusive, but an excision biopsy later confirmed Castleman disease. Bone marrow examination demonstrated a lambda-restricted clonal plasma cell disorder. With neuropathy, monoclonal gammopathy, organomegaly, endocrinopathy, Castleman disease, extravascular volume overload and elevated vascular endothelial growth factor (VEGF), polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder and skin changes (POEMS) syndrome was diagnosed.The patient received daratumumab, bortezomib and dexamethasone, followed by autologous stem cell transplantation, achieving biochemical remission with normalised VEGF, though neuropathy persisted.This case highlights the diagnostic and treatment challenges when associated with Castleman disease and latent tuberculosis. Earlier diagnosis can prevent further neurological damage in POEMS.