POEMS syndrome (also termed osteosclerotic myeloma, Crow–Fukase syndrome, Takatsuki disease, or PEP syndrome) is a rare paraneoplastic syndrome caused by a clone of aberrant plasma cells. The name POEMS is an acronym for some of the disease's major signs and symptoms (polyneuropathy, organomegaly, endocrinopathy, myeloma protein, and skin changes), as is PEP (polyneuropathy, endocrinopathy, plasma cell dyscrasia).
The signs and symptoms of most neoplasms (excessive, abnormal tissue growths) are due to their mass effects (compression of surrounding tissue by the mass of the growth) caused by the invasion and destruction of tissues by the neoplasms' cells. Signs and symptoms of a cancer causing a paraneoplastic syndrome result from the release of humoral factors such as hormones, cytokines, or immunoglobulins by the syndrome's neoplastic cells and/or the response of the immune system to the neoplasm. Many of the signs and symptoms in POEMS syndrome are due at least in part to the release of an aberrant immunoglobulin, i.e. a myeloma protein, as well as certain cytokines by the malignant plasma cells. Some features have been observed in patients with POEMS syndrome but are not yet certain to form part of the syndrome itself. These include a predisposition to forming blood clots, joint pain, cardiomyopathy (systolic dysfunction), fever, low vitamin B12 levels, and diarrhea.
Diagnosis
The diagnosis of POEMS syndrome is based on meeting its two mandatory criteria, meeting at least one of its 3 other major criteria, and meeting at least one of its 6 minor criteria.
Plasma cell dyscrasia
Plasma cell dyscrasias are a group of monoclonal gammopathies in which normal plasma cells in the bone marrow and soft tissues become altered. POEMS syndrome is often associated with an IgA or IgG lambda limited plasma cell dysfunction. On iliac crest biopsies, patients with POEMS syndrome often have few monoclonal plasma cells. In patients with localized illness, iliac crest biopsies may be normal. Other common findings were megakaryocyte hyperplasia and clustering, as well as unusual megakaryocyte appearances. Atypical plasma cells invade normal marrow in osteosclerotic lesions, causing sclerosis of the bony lamellae. Men frequently experience impotence and gynecomastia. Amenorrhea tends to be common in women.
History
R. S. Crow, working in Bristol, first described the combination of osteosclerotic myeloma, polyneuropathy and various unusual features (such as pigmentation and clubbing) in two patients aged 54 and 67, in 1956.