POEMS syndrome

The name is an acronym for its main features: Polyneuropathy, meaning widespread nerve damage; Organomegaly, meaning enlarged organs such as the liver, spleen or lymph nodes; Endocrinopathy, meaning hormone gland problems; a Monoclonal plasma cell disorder; and Skin changes.

The NCI describes it as a rare condition associated with a plasma cell disorder, in which the illness comes from substances the abnormal cells release into the body rather than from the size of the group or where it sits. The clone is typically tiny — under 5% of the plasma cells in the marrow.

The M stands for a monoclonal plasma cell disorder, not for myeloma. And the acronym is not the diagnostic test: the formal criteria require nerve damage and a monoclonal plasma cell disorder together, plus at least one of three other major features, plus at least one of a longer list of minor ones. Swelling of the optic disc, fluid overload and a high platelet count are all real features the acronym leaves out.

One of those major features is worth naming because it explains much of the illness. VEGF is a signalling protein that drives blood-vessel growth and makes vessels leaky. It is markedly raised in most people with this condition, and it is thought to produce the swelling, the enlarged organs and the skin changes, and to contribute to the nerve damage.

It is rare. A nationwide survey of neurology and haematology departments across Japan estimated 392 people with it in the country, a prevalence of 0.3 per 100,000.

A small clonal group of plasma cells arises, almost always making one particular type of light chain, and is associated with very high levels of VEGF. Why the clone arises is not known.

It is not inherited, it is not contagious, and it is not caused by anything a person or their family did.

One structural fact decides the treatment route, and it is worth knowing early: roughly two thirds of people have the abnormal cells in the bone marrow, while the remainder have one to three isolated patches of abnormally dense bone and no clone in the marrow at all. That split, rather than how severe the symptoms are, is what determines which treatment is used.

In the Japanese survey, the median age at onset was 54, with a range from 21 to 84, and about three men for every two women.

The nerve damage is the required feature and usually what brings a person in. It starts as numbness and tingling in the feet and moves upward, symmetrically, followed by weakness — a high-stepping gait, then severe weakness in the lower legs and, as it progresses, the arms. Leg pain is prominent.

Because that pattern looks at first like a commoner immune nerve condition called CIDP, people are frequently treated for that instead. Delays of more than 13 months from the first symptoms are reported as common.

Beyond the nerves and the enlarged organs, people can have fluid building up in the legs, around the lungs or in the abdomen, swelling of the optic disc at the back of the eye, a high platelet count, and problems with the thyroid, adrenal, pituitary, parathyroid, gonadal or pancreatic glands.

Skin changes are common — darkening, thickening, or new small blood vessels visible at the surface.

Mobility loss is very often the dominant day-to-day problem, more than any single organ finding.

The route is decided by imaging and a bone marrow biopsy rather than by symptoms, and there are two routes.

For people with one to three bone lesions and no clone found in the marrow, radiation to the lesion is the preferred first strategy. That is not a lesser option or a fallback — for that group it is the treatment, and reported doses have run from 30 to 54 Gy.

For the roughly two thirds who have the clone in the marrow, radiation alone is less effective and drug treatment aimed at the plasma cells is used instead. For those fit enough, that can include high-dose chemotherapy with an autologous stem cell rescue — the person’s own cells, collected beforehand and given back.

The drugs used include lenalidomide with a steroid. One drug class used widely in myeloma is used cautiously here because it can itself cause nerve damage.

One hazard around the transplant is specific enough to name: an engraftment-type reaction with fevers, rash, diarrhoea, weight gain and breathing symptoms, typically about a week to two weeks after the cells are given back. One review reports it in roughly half of transplants for this condition, far more often than in myeloma. Recognising it promptly is how it is managed.

Where nerve recovery happens, it is slow and partial, following the fall in VEGF over months rather than days. Nothing here should be read as a promise of walking again or a timeframe for it.

The first year is usually a neurology story rather than a cancer story: numbness and tingling in the feet, then leg pain, then weakness and difficulty walking. Many people are treated for a different nerve condition first.

The diagnosis usually arrives only when someone connects the nerve damage to the rest of the picture — a monoclonal protein, a raised VEGF, a dense patch of bone, swelling, darkened skin, an enlarged spleen. It is a diagnosis made by assembling a pattern, which is part of why it takes so long.

Rehabilitation, orthotics and pain management are a large part of care alongside the treatment aimed at the clone, because mobility is often what has been lost.

It is rare enough that most people will be the only case their local team has seen.

For those who have a transplant, there is no donor and no search — but there is still apheresis to collect the cells, high-dose chemotherapy, weeks of very low blood counts, infection risk, transfusion support and a long recovery. "No donor needed" does not mean this is the easy one.

A person diagnosed with POEMS syndrome does not need a matched bone marrow donor and is not waiting for one.

Where a transplant is used here it is autologous — the person’s own cells. Two transplant registries have reported on this condition specifically: 331 autologous transplants recorded across the CIBMTR network between 2008 and 2018, and 127 recorded across Europe between 1997 and 2010. Neither report describes a donor transplant for POEMS syndrome.

And for a third of people the first treatment is radiation to a bone lesion, with no transplant of any kind involved.

The donation these patients do depend on is blood and platelets. Anyone going through high-dose chemotherapy with an autologous rescue spends weeks with very low counts and is commonly transfused.

If this page makes the case for joining a donor registry, it makes it on behalf of other people — those with leukemia, aplastic anemia, or an inherited marrow disorder — and not on behalf of the reader.