What is POEMS syndrome?
Symptoms
Polyneuropathy
Organomegaly
Endocrinopathy/edema
Monoclonal gammopathy
Skin changes
Other symptoms
Pathophysiology
Diagnosis
Treatment
References
Further reading
'POEMS syndrome' refers to polyneuropathy, organomegaly, endocrinopathy/edema, monoclonal gammopathy, and skin changes. Taken together, these symptoms reflect a paraneoplastic disease that, in rare cases, arises in patients with plasma cell neoplasms.
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What is POEMS syndrome?
A plasma cell neoplasia is a benign or malignant disease defined by the overproduction of plasma cells. The three types of plasma cell neoplasms include monoclonal gammopathy of undetermined significance (MGUS), plasmacytoma, and multiple myeloma.
POEMS syndrome can develop in patients aged 50 or older in extremely rare cases of plasma neoplastic diseases. Notably, men are at a 1.5 times greater risk of POEMS syndrome than women.
Due to the rarity of POEMS syndrome, it is often difficult to recognize. As a result, the incidence of this paraneoplastic syndrome is likely underrepresented, leading to challenges in its management.
Symptoms
As indicated in its name, POEMS syndrome is associated with several distinct signs and symptoms.
Polyneuropathy
Polyneuropathy can cause patients with POEMS syndrome to experience numbness, tingling, and/or weakness in their extremities, particularly in the legs and hands. Patients may also feel burning, tickling, numbness, and/or prickling sensations in the skin.
Polyneuropathy may also cause the patient to experience difficulty breathing.
Organomegaly
POEMS syndrome often leads to spleen, liver, and/or lymph node enlargement.
Endocrinopathy/edema
Endocrinopathy occurs when the endocrine glands produce insufficient or excessive levels of their respective hormones. Thus, this symptom of POEMS syndrome depends on the affected gland/hormone.
Some potential manifestations of endocrinopathy may include hypogonadism, diabetes mellitus, hypothyroidism, and primary adrenal insufficiency. Gynecomastia or impotence may develop among men, whereas women may experience amenorrhea, enlarged breasts, abnormal lactation, and/or galactorrhea.
The 'E' in POEMS syndrome can also refer to edematous tissues. This may arise due to increased fluid in the arms and legs, pericardium, peritoneal cavity, or behind the optic nerve.
Monoclonal gammopathy
Monoclonal gammopathy is the presence of excessive monoclonal (M) proteins in the blood due to the circulation of abnormal plasma cells.
In addition to high M protein levels, monoclonal gammopathy may cause plasmacytomas and/or osteosclerosis.
Skin changes
Several dermatological symptoms are associated with POEMS syndrome, including hyperpigmentation, excessive hair growth, scleroderma, excessive sweating, and clubbed fingernails.
Blue discoloration of extremities, white discoloration of the nails, as well as fat wasting at the temples, may also occur in POEMS syndrome.
Other symptoms
In addition to the hallmark symptoms of POEMS syndrome, several other systemic manifestations of this disorder have been described.
Within the blood, for example, POEMS syndrome may lead to thrombocytosis, arterial and/or venous thrombosis, pulmonary arterial hypertension, and increased red blood cell (RBC) counts.
Aside from its presence due to polyneuropathy, difficulty breathing may also be caused by fluid within the lungs, respiratory insufficiency, or reduced total lung capacity.
Patients with POEMS syndrome may also present with headaches, nausea, weight loss, and fatigue.
What is POEMS?
Pathophysiology
Although the exact cause of POEMS syndrome remains unknown, several mechanisms are believed to contribute to the pathophysiology of this disorder.
Vascular endothelial growth factor (VEGF), produced by malignant plasma cells, is often present at increased levels in POEMS patients. Elevated VEGF levels can increase the permeability of vascular tissues, as well as lead to angiogenesis and the growth of endothelial cells.
Aside from VEGF, other pro-inflammatory cytokines have been implicated in POEMS syndrome, the most notable of which include interleukin 1β (IL-1β), IL-6, and tumor necrosis factor α (TNF-α). These cytokines are often produced at high levels in POEMS syndrome, subsequently increasing inflammation.
Diagnosis
Both polyneuropathy and monoclonal gammopathy must be present for a POEMS diagnosis.
Suspected POEMS syndrome cases should undergo a thorough clinical evaluation consisting of a physical exam, medical history, and laboratory testing.
Furthermore, the treating clinician should examine the patient's eyes, skin, neurological status, and overall organ function.
Increased levels of M-proteins, blood plasma, VEGF, and the aforementioned pro-inflammatory cytokines within the serum may be used to support a POEMS syndrome diagnosis. Radiographic imaging may also detect osteosclerotic lesions.
Treatment
Typically, the treatment for POEMS syndrome is symptomatic. For example, patients with localized osteosclerotic lesions may benefit from radiation treatment and/or surgical removal of the lesion.
Conversely, widespread osteosclerotic lesions may be managed with certain antineoplastic agents to improve associated symptoms in these patients.
In addition to managing extensive osteosclerosis, chemotherapy may eliminate excessive M proteins circulating in the blood of POEMS syndrome patients.
References
- Faizan, U., Sana, M. K., Farooqi, M. S., & Hasmi, H. (2022). Efficacy and Safety of Regimens Used for the Treatment of POEMS Syndrome – A Systematic Review. Clinical Lymphoma Myeloma and Leukemia 22(2); e26-e33. doi:10.1016/j.clml.2021.07.033.
- Plasma Cell Neoplasms (Including Multiple Myeloma) Treatment (PDQ®) – Patient Version [Online]. Available from: https://www.cancer.gov/types/myeloma/patient/myeloma-treatment-pdq.
- POEMS syndrome [Online]. Available from: https://www.mayoclinic.org/diseases-conditions/poems-syndrome/symptoms-causes/syc-20352678.
- POEMS Syndrome [Online]. Available from: https://rarediseases.org/rare-diseases/poems-syndrome/.
- Jurczyszyn, A., Castillo, J. J., Olszewska-Szopa, M., et al. (2022). POEMS Syndrome: Real World Experience in Diagnosis and Systemic Therapy – 108 Patients Multicenter Analysis. Clinical Lymphoma Myeloma and Leukemia 22(5); 297-304. doi:10.1016/j.clml.2021.10.007.
Further reading
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