Characterizing POEMS Syndrome with 18F-FDG PET/CT

Paraneoplastic neuropathies and peripheral nerve hyperexcitability disorders

Peripheral neuropathy is a common referral for patients to the neurologic clinics. Paraneoplastic neuropathies account for a small but high morbidity and mortality subgroup. Symptoms include weakness, sensory loss, sweating irregularity, blood pressure instability, severe constipation, and neuropathic pain. Neuropathy is the first presenting symptom of malignancy among many patients. The molecular and cellular oncogenic immune targets reside within cell bodies, axons, cytoplasms, or surface membranes of neural tissues. A more favorable immune treatment outcome occurs in those where the targets reside on the cell surface. Patients with antibodies binding cell surface antigens commonly have neural hyperexcitability with pain, cramps, fasciculations, and hyperhidrotic attacks (CASPR2, LGI1, and others). The antigenic targets are also commonly expressed in the central nervous system, with presenting symptoms being myelopathy, encephalopathy, and seizures with neuropathy, often masked. Pain and autonomic components typically relate to small nerve fiber involvement (nociceptive, adrenergic, enteric, and sudomotor), sometimes without nerve fiber loss but rather hyperexcitability. The specific antibodies discovered help direct cancer investigations. Among the primary axonal paraneoplastic neuropathies, pathognomonic clinical features do not exist, and testing for multiple antibodies simultaneously provides the best sensitivity in testing (AGNA1-SOX1; amphiphysin; ANNA-1-HU; ANNA-3-DACH1; CASPR2; CRMP5; LGI1; PCA2-MAP1B, and others). Performing confirmatory antibody testing using adjunct methods improves specificity. Antibody-mediated demyelinating paraneoplastic neuropathies are limited to MAG-IgM (IgM-MGUS, Waldenström's, and myeloma), with the others associated with cytokine elevations (VEGF, IL6) caused by osteosclerotic myeloma, plasmacytoma (POEMS), and rarely angiofollicular lymphoma (Castleman's). Paraneoplastic disorders have clinical overlap with other idiopathic antibody disorders, including IgG4 demyelinating nodopathies (NF155 and Contactin-1). This review summarizes the paraneoplastic neuropathies, including those with peripheral nerve hyperexcitability.

POEMS syndrome: Update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

POEMS syndrome is a life-threatening condition due to an underlying plasma cell neoplasm. The major criteria for the syndrome are polyradiculoneuropathy, clonal plasma cell disorder, sclerotic bone lesions, elevated vascular endothelial growth factor, and the presence of Castleman disease. Minor features include organomegaly, endocrinopathy, characteristic skin changes, papilledema, extravascular volume overload, and thrombocytosis.

DIAGNOSIS

The diagnosis of POEMS syndrome is made with three of the major criteria, two of which must include polyradiculoneuropathy and clonal plasma cell disorder, and at least one of the minor criteria.

RISK STRATIFICATION

Because the pathogenesis of the syndrome is not well understood, risk stratification is limited to clinical phenotype rather than specific molecular markers. Risk factors include low serum albumin, age, pleural effusion, pulmonary hypertension, and reduced estimated glomerular filtration rate.

RISK-ADAPTED THERAPY

For those patients with a dominant plasmacytoma, first-line therapy is irradiation. Patients with diffuse sclerotic lesions or disseminated bone marrow involvement should receive systemic therapy. Corticosteroids are temporizing, but alkylators and lenalidomide are the mainstays of treatment, the former either in the form of low-dose conventional therapy or as high-dose conditioning for stem cell transplantation. Thalidomide and bortezomib also have activity, but their benefit needs to be weighed against their risk of exacerbating the peripheral neuropathy. Daratumumab combinations also appear promising based on case series. Prompt recognition and institution of both supportive care measures and therapy directed against the plasma cell result in the best outcomes.

Pulmonary manifestations of POEM syndrome: a retrospective analysis of 282 cases

BACKGROUND

Polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome is a rare multisystemic clonal plasma cell disorder. Pulmonary involvement is frequently found in patients with POEMS syndrome, manifesting various clinical features. Therefore, to improve diagnostic accuracy and provide treatment strategies, a comprehensive analysis of pulmonary manifestations of POEMS syndrome is needed.

METHODS

This retrospective study included patients with POEMS syndrome at Peking Union Medical College Hospital, a major referral medical center in China, between June 1, 2013, and June 1, 2023. Demographic data, laboratory findings, pulmonary function test results, echocardiograms, and chest imaging data were extracted. Continuous variables were compared using the t-test or Mann-Whitney method. Pearson's chi-square test or Fisher's exact test was conducted to compare categorical data.

RESULTS

Overall, 282 individuals diagnosed with POEMS syndrome were included in this study, of which 56% were male with an average age of 48.7 years. Respiratory symptoms were found in 40.1% of the patients, with dyspnea as the most common symptom (34.4%). Chest computed tomography and echocardiography findings showed that 56.4% of patients exhibited pleural effusion, 62.8% displayed mediastinal or hilar lymphadenopathy, 46.5% presented pleural thickening, 27.3% demonstrated bone lesions of the ribs or thoracic vertebra, 7.8% showed lung interstitial abnormalities, and 35.5% had pulmonary hypertension. Decreased diffuse capacity and restrictive ventilatory patterns were identified in 85.2% (115 cases) and 47.4% (64 cases) of patients, respectively. Patients with respiratory symptoms exhibited higher declined lung function measures than those having no respiratory symptoms. High-risk patients with poor prognosis showed more pulmonary function abnormalities.

CONCLUSION

Abnormalities in pulmonary manifestations constitute the significant features of POEMS syndrome. Several patients with POEMS syndrome presented with respiratory symptoms at the initial evaluation. These findings underscore the importance of early identification and accurate diagnosis of POEMS syndrome by clinicians, particularly in cases involving lung and multisystem.

Chronic Inflammatory Demyelinating Polyradiculoneuropathy as a Presentation of Plasmacytoma

Polyneuropathy, organomegaly, endocrinopathy, M protein elevation, and skin changes (POEMS) syndrome is one of the rare paraneoplastic disorders of the multiorgan association whose initialism describes the principal clinical features as polyneuropathy, organomegaly, endocrinopathy, M-protein elevation, and skin changes caused by an underlying plasma cell disorder, one of the major diagnostic criteria for which is the presence of an osseous lesion. We present a case of POEMS syndrome with nearly all signs and symptoms on clinical and hematological examinations, which was further investigated with MRI of the whole spine and 18F-fluorodeoxyglucose positron emission tomography/computed tomography scan, as the latter is a very useful imaging modality for evaluation of any paraneoplastic syndromes, including myeloproliferative disorders such as plasmacytoma or multiple myeloma, and lymphoproliferative or other malignancies.

Imaging of Castleman Disease

Castleman disease (CD) is a group of rare and complex lymphoproliferative disorders that can manifest in two general forms: unicentric CD (UCD) and multicentric CD (MCD). These two forms differ in clinical manifestation, imaging appearances, treatment options, and prognosis. UCD typically manifests as a solitary enlarging mass that is discovered incidentally or after development of compression-type symptoms. MCD usually manifests acutely with systemic symptoms including fever and weight loss. As a whole, CD involves lymph nodes throughout the chest, neck, abdomen, pelvis, and axilla and can have a wide variety of imaging appearances. Most commonly, lymph nodes or masses in UCD occur in the chest, classically with well-defined borders, hyperenhancement, and possible characteristic patterns of calcification and/or feeding vessels. Lymph nodes affected by MCD, while also hyperenhancing, tend to involve multiple nodal chains and manifest alongside anasarca or hepatosplenomegaly. The polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, and skin changes (POEMS) subtype of MCD may demonstrate lytic or sclerotic osseous lesions in addition to features typical of MCD. Since a diagnosis of CD based solely on imaging findings is often not possible, pathologic confirmation with core needle biopsy and/or surgical excision is necessary. Nevertheless, imaging plays a crucial role in supporting the diagnosis of CD, guiding appropriate regions for biopsy, and excluding other potential causes or mimics of disease. CT is frequently the initial imaging technique used in evaluating potential CD. MRI and PET play important roles in thoroughly evaluating the disease and determining its extent, especially the MCD form. Complete surgical excision is typically curative for UCD. MCD usually requires systemic therapy. ^©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

FDG PET-MRI evaluation of synchronous gallbladder adenocarcinoma and POEMS syndrome

POEMS syndrome is a rare paraneoplastic syndrome associated with a plasma cell proliferative disorder. Gallbladder adenocarcinoma is a rare malignancy, with no association with POEMS syndrome. The plasma cell dyscrasia is routinely evaluated with advanced hybrid imaging to assess both anatomic and functional components. We present a case of a 59-year-old female with a known diagnosis of POEMS syndrome who underwent a whole-body restaging evaluation with hybrid positron emission tomography (PET) and magnetic resonance imaging (MR) to restage her plasma cell dyscrasia. She also had a prior diagnosis of gallbladder adenocarcinoma. Our case focuses on the value of PET/MR in this scenario as well as a rare case of osseous metastasis from gallbladder carcinoma.

Update on the POEMS syndrome

POEMS syndrome is an acronym for polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes. It is a rare paraneoplastic disorder related to plasma cell neoplasm. However, its pathophysiology has not yet been clearly elucidated. The production of pro-inflammatory cytokines is thought to play an important role in the pathogenesis of POEMS syndrome. Vascular endothelial growth factor level reflects disease activity, which is helpful for the diagnosis and evaluation of treatment response. Conventional agents such as corticosteroids and melphalan are effective and safe combination regimens. Autologous hematopoietic stem cell transplantation is another option for high-risk transplant-eligible patients. Radiotherapy is effective in patients with localized lesions. The anti-myeloma agents lenalidomide, thalidomide, and bortezomib have shown good treatment outcomes for POEMS syndrome; however, large-scale studies with long-term follow-up are required. Early identification and active treatment can improve the outcomes of POEMS syndrome patients.

A case of systemic mastocytosis mimicking POEMS syndrome: A case report

RATIONALE

POEMS (polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes) syndrome is a rare and complicated disease related to multiple organs and systems. Here, we report a case of systemic mastocytosis (SM) that was misdiagnosed as a POEMS syndrome.

PATIENT CONCERNS

A 42-year-old man presented with skin changes, diarrhea, and limb numbness.

DIAGNOSES

Positron emission tomography/computed tomography revealed extravascular volume overload, organomegaly, lymphadenopathy, and bone lesions with mixed lesions of osteosclerosis and osteolysis. Therefore, POEMS syndrome was suspected. Further histopathological and immunohistochemical examination of the bone marrow, lymph nodes, and gastric mucosa suggested a diagnosis of mastocytosis. The c-Kit D816V mutation confirmed the diagnosis of SM.

INTERVENTIONS

The patient received the treatment of pegylated interferon-alpha weekly and glucocorticoid daily.

OUTCOMES

The symptoms relieved significantly.

LESSONS

There are many similar features between POEMS syndrome and SM, probably leading to misdiagnosis. This study analyzed the different points between them which can provide help for differentiation.

Multiple Myeloma Presenting as Disseminated Osteoblastic Lesions With Intense 18F-FDG Uptake on PET/CT

ABSTRACT

A 42-year-old woman presented with numbness and weakness in the lower limbs. The radiograph, MRI, and 99mTc-MDP bone scintigraphy revealed multiple bone lesions. The lesions were sclerotic on radiograph. Subsequent 18F-FDG PET/CT showed the lesions were disseminated and had intense 18F-FDG uptake. Monoclonal lambda plasmacytoma was confirmed after CT-guided biopsy of the third lumbar vertebral lesion. The laboratory data also showed a monoclonal immunoglobulin G lambda protein in serum and urine immunofixation. The patient was diagnosed as multiple myeloma finally. Multiple myeloma should be in the differential diagnosis scope of multiple osteoblastic lesions with intense 18F-FDG uptake on PET/CT.

POEMS syndrome: 2021 Update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

POEMS syndrome is a paraneoplastic syndrome due to an underlying plasma cell neoplasm. The major criteria for the syndrome are polyradiculoneuropathy, clonal plasma cell disorder (PCD), sclerotic bone lesions, elevated vascular endothelial growth factor, and the presence of Castleman disease. Minor features include organomegaly, endocrinopathy, characteristic skin changes, papilledema, extravascular volume overload, and thrombocytosis.

DIAGNOSIS

The diagnosis of POEMS syndrome is made with three of the major criteria, two of which must include polyradiculoneuropathy and clonal plasma cell disorder, and at least one of the minor criteria.

RISK STRATIFICATION

Because the pathogenesis of the syndrome is not well understood, risk stratification is limited to clinical phenotype rather than specific molecular markers. Risk factors include low serum albumin, age, pleural effusion, pulmonary hypertension, and reduced eGFR.

RISK-ADAPTED THERAPY

For those patients with a dominant plasmacytoma, first line therapy is irradiation. Patients with diffuse sclerotic lesions or disseminated bone marrow involvement and for those who have progression of their disease 3-6 months after completing radiation therapy should receive systemic therapy. Corticosteroids are temporizing, but alkylators are the mainstay of treatment, either in the form of low dose conventional therapy or high dose with stem cell transplantation. Lenalidomide shows promise with manageable toxicity. Thalidomide and bortezomib also have activity, but their benefit needs to be weighed against their risk of exacerbating the peripheral neuropathy. Prompt recognition and institution of both supportive care measures and therapy directed against the plasma cell result in the best outcomes.

[POEMS syndrome: Diagnosis, stratification, treatments]

POEMS syndrome is a rare form of B-cell dyscrasia with multiple clinical signs including the acronym for polyneuropathy, organomegaly, endocrinopathy, M-protein and skin changes. It is a paraneoplastic syndrome due to an underlying plasma cell disorder belonging to the monoclonal gammopathies of clinical significance (MGCS). The major criteria for this syndrome are polyradiculoneuropathy, clonal plasma cell disorder (PCD), sclerotic bone lesions, elevated vascular endothelial growth factor (VEGF), and the presence of Castleman's disease. Minor features include organomegaly, endocrinopathy, skin changes, papilledema, extravascular volume over-load, and thrombocytosis. The diagnosis of POEMS syndrome requires three of the major criteria, two of which must include polyradiculoneuropathy and clonal PCD, and at least one of the minor criteria. VEGF plays a major role in the disease although anti-VEGF treatments have been disappointing. Risk stratification is based on clinical phenotype rather than specific molecular markers. Depending on bone marrow involvement and the number of sclerotic bone lesions, first line therapy should be irradiation or systemic therapy. For patients with a dominant sclerotic plasmacytoma, first line therapy is irradiation. Patients with diffuse sclerotic lesions or disseminated bone marrow involvement and for those who have progression of their disease 3 to 6 months after completing irradiation therapy should receive antiplasma cell systemic therapy, the most effective being high dose chemotherapy with autologous stem cell transplantation. Lenalidomide seems to have a high efficacy with manageable toxicity. Thalidomide and proteasome inhibitors like bortezomib are also effective, but their benefit needs to be weighed against their risk of exacerbating the peripheral neuropathy.

Posttreated POEMS Syndrome With Concurrent Follicular Lymphoma Revealed by 18F-FDG and 68Ga-Pentixafor PET/CT

A 59-year-old man with history of POEMS syndrome was found with a painless mass in the right neck for 9 months. In F-FDG and Ga-pentixafor PET/CT, there were multiple neck nodes and left inguinal nodes that showed intense F-FDG and Ga-pentixafor uptake. In addition, osteoblastic bone lesions with mild F-FDG and Ga-pentixafor uptake were noted in the pelvis, which was consistent with posttreated osseous involvement of POEMS syndrome. However, considering lymphoadenopathy with such intense F-FDG uptake is not usually seen in POEMS syndrome, the patient underwent biopsy of the right cervical nodes. The histopathology with immunohistochemistry confirmed follicular lymphoma.

POEMS syndrome: a unique presentation and a diagnostic challenge

We present the case of a previously well, 70-year-old lady who presented with gait deterioration and a clinicoradiological picture of myositis with T2-enhancement on MRI of the distal lower limb muscles. A muscle biopsy pointed towards neurogenic amyotrophy and a mixed demyelinating and axonal sensorimotor polyneuropathy was confirmed on nerve conduction studies. This was initially thought to be secondary to a myeloproliferative disorder but a positron emission tomography scan showed uptake in the left hip which corresponded to what was previously reported as a subchondral cyst on CT. A biopsy showed this to be a plasmacytoma in the context of a normal serum protein electrophoresis and a polyclonal increase in light chains on serum-free light chain estimation. The patient was started on treatment 6 months after the presentation for a diagnosis of POEMS syndrome, by which time, the patient had become bed-bound and fully dependent.

POEMS Syndrome: 2019 Update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes (POEMS) syndrome is a paraneoplastic syndrome due to an underlying plasma cell neoplasm. The major criteria for the syndrome are polyradiculoneuropathy, clonal plasma cell disorder (PCD), sclerotic bone lesions, elevated vascular endothelial growth factor, and the presence of Castleman disease. Minor features include organomegaly, endocrinopathy, characteristic skin changes, papilledema, extravascular volume overload, and thrombocytosis. Diagnoses are often delayed because the syndrome is rare and can be mistaken for other neurologic disorders, most commonly chronic inflammatory demyelinating polyradiculoneuropathy. POEMS syndrome should be distinguished from the Castleman disease variant of POEMS syndrome, which has no clonal PCD and typically little to no peripheral neuropathy but has several of the minor diagnostic criteria for POEMS syndrome.

DIAGNOSIS

The diagnosis of POEMS syndrome is made with three of the major criteria, two of which must include polyradiculoneuropathy and clonal PCD, and at least one of the minor criteria.

RISK STRATIFICATION

Because the pathogenesis of the syndrome is not well understood, risk stratification is limited to clinical phenotype rather than specific molecular markers. Risk factors include low serum albumin, age, pleural effusion, pulmonary hypertension, and reduced eGFR.

RISK-ADAPTED THERAPY

For those patients with a dominant sclerotic plasmacytoma, first line therapy is irradiation. Patients with diffuse sclerotic lesions or disseminated bone marrow involvement and for those who have progression of their disease 3 to 6 months after completing radiation therapy should receive systemic therapy. Corticosteroids are temporizing, but alkylators are the mainstay of treatment, either in the form of low dose conventional therapy or high dose with stem cell transplantation. Lenalidomide shows promise with manageable toxicity. Thalidomide and bortezomib also have activity, but their benefit needs to be weighed against their risk of exacerbating the peripheral neuropathy. Prompt recognition and institution of both supportive care measures and therapy directed against the plasma cell result in the best outcomes.

Positron Emission Tomography-Computed Tomography in a Case of POEMS Syndrome

The POEMS syndrome is a rare and multisystemic disease characterized by the presence of polyneuropathy, organomegaly, endocrinopathy, presence of M protein, and alterations in the skin. The existence of bone lesions is frequent, being generally blastic or mixed and rarely lytic. We present the case of a 54-year-old male patient diagnosed with POEMS syndrome, with atypical presence of lytic lesions, who was referred for an 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) study for initial staging of the process. There were several hypermetabolic foci coinciding with bone lesions, reaching a maximum standardized uptake value of 15 at the level of the right iliac bone with associated soft-tissue mass. PET-CT is an adequate tool for evaluation, diagnosis, and monitoring of the pathology. The scan allows the detection and selection for its biopsy of bone lesions and lymphadenopathies.

POEMS syndrome: clinical update

POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes) is a rare paraneoplastic syndrome, caused by a plasma cell proliferative disorder, which is most commonly lambda restricted. The neurological hallmark, which forms one of the mandatory criteria for diagnosis, is a subacute onset demyelinating neuropathy, which can be rapidly disabling and painful. A number of multi-system features are also characteristic of this disorder, and certainly not restricted to those included in its acronym, which though limited, remains a useful and memorable name, helping distinguish POEMS syndrome from other paraproteinaemic neuropathies. The discovery of vascular endothelial growth factor (VEGF) in association with POEMS syndrome has been extremely useful in aiding clinical diagnosis, and monitoring response to treatment, as well as helping understand the underlying mechanism of disease. Interestingly, however, treatment targeting VEGF has been disappointing, suggesting other disease mechanisms or inflammatory processes are also important. Current understanding of the pathogenesis of POEMS syndrome is outlined in detail in the accompanying article by Cerri et al. Here, we review the clinical features of POEMS syndrome, differential diagnosis and available treatment options, based on current literature.

A prospective phase II study of low dose lenalidomide plus dexamethasone in patients with newly diagnosed polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome

Polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome is a rare plasma dyscrasia without standard treatment. This phase II prospective trial evaluates the safety and response of 12 cycles of low dose lenalidomide (10 mg) plus dexamethasone (Rdex) in patients with newly diagnosed POEMS syndrome. Forty-one patients (28 men) were enrolled and the median age at diagnosis was 49 years (range, 21-70 years). Twenty-one patients (46%) achieved complete hematologic response and the neurologic response rate was 95%. The median serum vascular endothelial growth factor (VEGF) declined from 5155 pg/mL (range, 534-14 328 pg/mL) to 832 pg/mL (95-6254 pg/mL) after therapy. The overall VEGF response rate was 83%, and the median time to response was 2 months, with a mean VEGF reduction of 43% at the first month. In terms of clinical response, Rdex substantially relieved extravascular volume overload, organomegaly, and pulmonary hypertension. No treatment-related deaths occurred and no patients suffered from lenalidomide-related grade 3 or above adverse events. After a median follow-up of 34 months, median overall survival (OS) and progression-free survival (PFS) were not reached, with an estimated 3-year OS and PFS of 90% and 75%, respectively. In conclusion, Rdex was active with high hematologic, VEGF and organ response rate and well tolerated for patients with newly diagnosed POEMS syndrome. This trial was registered at www.clinicaltrials.gov as #NCT01816620.

The Peripheral Neuropathies of POEMS Syndrome and Castleman Disease

Polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, skin changes (POEMS) syndrome is a rare paraneoplastic disorder. The polyneuropathy can be the presenting symptom and is typically a painful, motor-predominant polyradiculoneuropathy often mimicking chronic inflammatory demyelinating polyradiculoneuropathy. The presence of a lambda monoclonal protein, elevated vascular endothelial growth factor, systemic features, and treatment resistance are clues to the diagnosis. Castleman disease (CD) is seen in a subset of these patients, and when present the neuropathy is similar but less severe. In contrast, in those patients with purely CD, the neuropathy is often a mild, painless distal sensory neuropathy.

POEMS SYNDROME: an Update

POEMS syndrome is a rare, chronic and disabling condition. The causes of this condition remain unknown; however, chronic overproduction of proinflammatory cytokines appears to be a major contributor. Early diagnosis is essential to start treatment before the clinical state of the patient becomes compromised. A complete evaluation of the disease at its onset is critical to the treatment decision. In localized disease, curative doses of radiation (50 Gy) is the recommended therapy. On the other hand, patients with disseminated disease should be given systemic therapy. Treatment-related morbidity can be minimized by an efficient induction therapy that modifies the cytokine status, improving clinical condition and control disease severity before mobilization and transplantation. Patients not suitable for hematopoietic stem cell transplantation (HSCT) are usually treated with alkylator-based therapy. Novel agents may also offer benefits to patients with a poor performance status or renal dysfunction, and induce transplantation eligibility. Given the biological characteristics of POEMS, immunomodulatory effects and the absence of neurotoxicity, lenalidomide appears to be an effective therapy for the treatment of POEMS, both as short induction therapy before PBSCT and in non-transplant eligible patients, as it showed high response rate and durable responses. At present, however, guidelines for the diagnosis and treatment of POEMS are not available and appear advocated.

POEMS syndrome: 2017 Update on diagnosis, risk stratification, and management

DISEASE OVERVIEW

POEMS syndrome is a paraneoplastic syndrome due to an underlying plasma cell neoplasm. The major criteria for the syndrome are polyradiculoneuropathy, clonal plasma cell disorder (PCD), sclerotic bone lesions, elevated vascular endothelial growth factor, and the presence of Castleman disease. Minor features include organomegaly, endocrinopathy, characteristic skin changes, papilledema, extravascular volume overload, and thrombocytosis. Diagnoses are often delayed because the syndrome is rare and can be mistaken for other neurologic disorders, most commonly chronic inflammatory demyelinating polyradiculoneuropathy. POEMS syndrome should be distinguished from the Castleman disease variant of POEMS syndrome, which has no clonal PCD and typically little to no peripheral neuropathy but has several of the minor diagnostic criteria for POEMS syndrome.

DIAGNOSIS

The diagnosis of POEMS syndrome is made with 3 of the major criteria, two of which must include polyradiculoneuropathy and clonal plasma cell disorder, and at least one of the minor criteria.

RISK STRATIFICATION

Because the pathogenesis of the syndrome is not well understood, risk stratification is limited to clinical phenotype rather than specific molecular markers. The number of clinical criteria is not prognostic, but the extent of the plasma cell disorder is. Those patients with an iliac crest bone marrow biopsy that does not reveal a plasma cell clone are candidates for local radiation therapy; those with a more extensive or disseminated clone will be candidates for systemic therapy RISK-ADAPTED THERAPY: For those patients with a dominant sclerotic plasmacytoma, first-line therapy is irradiation. Patients with diffuse sclerotic lesions or disseminated bone marrow involvement and for those who have progression of their disease 3-6 months after completing radiation therapy should receive systemic therapy. Corticosteroids are temporizing, but alkylators are the mainstay of treatment, either in the form of low-dose conventional therapy or high dose with stem cell transplantation. Lenalidomide shows promise with manageable toxicity. Thalidomide and bortezomib also have activity, but their benefit needs to be weighed against their risk of exacerbating the peripheral neuropathy. The benefit of anti-VEGF antibodies is conflicting. Prompt recognition and institution of both supportive care measures and therapy directed against the plasma cell result in the best outcomes.

Osteolytic-variant POEMS syndrome: an uncommon presentation of "osteosclerotic" myeloma

Polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes (POEMS) syndrome, a form of osteosclerotic myeloma, is a multisystem disease related to a monoclonal plasma cell proliferative disorder. Osseous lesions are most commonly sclerotic on radiographs and computed tomography (CT), demonstrate low T1 and T2 signal intensity on magnetic resonance imaging (MRI), and have variable degrees of avidity on positon emission tomography (PET) imaging using 18-fluorodeoxyglucose (¹⁸F-FDG). We present three cases of POEMS syndrome manifesting as osteolytic lesions with indolent features, including well-defined thin sclerotic rims, no cortical disruption or periosteal reaction, no associated soft-tissue mass, and a periarticular location, all features that could lead to misinterpretation as benign bone lesions. We also report increased T1 signal and diffuse solid enhancement of these lesions on MRI, features previously unreported. POEMS syndrome should not be discounted as a diagnostic consideration in the setting of osteolytic lesions with non-aggressive imaging characteristics on radiographs or CT, especially in the presence of other supportive clinical features.

Long-term outcome of patients with POEMS syndrome: An update of the Mayo Clinic experience

Over the past decade, a number of changes have occurred in the diagnostic evaluation, management, and long-term follow-up of patients with POEMS syndrome at our institution. This study included 291 patients with POEMS syndrome diagnosed at the Mayo Clinic between 1974 and 2014. Patients diagnosed after 2003 had more features of the syndrome identified at diagnosis and were more likely to receive an autologous transplant (49% versus 8%, P < 0.0001) and to have achieved a hematologic complete response (CR) to treatment (41% vs 25%, P < 0.0001). With 2273 person-years of follow-up, 10-year overall survival (OS) was 62% (95% C.I., 56%, 67%). On multivariate analysis, the three factors associated with superior OS were younger age (RR 0.98 [0.96-1.00]), albumin greater-than 3.2 g/dL (RR 0.5 [0.32-0.89]) and attainment of complete hematologic response (RR 0.4 [0.2, 0.9]). This study confirms the very good long-term outcomes of patients with POEMS syndrome and identifies two new prognostic risk factors: albumin at diagnosis and attainment of complete hematologic response. Am. J. Hematol. 91:585-589, 2016. © 2016 Wiley Periodicals, Inc.

POEMS syndrome: complex factors contributing to a delayed diagnosis

POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein and skin changes) syndrome is a rare paraneoplastic syndrome due to an underlying plasma cell disorder. The chronically evolving nature of this syndrome and diverse clinical manifestations make it a challenging diagnosis, especially in the early stages of the disease. We present a case that illustrates well how these confounding factors can delay recognition of the disorder. We describe the presentation of some of the classical symptoms, and discuss how investigations can be optimised in order to fit together the clinical picture. Recent advances in the understanding of nerve conduction studies and electromyography in POEMS may help improve the early identification of this disease. This is of great importance, as early recognition and the initiation of appropriate treatment can reduce morbidity and mortality in POEMS.

POEMS syndrome: update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

POEMS syndrome is a paraneoplastic syndrome due to an underlying plasma cell neoplasm. The major criteria for the syndrome are polyradiculoneuropathy, clonal plasma cell disorder (PCD), sclerotic bone lesions, elevated vascular endothelial growth factor, and the presence of Castleman disease. Minor features include organomegaly, endocrinopathy, characteristic skin changes, papilledema, extravascular volume overload, and thrombocytosis. Diagnoses are often delayed because the syndrome is rare and can be mistaken for other neurologic disorders, most commonly chronic inflammatory demyelinating polyradiculoneuropathy. POEMS syndrome should be distinguished from the Castleman disease variant of POEMS syndrome, which has no clonal PCD and typically little to no peripheral neuropathy but has several of the minor diagnostic criteria for POEMS syndrome.

DIAGNOSIS

The diagnosis of POEMS syndrome is made with three of the major criteria, two of which must include polyradiculoneuropathy and clonal plasma cell disorder, and at least one of the minor criteria.

RISK STRATIFICATION

Because the pathogenesis of the syndrome is not well understood, risk stratification is limited to clinical phenotype rather than specific molecular markers. The number of clinical criteria is not prognostic, but the extent of the plasma cell disorder is. Those patients with an iliac crest bone marrow biopsy that does not reveal a plasma cell clone are candidates for local radiation therapy; those with a more extensive or disseminated clone will be candidates for systemic therapy.

RISK-ADAPTED THERAPY

For those patients with a dominant sclerotic plasmacytoma, first line therapy is irradiation. Patients with diffuse sclerotic lesions or disseminated bone marrow involvement and for those who have progression of their disease 3-6 months after completing radiation therapy should receive systemic therapy. Corticosteroids are temporizing, but alkylators are the mainstay of treatment, either in the form of low dose conventional therapy or high dose with stem cell transplantation. Lenalidomide shows promise with manageable toxicity. Thalidomide and bortezomib also have activity, but their benefit needs to be weighed against their risk of exacerbating the peripheral neuropathy. The benefit of anti-VEGF antibodies is conflicting. Prompt recognition and institution of both supportive care measures and therapy directed against the plasma cell result in the best outcomes.