Computed tomography assessment of bone lesions in patients with POEMS syndrome

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.

Recent Advances in the Treatment and Supportive Care of POEMS Syndrome

POEMS is a rare clonal plasma cell disorder characterized by multi-systemic features that include demyelinating peripheral neuropathy, organomegaly, endocrinopathy, presence of monoclonal proteins (M-protein), and skin changes. Even though the pathophysiology is poorly understood, recent studies suggest that both clonal and polyclonal plasmacytosis leading to the production of pro-inflammatory cytokines and angiogenic mediators play the central role. These mediators including vascular endothelial growth factor (VEGF) are the driving forces of the syndrome. The diagnosis of POEMS is not always straight forward and often the diagnosis is delayed. It is based on fulfilling mandatory criteria of polyradiculoneuropathy and monoclonal protein and the presence of one major criterion (Castleman disease, sclerotic bone lesions, or elevated VEGF), and at least one minor criterion. Due to the presence of neuropathy, it can be confused with chronic inflammatory demyelinating polyradiculopathy (CIDP), and if thrombocytosis and splenomegaly are present, it can be confused with myeloproliferative neoplasms. Due to the rarity of the syndrome, clear guidelines for treatment are still lacking. Immediate treatment targeting the underlying plasma cell proliferation results in a dramatic response in most patients. The key is early diagnosis and immediate anti-plasma cell directed therapy for the best clinical outcomes. For patients with disseminated disease as defined by bone marrow involvement or more than three osteosclerotic bone lesions, high-dose chemotherapy with autologous hematopoietic stem cell transplant (ASCT) yields durable responses and is the preferred treatment in eligible patients. For patients with localized bony disease, radiotherapy has proven to be very effective. Lenalidomide and dexamethasone is a proven therapy in patients ineligible for ASCT. In this review article, we tackle the diagnostic approach and discuss the latest treatment modalities of this rare debilitating disease.

Historical and pathological overview of Castleman disease

Castleman disease consists of several lymphoproliferative subtypes that share some histological features in the lymph nodes. On the other hand, numerous clinical findings and etiologies make the disease challenging to understand. The origin of the disease is the hyaline vascular-type unicentric Castleman disease (UCD), first reported by Benjamin Castleman et al. in 1954. Although UCD is characterized by localized lesions and lack of symptoms, multicentric Castleman disease (MCD) with multiple lesions and systemic symptoms was reported by Frizzera in 1983. MCD is further divided according to KSHV/HHV8 infection status. In KSHV/HHV8-related MCD, viral infection signals lead to excessive cytokine production, and cause clinical and pathologic abnormalities. Some cases of plasma cell-type KSHV/HHV8-negative MCD can be found in association with POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, M-proteins, and skin changes), which is a paraneoplastic syndrome. The others are idiopathic MCD, which are currently considered a heterogeneous group of diseases with overlapping pathological and clinical features. In this article, we summarize the historical evolution of Castleman disease to help understand the disease concept. We also review the latest ideas and definitions of the subtypes within the MCD spectrum and summarize the histopathological findings.

Chronic Inflammatory Demyelinating Polyradiculoneuropathy: Five New Things

Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP), while rare and heterogeneous, is one of the most common immune mediated neuropathies. CIDP, however, especially CIDP variants, can be difficult to diagnose. (1) There is no gold standard testing for CIDP, and, while a few specific disease-associated antibodies have been described, these are absent in the majority of patients. Furthermore, many experts consider the presence of these antibodies to be indicative of a separate disease. (2) Ultimately, CIDP remains a diagnosis of exclusion. Mimics are ruled out either by history or additional ancillary testing. Following experts’ guidelines on the diagnosis of CIDP increases significantly the accuracy of diagnosis. On a different note, while most patients with CIDP respond well to treatment, some may not tolerate therapy, and other may be refractory to first line treatments. In this review, we discuss 5 new things related to CIDP: 1) the updated European Academy of Neurology/Peripheral Nerve Society (EAN/PNS) CIDP guidelines, 2) the expansion of the Chronic Immune Sensory Polyradiculopathy (CISP) spectrum, 3) updates in therapy for CIDP, 4) antibodies testing, serum neurofilament light chain and their role, and 5) disorders that can mimic CIDP.

Multiple myeloma: a review of atypical imaging features and other distinct plasma cell disorders that demonstrate similar imaging features

Multiple osteolytic lesions are a well-recognized and typical imaging feature of multiple myeloma as well as several other plasma cell disorders. Given the high volume of imaging studies obtained of multiple myeloma patients, radiologists will likely encounter a subset of multiple myeloma patients with less common or "atypical" findings during their practice. These atypical findings include osteosclerotic lesions, extramedullary lesions, and amyloid deposition. Similar imaging findings that are considered atypical for multiple myeloma can also be detected in other plasma cell disorders that are distinct from multiple myeloma. For instance, POEMS syndrome is a distinct plasma cell disorder from multiple myeloma, but also can present with osteosclerotic lesions. This article reviews the atypical findings associated with multiple myeloma and also reviews other plasma cell disorders that can have a similar spectrum of imaging findings. Special attention is paid to the musculoskeletal imaging findings.

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.

CIDP mimics: a case series

Background

To report our experience with a group of patients referred for refractory CIDP who fulfilled “definite” electrodiagnostic EFNS criteria for CIDP but were found to have an alternate diagnosis.

Methods

Patients who were seen between 2017 and 2019 for refractory CIDP that fulfilled “definite” electrodiagnostic ENFS criteria for CIDP, but had an alternate diagnosis, were included. Patients who correctly had CIDP, anti MAG neuropathy, or MMN with conduction block, were excluded from the study. Demographics, clinical and electrophysiological characteristics, pertinent workup, final alternate diagnoses, and outcomes were collected.

Results

Seven patients were included: POEMS (n = 5), CANOMAD (n = 1), and neurolymphomatosis (n = 1). Most patients reported neuropathic pain and leg swelling (n = 6) or significant weight loss (n = 4). All patients had a monoclonal protein, and most patients who were tested had an elevated VEGF and CSF cyto-albuminologic dissociation. Electrophysiology showed pronounced intermediate more than distal demyelination, and axonal loss in the lower extremities. Response to steroids or IVIG varied, but some patients did respond to these treatments, especially early in the disease.

Conclusion

Pain, systemic symptoms, suggestive electrophysiological findings, and/or a serum monoclonal protein should raise suspicion for CIDP mimics. Initial response to steroids or IVIG, over reliance on CSF, and electrophysiology findings can all be misleading.

Improvement in the Symptoms and VEGF Levels after Resection of an Extrame Dullary Spinal Tumor and Additional Chemotherapy in a Patient with Multiple Myeloma Complicated with POEMS Syndrome

We herein report a case of multiple myeloma and polyneuropathy, organomegaly, endocrinopathy, myeloma protein, and skin changes (POEMS) syndrome. The patient experienced exacerbated gait disturbance due to weakness and numbness in the lower limbs. Thoracic magnetic resonance imaging revealed an extramedullary tumor with spinal compression that required surgical resection. Plasmacytoma was diagnosed based on a biopsy. Radiation, betamethasone, and chemotherapy were therefore administered. Surgical removal of extramedullary tumors improved his symptoms, motor conduction velocity, and amplitude of the muscle action potential in the peroneal and tibial nerves, as shown by the nerve conduction study. Surgery also decreased the serum vascular endothelial growth factor levels. The patient required additional chemotherapy due to multiple myeloma and showed better outcomes nine months after discharge. The benefits of some treatments remain controversial due to the small number of patients. However, our findings reveal that an early diagnosis and comprehensive treatment may result in better outcomes in such patients.

Differential diagnostic value of 18F-FDG PET/CT in osteolytic lesions

Background

Both bone metastases and multiple myeloma (MM) are malignant diseases that can appear osteolytic on imaging and are difficult to differentiate. While positron emission tomography/computed tomography (PET/CT) has been demonstrated useful for the diagnosis of various bone lesions, correlations between PET/CT and histopathology and these diseases are unclear. This retrospective study investigated the optimal cutoff standardized uptake value (SUV) to differentiate MM and bone metastasis.

Methods

Patients with newly diagnosed osteolytic lesions (n = 344) and suspected malignancy underwent both fluorodeoxyglucose (FDG) PET/CT and biopsy/surgery. FDG uptake and morphologic changes (e.g., soft tissue mass formation) were compared with pathological results.

Results

A total of 8896 osteolytic lesions were evaluated. The SUVmax of MM osteolytic lesions (1.6 ± 0.7) was significantly lower than that of bone metastases (5.5 ± 2.7; p = 0.000). The best cutoff SUVmax for differentiating MM and bone metastasis was 2.65 (sensitivity 86.1%, specificity 94.7%; p = 0.000). The SUVmax of bone lesions of soft tissue mass was higher than that for pure osteolytic lesions (p = 0.000). A greater percentage of patients with bone metastasis had a soft tissue mass (7%) than did patients with MM (2%). The mean SUVmax of bone metastases was 5.5 ± 2.7 (0.4-30.4); that of primary tumors was 7.5 ± 4.2 (1.0-28.5). The SUVmax of bone metastases significantly correlated with the SUVmax of primary tumors (r = 0.532; p = 0.000).

Conclusions

FDG PET/CT is a valuable tool to differentiate osteolytic lesions. The best cutoff value of SUVmax for differentiating MM from bone metastasis is 2.65. The significant correlation between the SUVmax of bone metastasis and that of primary tumors is helpful for detecting primary tumors.

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.

Characteristics of 1946 Cases of POEMS Syndrome in Chinese Subjects: A Literature-Based Study

POEMS syndrome is a rare paraneoplastic disorder characterized secondary to a rare plasma cell dyscrasia. Here, we aimed to analyze the clinical characteristics of large sample cases of POEMS in Chinese subjects through making a review of the Chinese literature. Four databases were electronically searched from inception until October 2016. Case reports and case series were identified. Six hundred studies with 1946 participants were identified. The first case was reported in 1986, and the number of reported cases peaked in 2009 and 2010. The top seven provinces on the number of reported cases were in the south-east area of China. The top three departments on the number of published papers and reported cases were ordinally department of Neurology, Hematology, and Endocrinology. The ratio of male to female was about 2.23. The range of age onset was from 10 to 81 years with the mean age of 46.39 (SD, 12.10 years). The initial symptoms of POEMS with peripheral neuropathy, edema and effusions, endocrinopathy, skin changes, and organomegaly accounted for 60.44, 15.72, 9.87, 8.05, and 2.13%, respectively, and subsequently acquired above symptoms as the prevalence was 99.49, 81.91, 75.56, 77.08, and 83.09%, respectively. The present study would help to understand the clinical presentations of POEMS syndrome in the Chinese population.

Neurologic Complications of Lymphoma, Leukemia, and Paraproteinemias

PURPOSE OF REVIEW

This article reviews the spectrum of neurologic complications associated with lymphoma, leukemia, and paraproteinemic disorders. While leptomeningeal metastasis is the most common complication of lymphoma and leukemia and peripheral neuropathy is the most common complication of paraproteinemic disorders, clinicians need to be familiar with the diverse neurologic complications of these disorders.

RECENT FINDINGS

Lymphomatous nervous system involvement can be difficult to diagnose, especially when it is the presenting symptom. CSF cytology and flow cytometry, as well as the imaging pattern, assist in diagnosis. Neurologic complications are less common in Hodgkin lymphoma; however, some unique paraneoplastic syndromes are associated with Hodgkin lymphoma, including primary central nervous system angiitis, limbic encephalitis, and cerebellar degeneration. Recent reports suggest that anti-metabotropic glutamate receptor 5 (mGluR5) antibodies are associated with limbic encephalitis and that anti-Tr antibodies are associated with cerebellar degeneration in Hodgkin lymphoma. Polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, and skin changes (POEMS) syndrome is often misdiagnosed as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). A lambda protein, thrombocytosis, and elevated vascular endothelial growth factor (VEGF) can all be helpful clues in diagnosis. Early recognition is important, as the neuropathy responds to radiation therapy or chemotherapy.

SUMMARY

Neurologic involvement can occur throughout the disease course in lymphoma and leukemia, including at presentation, with systemic progression, and at relapse. In paraproteinemias, the peripheral neuropathy phenotype, monoclonal protein type, and associated autonomic and systemic features aid in identification of an underlying plasma cell disorder.

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: 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.

Polyneuropathy as Novel Initial Manifestation in a Case of "Nonsecretory" POEMS Syndrome with Sjögren's Syndrome

POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes) is a paraneoplastic syndrome driven by plasma cell dyscrasias. We report a patient with novel initial manifestation of polyneuropathy, which was considered due to Sjögren's syndrome but with poor response to methylprednisolone (120 mg/d) and intravenous immunoglobulin (IVIg). Further investigation by imaging tests and following biopsy eventually confirmed the diagnosis of POEMS syndrome secondary to solitary plasmocytoma. To our knowledge, this is the first reported case of POEMS syndrome with Sjögren's syndrome occurring in the absence of a peripheral monoclonal gammopathy, highlighting the diagnostic challenges posed by this disease and reviewing the diagnostic role of (18) F-FDG PET/CT in POEMS syndrome.

Bone lesions in Chinese POEMS syndrome patients: imaging characteristics and clinical implications

Objective. Bone lesion is crucial for diagnosing and management of polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin change (POEMS) syndrome, a rare plasma cell disorder. This study is to compare the effectiveness of X-ray skeletal survey (SS) and computed tomography (CT) for detecting bone lesions in Chinese POEMS syndrome patients, and to investigate the relationship between bone lesion features and serum markers. Methods. SS and chest/abdomen/pelvic CT images of 38 Chinese patients (26 males, 12 females, aged 21-70 years) with POEMS syndrome recruited at our medical center between January 2013 and January 2015 were retrospectively analyzed. Bone lesions identified by CT were further categorized according to the size (<5 mm, 5-10 mm, >10 mm) and appearance (osteosclerotic, lytic, mixed). The percentage of plasma cells in bone marrow smears, type of immunoglobulin, platelet (Plt), and levels of serum bone metabolic markers and inflammatory factors including alkaline phosphatase (ALP), calcium, phosphate, parathyroid hormone (PTH), beta-isomerized C-telopeptide (β-CTx), vascular endothelial growth factor (VEGF), and interleukin (IL)-6 levels were also recorded. Results. Of the 38 POEMS syndrome patients, the immunoglobulin heavy chain isotypes were IgA in 25 patients (65.8%; 25/38) and IgG in 13 patients (34.2%; 13/38), and the light chain isotypes were λ in 35 patients (92.1%; 35/38) and κ in 3 patients (7.9%; 3/38). There were 23 patients with thrombocytosis. More patients with bone lesions were detected by CT than by SS (97.4% vs. 86.8%). The most commonly affected location was the pelvis (89.5%), followed by the spine, clavicle/scapula/sternum/ribs, skull, and long bones. Of the 38 POEMS syndrome patients, 35 (94.6%) had osteosclerotic and 32 (86.5%) had mixed lesions. Osteosclerotic lesions were typically scattered, variable in size, and plaque-like, whereas mixed lesions were pouch-shaped or soup bubble-like with a clear sclerotic margin and were generally larger. Although the majority of bone lesions were small in size, 23 (62.2%) had at least one lesion >10 mm. There was no correlation between serum marker levels and bone lesion patterns after Bonferroni correction (all P > 0.001). Conclusions. CT is more sensitive and accurate than SS in detecting bone lesions in POEMS syndrome.

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.