Paraneoplastic syndromes: Definitions, classification, pathophysiology and principles of treatment

Endocrine paraneoplastic syndromes in lung cancer: A call for clinical vigilance (Review)

Endocrine paraneoplastic syndromes (PNS) are uncommon but clinically impactful manifestations associated with malignancies, particularly lung cancer, most notably small-cell lung cancer. These syndromes arise from ectopic hormone production by malignant cells, causing systemic effects that are independent of direct tumor invasion or metastasis. Their presentation often precedes or signals recurrence of the primary cancer, underscoring the importance of early recognition and targeted intervention. Common endocrine PNS in lung cancer include syndrome of inappropriate antidiuretic hormone secretion, hypercalcemia, Cushing syndrome, carcinoid syndrome, and other hormonal imbalances such as non-islet cell tumor hypoglycemia, gynecomastia and acromegaly. The pathophysiology of these conditions involves ectopic secretion of bioactive substances such as hormones and cytokines, leading to diverse clinical manifestations. Accurate diagnosis necessitates a combination of biochemical assessments, imaging modalities, and histopathological evaluations to differentiate paraneoplastic processes from primary endocrine disorders. Management strategies emphasize treating the underlying malignancy, often through chemotherapy, radiotherapy, or surgical intervention, alongside symptomatic therapies tailored to the specific endocrine abnormality. Multidisciplinary care is critical for optimizing outcomes and enhancing patients' quality of life. The current review highlights the need for heightened clinical vigilance and a systematic approach to diagnosing and managing endocrine PNS in lung cancer. By fostering early detection and comprehensive management, clinicians can significantly improve prognostic outcomes for affected individuals.

Paraneoplastic production of human chorionic gonadotropin by paratesticular dedifferentiated liposarcoma with rhabdomyosarcomatous differentiation

A man in his 70s presented with a left inguinoscrotal mass. Testicular tumour markers showed markedly elevated human chorionic gonadotropin (hCG). The 24.5 cm mass was resected, and histology confirmed a rare diagnosis of paratesticular dedifferentiated liposarcoma (DDLPS) with rhabdomyosarcomatous differentiation. The patient expired with distant metastasis 11 months after presenting to his general practitioner.HCG-producing soft tissue sarcomas (STS) are commonly reported as high-grade, poorly differentiated and with a poor prognosis. The role of hCG in tumour angiogenesis may influence these features.Paratesticular STS treatment guidelines have been influenced by the management of retroperitoneal STS, which are relatively more common. Studies of genitourinary STS demonstrate that positive surgical margins pose the greatest risk to local recurrence and metastasis-free survival.This case demonstrates the rapid growth of DDLPS-producing hCG, the propensity to metastasise, and poor prognosis, requiring further research into the benefit of adjuvant radiotherapy for DDLPS.

The Diverse Evolutionary Histories of Domesticated Metaviral Capsid Genes in Mammals

Selfish genetic elements comprise significant fractions of mammalian genomes. In rare instances, host genomes domesticate segments of these elements for function. Using a complete human genome assembly and 25 additional vertebrate genomes, we re-analyzed the evolutionary trajectories and functional potential of capsid (CA) genes domesticated from Metaviridae, a lineage of retrovirus-like retrotransposons. Our study expands on previous analyses to unearth several new insights about the evolutionary histories of these ancient genes. We find that at least five independent domestication events occurred from diverse Metaviridae, giving rise to three universally retained single-copy genes evolving under purifying selection and two gene families unique to placental mammals, with multiple members showing evidence of rapid evolution. In the SIRH/RTL family, we find diverse amino-terminal domains, widespread loss of protein-coding capacity in RTL10 despite its retention in several mammalian lineages, and differential utilization of an ancient programmed ribosomal frameshift in RTL3 between the domesticated CA and protease domains. Our analyses also reveal that most members of the PNMA family in mammalian genomes encode a conserved putative amino-terminal RNA-binding domain (RBD) both adjoining and independent from domesticated CA domains. Our analyses lead to a significant correction of previous annotations of the essential CCDC8 gene. We show that this putative RBD is also present in several extant Metaviridae, revealing a novel protein domain configuration in retrotransposons. Collectively, our study reveals the divergent outcomes of multiple domestication events from diverse Metaviridae in the common ancestor of placental mammals.

Paraneoplastic Syndromes in Neuroendocrine Prostate Cancer: A Systematic Review

Neuroendocrine prostate cancer (NEPC) is a rare subtype of prostate cancer (PCa) that usually results in poor clinical outcomes and may be accompanied by paraneoplastic syndromes (PNS). NEPC is becoming more frequent. It can initially manifest as PNS, complicating diagnosis. Therefore, we reviewed the literature on the different PNS associated with NEPC. We systematically reviewed English-language articles from January 2017 to September 2023, identifying 17 studies meeting PRISMA guidelines for NEPC and associated PNS. A total of 17 articles were included in the review. Among these, Cushing's Syndrome (CS) due to ectopic Adrenocorticotropic hormone (ACTH) secretion was the most commonly reported PNS. Other PNS included syndrome of inappropriate Anti-Diuretic Hormone secretion (SIADH), Anti-Hu-mediated chronic intestinal pseudo-obstruction (CIPO), limbic encephalitis, Evans Syndrome, hypercalcemia, dermatomyositis, and polycythemia. Many patients had a history of prostate adenocarcinoma treated with androgen deprivation therapy (ADT) before neuroendocrine features developed. The mean age was 65.5 years, with a maximum survival of 9 months post-diagnosis. NEPC is becoming an increasingly more common subtype of PCa that can result in various PNS. This makes the diagnosis and treatment of NEPC challenging. Further research is crucial to understanding these syndromes and developing standardized, targeted treatments to improve patient survival.

Overview of Paraneoplastic Autoantibody-Mediated Cognitive Impairment and Behavioral Changes: A Narrative Review

Cognitive dysfunction and behavioral change can be some of the manifestations of cancer, occurring as a part of paraneoplastic neurological syndrome, most commonly in small cell lung cancer. Paraneoplastic limbic encephalitis is the leading cause of cognitive disturbance and abnormal behavior in paraneoplastic syndromes, which is usually autoantibody-mediated. Autoantibodies are the main contributors to the development of cognitive dysfunction and behavioral change in cancer patients, with studies suggesting a higher liability for antibody-positive cancer patients to be affected. Anti-NMDAR and anti-AMPAR are antibodies targeted against surface antigens, manifesting predominantly as memory disturbance, abnormal behavior, psychiatric symptoms, and seizures. Other surface antigen-targeted antibodies include anti-GABA, anti-CASPR2, and anti-LGI1, which were shown to have cognitive function impairment and abnormal behavior as some of the main presentations, predominantly affecting memory. Cognitive deterioration and changes in behavior were also relatively common with some of the intracellular antigen-targeted antibodies, including anti-Hu, anti-SOX1, anti-PCA2, and anti-Zic2. Affected behavior and cognition, however, were reported less commonly in other paraneoplastic antibodies against intracellular antigens (anti-Yo, anti-GAD, anti-Ma2, anti-Ri, anti-CV2, and anti-KLHL11). Our article will provide a comprehensive review of the clinical manifestations of cognitive impairment and behavioral changes among cancer patients who develop paraneoplastic syndrome. Additionally, this review will discuss the role of specific paraneoplastic autoantibodies and the clinical spectrum linked to each separately.

Immunopathology of herpes simplex virus-associated neuroinflammation: Unveiling the mysteries

The immunopathology of herpes simplex virus (HSV)-associated neuroinflammation is a captivating and intricate field of study within the scientific community. HSV, renowned for its latent infection capability, gives rise to a spectrum of neurological expressions, ranging from mild symptoms to severe encephalitis. The enigmatic interplay between the virus and the host's immune responses profoundly shapes the outcome of these infections. This review delves into the multifaceted immune reactions triggered by HSV within neural tissues, intricately encompassing the interplay between innate and adaptive immunity. Furthermore, this analysis delves into the delicate equilibrium between immune defence and the potential for immunopathology-induced neural damage. It meticulously dissects the roles of diverse immune cells, cytokines, and chemokines, unravelling the intricacies of neuroinflammation modulation and its subsequent effects. By exploring HSV's immune manipulation and exploitation mechanisms, this review endeavours to unveil the enigmas surrounding the immunopathology of HSV-associated neuroinflammation. This comprehensive understanding enhances our grasp of viral pathogenesis and holds promise for pioneering therapeutic strategies designed to mitigate the neurological ramifications of HSV infections.

The diverse evolutionary histories of domesticated metaviral capsid genes in mammals

Selfish genetic elements and their remnants comprise at least half of the human genome. Active transposons duplicate by inserting copies at new sites in a host genome. Following insertion, transposons can acquire mutations that render them inactive; the accrual of additional mutations can render them unrecognizable over time. However, in rare instances, segments of transposons become useful for the host, in a process called gene domestication. Using the first complete human genome assembly and 25 additional vertebrate genomes, we analyzed the evolutionary trajectories and functional potential of genes domesticated from the capsid genes of Metaviridae, a retroviral-like retrotransposon family. Our analysis reveals four families of domesticated capsid genes in placental mammals with varied evolutionary outcomes, ranging from universal retention to lineage-specific duplications or losses and from purifying selection to lineage-specific rapid evolution. The four families of domesticated capsid genes have divergent amino-terminal domains, inherited from four distinct ancestral metaviruses. Structural predictions reveal that many domesticated genes encode a previously unrecognized RNA-binding domain retained in multiple paralogs in mammalian genomes both adjacent to and independent from the capsid domain. Collectively, our study reveals diverse outcomes of domestication of diverse metaviruses, which led to structurally and evolutionarily diverse genes that encode important, but still largely-unknown functions in placental mammals. (207).

The role of [18F]FDG PET/CT in paraneoplastic autoimmune disorders: an umbrella review

Paraneoplastic autoimmune disorders (PAD) are a group of autoimmune diseases associated with neoplasms. Several evidence-based articles (systematic reviews and meta-analyses) have reported data about the role of positron emission tomography (PET) and related hybrid modalities (e.g., PET/CT) using 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) in patients with PAD. We performed an umbrella review of published systematic reviews and meta-analyses in this setting to provide an evidence-based summary and suggestions for further studies. Several databases were searched to find systematic reviews and meta-analysis on [18F]FDG PET/CT in PAD. Evidence-based data support the use of [18F]FDG PET/CT in patients with suspected PAD for investigating an underlying malignancy even if it is still unclear whether [18F]FDG PET/CT should be performed after negative/inconclusive conventional imaging or as part of the initial workup of PAD.

Chronic urticaria associated with lung adenocarcinoma — a paraneoplastic manifestation: A case report and literature review

BACKGROUND

Urticaria is one of the most common causes of emergency room visits. It is defined as an acute inflammatory dermatosis, characterized by localized degranulation of mast cells, with consequent dermal microvascular and formation of edematous and pruritic plaques called hives. Urticaria affects the skin and tissues of the superficial mucosa. Sometimes it is accompanied by angioedema, which is characterized by deeper edema of the dermis and subcutaneous cellular tissue known as the urticarial-angioedema syndrome. About 15%-25% of the general population has suffered at least one type of urticaria at some point during their lifetime and hyperpermeability estimated at 7.6%-16% and has experienced acute urticaria that is usually self-limited and spontaneously resolves without requiring medical attention.

CASE SUMMARY

We present the case of a young male patient who was referred to our department with a clinical picture of 4 mo of pruritus associated with hives of variable sizes, irregular borders, with interlesional confluence, that were non-painful, without involvement of the palms and soles of the feet but with a tendency to progression in a generalized manner. He had multiple emergency room visits and poor response to antihistamines and systemic corticosteroids. Imaging studies demonstrated nodules in the lower lingula segment, at the level of the greater fissure and in the anterior contour of the left anterior basal segment associated with parahiliar adenopathies in the absence of findings suggestive of infectious or autoimmune etiology. Segmental lobectomy was performed by thoracoscopy with resection of a lung nodule in the lingula and biopsy of the para-aortic mediastinal ganglion. The histopathological report showed the presence of poorly differentiated invasive adenocarcinoma with a solid morphological and acinar pattern with immunohistochemical description of lung tissue that expresses strong positive and diffuse reaction for thyroid transcription factor 1 (TTF-1) with negativity to P40 for a histopathological diagnosis of malignant epithelial neoplasia with expression of infiltrating adenocarcinoma. Spontaneous chronic urticaria is considered possibly secondary to lung adenocarcinoma.

CONCLUSION

Chronic spontaneous urticaria is considered a paraneoplastic dermatosis with a controversial association in the literature. In the presented case, a young patient presented with chronic refractory urticaria and after an exhaustive clinical work-up was found to have a diagnosis of poorly differentiated lung adenocarcinoma with high expression of TTF-1. According to the Curth criteria, the urticaria presented by the patient is related to the oncological diagnosis. In addition, the high expression of TTF-1 documented in this case could be acting as an autoantigen that would cause chronic spontaneous urticaria. Further research evaluating a causal relationship between the TFF-1 protein and urticaria in lung cancer is needed.

Systemic Disease Associations with Disorders of Gut-Brain Interaction and Gastrointestinal Transit: A Review

Functional gastrointestinal disorders (FGID) are now classified within the Rome IV framework as disorders of gut-brain interaction (DGBI). Disorders of gastrointestinal transit (as defined by abnormalities on contemporary gastrointestinal motility testing) frequently are associated with symptoms that are also characteristic of DGBIs. In this narrative review, we outline a non-inclusive set of systemic diseases or risk factors that have been classically associated with DGBIs and disorders of gastrointestinal transit; these include diabetes mellitus, paraneoplastic syndromes, surgery, Parkinson's disease, systemic sclerosis, endocrinopathies, polypharmacy, and post-infectious syndromes.

Alloimmune Myositis as Paraneoplastic Complication of an Oral Squamous Cell Carcinoma After Severe Chronic Graft vs Host Disease or a Manifestation of Chronic Graft vs Host Disease? A Case Report and Literature Discussion

A 53-year-old female patient with acute myeloid leukemia developed severe chronic graft vs host disease (cGVHD) of the oral mucosa after allogeneic hematopoietic stem cell transplantation with leukoplakia and relapsing oral squamous cell carcinoma (SCC) of the tongue. cGVHD needed long-lasting immunosuppressive therapy; SCC was treated with radiation and surgery. Acute myeloid leukemia remained in complete remission. The patient developed a myositis with pain of all muscles as well as paraparesis with elevated creatine kinase and C-reactive protein and detection of antiskeletal muscle autoantibodies 3500 days after hematopoietic stem cell transplantation. No other clinical features of chronic GVHD were apparent at this time. Symptoms disappeared after treatment with corticosteroids but relapsed while tapering. Weekly therapy with the B-cell-depleting antibody rituximab was started and administered for 6 weeks. Symptoms disappeared again but partly returned after some weeks, so therapy with azathioprine was started. During therapy with azathioprine slow tapering of corticosteroids was possible and clinical symptoms remained absent. Here we present a case report and review of the literature on alloimmune myositis as paraneoplastic complication of an oral SCC of the tongue after severe chronic GVHD or as late manifestation of chronic GVHD itself.

Autoimmune disorders and paraneoplastic syndromes in thymoma

Thymomas are counted among the rare tumour entities which are associated with autoimmune disorders (AIDs) and paraneoplastic syndromes (PNS) far more often than other malignancies. Through its complex immunological function in the context of the selection and maturation of T cells, the thymus is at the same time highly susceptible to disruptive factors caused by the development and growth of thymic tumours. These T cells, which are thought to develop to competent immune cells in the thymus, can instead adopt autoreactive behaviour due to the uncontrolled interplay of thymomas and become the trigger for AID or PNS affecting numerous organs and tissues within the human body. While myasthenia gravis is the most prevalent PNS in thymoma, numerous others have been described, be they related to neurological, cardiovascular, gastrointestinal, haematological, dermatological, endocrine or systemic disorders. This review article sheds light on the pathophysiology, epidemiology, specific clinical features and therapeutic options of the various forms as well as courses and outcomes of AID/PNS in association with thymomas. Whenever suitable and backed by the limited available evidence, the perspectives from both the thymoma and the affected organ/tissue will be highlighted. Specific issues addressed are the prognostic significance of thymectomy on myasthenia gravis and other thymoma-associated AID/PND and further the impact and safety of immunotherapies on AID and PND relating to thymomas.

Lung Cancer Cell-Derived Secretome Mediates Paraneoplastic Inflammation and Fibrosis in Kidney in Mice

Simple Summary

Paraneoplastic nephrotic syndrome is a complication arising in lung cancer patients. In the present study, we established an LLC1 cell orthotopic xenograft C57BL/6 mice model to translation paraneoplastic nephrotic syndrome (PNS). The pathological aspects of PNS were characterized in TGF-β signaling-engaged renal fibrosis, and renal inflammation with IL-6 expression in kidney. To reveal how the lung cancer cells remotely drive pathogenic progression, secretome derived from LLC1 cells and A549 cells were proteomically profiled. Additionally, the secretome profiling was subjected to diseases and biofunctions assessment by Ingenuity Pathway analysis (IPA). As matter of secretome profiling and IPA prediction, the Fibronectin, C1r, and C1s are potential of nephrotoxicity linked to paraneoplastic effects on glomerular pathogenesis in these lung cancer mice.

Abstract

Kidney failure is a possible but rare complication in lung cancer patients that may be caused by massive tumor lysis or a paraneoplastic effect. Clinical case reports have documented pathological characteristics of paraneoplastic syndrome in glomeruli, but are short of molecular details. When Lewis lung carcinoma 1 (LLC1) cells were implanted in mice lungs to establish lung cancer, renal failure was frequently observed two weeks post orthotopic xenograft. The high urinary albumin-to-creatinine ratio (ACR) was diagnosed as paraneoplastic nephrotic syndrome in those lung cancer mice. Profiling the secretome of the lung cancer cells revealed that the secretory proteins were potentially nephrotoxic. The nephrotoxicity of lung cancer-derived secretory proteins was tested by examining the pathogenic effects of 1 × 10⁶, 2 × 10⁶, and 5 × 10⁶ LLC1 cell xenografts on the pathogenic progression in kidneys. Severe albuminuria was present in the mice that received 5 × 10⁶ LLC1 cells implantation, whereas 10⁶ cell and 2 × 10⁶ cell-implanted mice have slightly increased albuminuria. Pathological examinations revealed that the glomeruli had capillary loop collapse, tumor antigen deposition in glomeruli, and renal intratubular casts. Since IL-6 and MCP-1 are pathologic markers of glomerulopathy, their distributions were examined in the kidneys of the lung cancer mice. Moderate to severe inflammation in the kidneys was correlated with increases in the number of cells implanted in the mice, which was reflected by renal IL-6 and MCP-1 levels, and urine ACR. TGF-β signaling-engaged renal fibrosis was validated in the lung cancer mice. These results indicated that lung cancer cells could provoke inflammation and activate renal fibrosis.

Deep pemphigus (pemphigus vulgaris, pemphigus vegetans and paraneoplastic pemphigus) in dogs, cats and horses: a comprehensive review

Pemphigus is the term used to describe a group of rare mucocutaneous autoimmune bullous diseases characterized by flaccid blisters and erosions of the mucous membranes and/or skin. When the autoantibodies target desmosomes in the deep layers of the epidermis, deep pemphigus variants such as pemphigus vulgaris, pemphigus vegetans and paraneoplastic pemphigus develop. In this article, we will review the signalment, clinical signs, histopathology and treatment outcome of pemphigus vulgaris, pemphigus vegetans and paraneoplastic pemphigus in dogs, cats and horses; where pertinent, we compare the animal diseases to their human homologue. Canine, feline and equine pemphigus vulgaris, pemphigus vegetans and paraneoplastic pemphigus have many features similar to the human counterpart. These chronic and often relapsing autoimmune dermatoses require aggressive immunosuppressive therapy. In animals, the partial-to-complete remission of pemphigus vulgaris and pemphigus vegetans has been achieved with high dose glucocorticoid therapy, with or without adjunct immunosuppressants; the prognosis is grave for paraneoplastic pemphigus.

Multiple intracranial lesions with lung adenocarcinoma: A rare case of MOG-IgG-associated encephalomyelitis

BACKGROUND

Myelin oligodendrocyte glycoprotein (MOG) is an important marker on the surface of oligodendrocytes and is associated with many demyelinating diseases. Recently, MOG-IgG-associated encephalomyelitis (MOG-EM) has been proposed as a disease entity with a preliminary diagnosis standard. Some patients with lung cancer have been reported to be seropositive for onconeural antibodies; however, lung cancer cases with MOG-EM have not been previously reported.

METHODS

We report the case of a patient with lung adenocarcinoma with multiple intracranial lesions found during molecular targeted therapy.

RESULTS

The patient tested positive for MOG antibody in her cerebrospinal fluid, and the therapeutic effect of steroids was excellent.

CONCLUSION

This is the first reported case of MOG-EM coincident with lung cancer in a patient with multiple intracranial lesions. When patients present with a history of malignant tumors or suspected paraneoplastic neurological syndrome, clinicians should also be alert to the presence of other autoimmune antibodies such as MOG-IgG to avoid treatment delay.

Big Insulin-like Growth Factor 2-Producing Tumor in a Hypoglycemic Dog

A 10-year-old female Papillon dog that had previously developed a mammary tumor was admitted for treatment of a hypoglycemic attack. Blood examination showed severe hypoglycemia and decreased blood insulin concentration. Computed tomography indicated multiple tumors in the cranial and caudal lobes of the right lung. These tumors were resected surgically and diagnosed as pulmonary adenocarcinomas by histopathologic examination. Hypoglycemia was temporarily improved after the resection, but a hypoglycemic event occurred 2 months after the surgery. Immunohistochemistry of the tumor demonstrated the expression of insulin-like growth factor 2 in tumor cells. Western blot analysis revealed the expression of high-molecular-weight (big)-insulin-like growth factor 2 in the tumor region. Insulin-like growth factor 2 mRNA expression was also confirmed in the tumor using reverse transcription-polymerase chain reaction. These findings indicate the diagnosis of non-islet cell tumor-induced hypoglycemia caused by big-insulin-like growth factor 2 produced by the tumor in the dog. This report provides information on differentiating tumors that cause paraneoplastic hypoglycemia.

Dermatomyositis presenting as heart failure revealed a concealed cervical malignancy: an infrequent clinical nexus

Dermatomyositis (DM) belongs to the spectrum of inflammatory myopathies which are a heterogeneous group of acquired disorders in which dysregulated immune system is thought to play a major pathologic role. Patients with DM generally present with characteristic skin manifestations with or without muscle weakness and pain. Although subclinical myocardial involvement in DM is well reported in literature, heart failure (HF) as its principal manifestation is extremely rare. Recognition of DM, a known paraneoplastic syndrome, should prompt clinicians to search for underlying malignancy. While gynaecological malignancies are common in association with DM, cervical cancer has rarely been heard of as an aetiology of paraneoplastic DM. We are reporting a case of DM in a postmenopausal woman presenting with advanced decompensated congestive HF with hidden squamous cell carcinoma of cervix.

Paraneoplastic Syndromes Associated with Laryngeal Cancer

OBJECTIVES

Paraneoplastic syndromes occur rarely in association with laryngeal cancer. When present, the syndrome may be the first sign of the malignancy. The aim of the present study was to review and report on all published cases in the international literature.

METHODS

A search of PubMed was conducted for "paraneoplastic syndromes in laryngeal cancer" without any restrictions on language or publication year. The full texts of all relevant articles were reviewed and all cases of paraneoplastic syndromes associated with any type of laryngeal cancer were extracted and analyzed.

RESULTS

We identified 59 cases of paraneoplastic syndromes related to laryngeal cancer in the literature published from 1963 until recently. There were 46 squamous cell carcinomas and 10 neuroendocrine carcinomas. Twenty-two of the paraneoplastic syndromes involved the endocrine system, 21 were dermatologic or cutaneous, 8 neurologic, 5 osteoarticular or rheumatologic, 1 ocular, 1 muscular, and 1 hematologic. Treatment strategies included surgery, radiotherapy, chemotherapy, and often multimodal therapy, depending on the histology and stage of the laryngeal cancer.

CONCLUSIONS

Because of their rarity, paraneoplastic syndromes associated with laryngeal cancer are difficult to diagnose. By presenting and systematically reviewing all published cases in the international literature, the present review may help clinicians to recognize them and to suspect the diagnosis of laryngeal cancer at an earlier stage than otherwise might be possible.

Worsening and newly diagnosed paraneoplastic syndromes following anti-PD-1 or anti-PD-L1 immunotherapies, a descriptive study

Background

Paraneoplastic syndromes (PNS) are autoimmune disorders specifically associated with cancer. There are few data on anti-PD-1 or anti-PD-L1 immunotherapy in patients with a PNS. Our objective was to describe the outcome for patients with a pre-existing or newly diagnosed PNS following the initiation of anti-PD-1 or anti-PD-L1 immunotherapy.

Methods

We included all adult patients (aged ≥18) treated with anti-PD-1 or anti-PD-L1 immunotherapy for a solid tumor, diagnosed with a PNS, and registered in French pharmacovigilance databases. Patients were allocated to cohorts 1 and 2 if the PNS had been diagnosed before vs. after the initiation of immunotherapy, respectively.

Findings

Of the 1304 adult patients screened between June 27th, 2014, and January 2nd, 2019, 32 (2.45%) had a PNS and were allocated to either cohort 1 (n = 16) or cohort 2 (n = 16). The median (range) age was 64 (45–88). The tumor types were non-small-cell lung cancer (n = 15, 47%), melanoma (n = 6, 19%), renal carcinoma (n = 3, 9%), and other malignancies (n = 8, 25%). Eleven (34%) patients presented with a neurologic PNS, nine (28%) had a rheumatologic PNS, eight (25%) had a connective tissue PNS, and four (13%) had other types of PNS. The highest severity grade for the PNS was 1–2 in 10 patients (31%) and ≥ 3 in 22 patients (69%). Four patients (13%) died as a result of the progression of a neurologic PNS (encephalitis in three cases, and Lambert-Eaton syndrome in one case). Following the initiation of immunotherapy, the PNS symptoms worsened in eight (50%) of the 16 patients in cohort 1.

Interpretation

Our results show that PNSs tend to be worsened or revealed by anti-PD-1 or anti-PD-L1 immunotherapy. Cases of paraneoplastic encephalitis are of notable concern, in view of their severity. When initiating immunotherapy, physicians should carefully monitor patients with a pre-existing PNS.

Paraneoplastic Syndrome Associated with the Retroperitoneal Dedifferentiated Liposarcoma: an Atypical Presentation and Review of the Literature

Retroperitoneal liposarcoma is usually asymptomatic until it is large enough to compress the surrounding organs. Here, we report a rare atypical case of primary retroperitoneal dedifferentiated liposarcoma who presented primarily with the misguiding and challenging paraneoplastic symptoms of high-grade fever and thrombocytosis instead of demonstrating the usual compressive symptoms. Such an extremely rare clinical presentation may mislead the diagnostic and treatment approach towards the search for medical causes, without a hint, that the tumor itself is causing these symptoms. Complete tumor excision usually leads to resolution of these paraneoplastic symptoms.