Paraneoplastic encephalitis associated with thymoma: a case report

Thymoma-associated autoimmune encephalitis: Analysis of factors determining prognosis

INTRODUCTION

Autoimmune encephalitis (AE) is a heterogeneous group of inflammatory central nervous system disorders caused by a misdirected immune response against self-antigens expressed in the central nervous system. The thymus is a central organ in the immune system and thymic tumors are thought to be possible initiators of many neurological disorders. Recently, there is growing evidence that thymomas are associated with autoimmune encephalitis.

AIMS

Our study initially explored the characteristics of patients with autoimmune encephalitis combined with thymoma.

METHODS

We used patient data from January 1, 2011 to October 1, 2021 from the PubMed, Web of Science, Ovid, and CNKI platforms to analyze overall demographics, frequency of symptoms and associations, and treatment prognosis outcomes.

RESULTS

A total of 68 patients were included. There were 39 female cases (57.4%). The mean age was 50 years (IQR 40-66 years). All had acute and subacute onset. The clinical manifestations were mostly cognitive changes (70.6%), mental disorders (57.4%), and epilepsy (50.0%). The most common neuronal antibody was alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA). Magnetic resonance imaging (MRI) abnormalities were present in 81.0% of patients, mostly in the hippocampus, temporal lobe, and some in cortical and subcortical areas. Abnormalities in the electroencephalogram (EEG) in 69.8% of patients. Treatment involved immunotherapy and thymoma treatment, with 79.7% of patients improving after treatment. While 20.3% of patients had a poor prognosis. Further, 14.8% of patients relapsed. Mental disorders, autonomic dysfunction, sleep disturbances, anti-Ma2, and thymoma untreated were more frequent in patients with poor prognosis.

CONCLUSION

Thymoma-associated autoimmune encephalitis is a unique disease entity. Long-term follow-up of chest CT findings is recommended for patients with autoimmune encephalitis.

A systematic review of paraneoplastic syndromes associated with thymoma: Treatment modalities, recurrence, and outcomes in resected cases

OBJECTIVE

Paraneoplastic syndromes associated with thymomas remain incompletely understood. The objective was to examine the association between surgically resected thymomas and paraneoplastic syndromes over the past half century.

METHODS

A primary PubMed/MEDLINE search was used to identify published articles describing paraneoplastic syndromes associated with thymomas from 1960 to 2019. A secondary search identified additional articles referenced in the articles found in the primary search. Kaplan-Meier and log-rank test were used for time-to-event data analyses.

RESULTS

From 407 articles describing 507 patients, 123 different paraneoplastic syndromes were associated with thymoma. The 5 most common paraneoplastic syndromes were myasthenia gravis, pure red cell aplasia, lichen planus, Good syndrome, and limbic encephalitis. Complete or partial resolution of paraneoplastic syndrome symptoms after surgery was noted in 76% of patients, of whom 21% had a relapse or new paraneoplastic syndrome onset after surgery. The most common adjunctive therapy associated with resolution of paraneoplastic syndrome was corticosteroids (30%). For all patients after surgery, thymoma recurrence was observed in 17% of cases, whereas recurrence of paraneoplastic syndrome was observed in 34% of cases, and both were observed in approximately 11% of cases. The 5- and 10-year overall survivals were 78% and 66%, respectively. Improved overall survival was associated with patients who had total resolution from paraneoplastic syndrome.

CONCLUSIONS

A comprehensive assessment of publications over the past half century suggests that a multimodal treatment approach that includes surgical resection of thymomas is able to achieve paraneoplastic syndrome resolution in a majority of patients. Onset of new paraneoplastic syndromes after surgery is associated with the recurrence of the first paraneoplastic syndrome, and resolution of paraneoplastic syndrome is associated with improved overall survival.

Thymoma-associated panencephalitis: a newly emerging paraneoplastic neurologic syndrome

Recently, a few case reports of thymoma-associated panencephalitis (TAPE) have brought to light a disease entity that has not been fully characterized. Literature review of TAPE reveals an array of associated neuronal antibodies, with varied responses to thymomectomy with or without immunotherapy. This report describes a case of TAPE and proposes that the GABA_A receptor antibody is a potential target antigen driving the immune process in this disease entity. Treatment-wise, early thymomectomy consistently improves the overall course of disease. Further study of such cases will be critical in clarifying the mechanisms of disease, improving early diagnosis, and developing targeted approaches to treatment.

A Case Series of Patients With Autoimmune Myasthenia Gravis in Association With Invasive Thymoma

OBJECTIVES

In some patients, autoimmune myasthenia gravis (MG) is associated with thymic hyperplasia or thymoma, and in some patients the thymoma is invasive. Little is known about the clinical course of subjects who present with MG and are found to have invasive thymoma.

METHODS

We reviewed the patients at our clinic with MG and invasive thymoma, and have described their clinical features.

RESULTS

Six MG patients were diagnosed with invasive thymoma. The subjects had extensive multimodal therapy. Two subjects died from uncontrolled neuromuscular respiratory failure despite aggressive immunosuppression, 2 subjects had other autoimmune disorders (Morvan syndrome and polymyositis), and 2 subjects are controlled on immunosuppression.

CONCLUSIONS

Patients with invasive thymoma and MG can have a poor outcome, with difficulty in controlling myasthenic symptoms and can have other clinically important autoimmune diseases.

Paraneoplastic extralimbic encephalitis associated with thymoma: a case report

Here we a report a rare case of extralimbic encephalitis associated with thymoma. A 66-year-old woman was admitted to our hospital with cramping in her right leg and inability to walk. Magnetic resonance imaging of the brain showed multifocal high intensity signals on T2 flare images in the cerebral cortex, and chest computed tomography showed a 5-cm anterior mediastinal mass, which was considered to be a thymoma. We speculated that she had paraneoplastic encephalitis associated with thymoma. She underwent a thymectomy and was diagnosed with type B1 thymoma. On postoperative day 6, her neurological symptoms began to improve. On postoperative day 31, she was discharged without complications. Limbic encephalitis is a paraneoplastic neurological syndromeassociated with thymoma, but extralimbic encephalitis has been described in the literature very rarely. We report the case of extralimbic encephalitis associated with thymoma along with a literature review.