Myasthenia gravis, an autoimmune manifestation of lymphoma and lymphoproliferative disorders: case reports and review of literature

Abstract

Myasthenia gravis (MG) is an autoimmune disease mediated by antibodies to acetylcholine receptors (AChRs) or muscle specific tyrosine kinase (MuSK). While the frequent association of MG with thymoma in patients aged 40-60 years is well recognized, its occurrence in patients with lymphoma has not been well studied. We review the literature on the association of MG and lymphoid malignancies and report two new patients. MG can occur in a synchronous or non-synchronous fashion with lymphoma. The pathogenesis of MG in lymphoid malignancies is probably heterogeneous and likely relates to perturbations in the immune mechanisms that normally prevent the emergence of autoimmunity. These perturbations could be the result of the lymphoid malignancy per se, or its treatment.

A benign cancer with malicious paraneoplastic syndromes

“…With a prevalence of only 200–700 cases/million1 MG is a comparatively rare condition, but only a handful of cases have been described for MG appearing in the context of lymphoma 2. Of the 21 known cases summarised in a recent review2 19 improved under treatment and 2 deaths were cases unrelated to the myasthenia.…”

“…Of the 21 known cases summarised in a recent review2 19 improved under treatment and 2 deaths were cases unrelated to the myasthenia. Eighteen of them were positive for acetylcholine receptor antibodies and one for the MuSK antibody.…”

“…In all cases there was a close temporal association between the occurrence of the two diseases. This suggests that MG can occur as a paraneoplastic syndrome 2. Improvement of the myasthenic symptoms is described in most cases where the lymphoma is controlled 2.…”

Paraneoplastic neurological syndromes in Hodgkin and non-Hodgkin lymphomas

“…103,104 A few cases of myasthenia gravis have been described in association with HL and T-cell NHL with involvement of the mediastinum. 105 In 50% of the cases with lymphoma and LEMS or myasthenia, the neurological disorder develops around the time of the diagnosis of lymphoma. For the rest of patients, the lymphoma and neurological disorder are separated by many years, suggesting the presence of an underlying immunological disturbance caused by the tumor or immunosuppression that predisposes to the paraneoplastic immune-mediated syndrome.…”

Miastenia gravis y su asociación con trastornos linfoproliferativos: casos clínicos

“…En relación con MG se han reportado alrededor de 50 casos de neoplasia linfoide, lo que sugiere una relación mayor que la simple casualidad 7 . Con el objeto de investigar esta asociación, realizamos una revisión de los pacientes con MG (alrededor de 90) atendidos en nuestro hospital e identificamos entre el 2013-2016, cuatro pacientes que desarrollaron una neoplasia linfoproliferativa.…”