Rare case of LEMS associated with non-Hodgkin lymphoma: Report
Researchers suggest muscle weakness without cause should be tested for LEMS
The rare case of a man with Lambert-Eaton myasthenia syndrome (LEMS) that co-occurred with non-Hodgkin lymphoma, a type of immune cell cancer, was described in a recent report.
“In this case report, we present the case of a 57-year-old male diagnosed with non-Hodgkin’s lymphoma (NHL) who developed LEMS, an exceedingly rare co-occurrence,” the researchers wrote, adding that “recognition and timely management of LEMS alongside lymphoma treatment can lead to significant clinical improvement, emphasizing the need for increased awareness of such complex associations.”
The case was described in the study, “A Rare Case of Lambert-Eaton Myasthenia Syndrome Associated with Non-Hodgkin’s Lymphoma: A Case Report and Review of the Literature,” published in the journal Case Reports in Oncology.
LEMS is an autoimmune disease caused by antibodies that interfere with the communication between nerve and muscle cells by binding to proteins called voltage-gated calcium channels (VGCCs) on nerve cell endings. This reduces signals sent from nerves to instruct muscle cells to contract, ultimately resulting in muscle weakness and other symptoms.
LEMS can occur without other diseases, but it often develops in people who have cancer, particularly small-cell lung cancer.
“Patients with neoplastic diseases [tumor growth disorders] other than [small-cell lung cancer] have been reported in very few LEMS cases,” the researchers wrote.
Here, researchers in the U.S. and Qatar described the case of a 57-year-old man who sought medical attention due to a series of symptoms that included vomiting, abdominal distention, and weight loss.
Imaging tests revealed the man had enlarged lymph nodes, and subsequent tests found signs of abnormal immune cell growth, confirming the diagnosis of non-Hodgkin lymphoma, more specifically a subtype called peripheral T-cell lymphoma, or PTCL.
“PTCL is a rare and aggressive subtype of lymphoma,” the researchers wrote, adding that patients with this type of cancer, which mainly affects men older than 60, “have some of the poorest long-term survival rates of blood malignancies.”
The man was initially given an immune-suppressing medication called dexamethasone, but he developed an infection that required several weeks of intensive treatment to control. Once the infection was managed, he was transferred to a cancer center and started chemotherapy.
Muscle weakness led to a conclusion of LEMS
Over the course of his treatment, the man started to experience unexplained muscle weakness, which prompted a neurological evaluation. Results were indicative of a disorder where signals sent from nerves to muscle cells are reduced, with LEMS being considered the most likely culprit.
Given the high suspicion of LEMS, clinicians wanted to test the patient for the presence of anti-VGCC antibodies to confirm the diagnosis, but owing to technical issues, this testing could not be completed. Regardless, the man was assumed to likely have LEMS and was treated with intravenous immunoglobulin (IVIG).
Researchers reported that the man had “a dramatic response” to this treatment, with his mobility improving substantially after about a week of IVIG.
His cancer also responded well to chemo, and after four cycles of treatment, his lymphoma was deemed to be in remission. However, his stay in the cancer unit was complicated by frequent infections and fevers, and six months after his initial cancer diagnosis, he ultimately died from complications of a severe infection.
According to researchers, this case highlights that “whichever the underlying cause of LEMS is, it is critical to be aware of it when evaluating weakness in a patient with a lymphoproliferative [immune cell overgrowth] illness of any age or stage.”
“We propose that any patient with a lymphoproliferative disease who complains of muscle weakness without a clear cause undergo a proper electrophysiological assessment for LEMS using one of the widely known diagnostic modalities before discharge,” they wrote.