Lower motor neuron syndrome in a patient with HER2-positive metastatic breast cancer: A case report and review of the literature

Amyotrophic lateral sclerosis with coexisting cancer: a single-center study

This study investigated the occurrence of malignancy in a cohort of patients with amyotrophic lateral sclerosis (ALS). Forty-three consecutive ALS patients (mean age 61.3 years, 31 men/12 women) admitted between 2015 and 2019 were enrolled. Clinical, electrophysiologic and outcome features that differentiate cancer-associated ALS from classical ALS were investigated. ALS was associated with cancer in 5 (11.6%) patients. Two patients were diagnosed with non-small cell lung, one with endometrium, one with prostate and one with laryngeal carcinoma. One another patient was diagnosed with monoclonal gammopathy of unknown significance, but she did not develop cancer within 12-month follow-up duration. Two patients had a previous diagnosis of cancer before the diagnosis of ALS. In the remaining 3 patients, cancer was diagnosed at the same time or after the onset of ALS. There was no significant difference with respect to mean age of onset, sex, disease duration, clinical and electrophysiological features and outcome between patients with and without malignancy. None of the patients with cancer survived more than two years after the onset of ALS except one who was diagnosed with flail-leg syndrome before the diagnosis of non-small cell lung carcinoma. ALS is not accepted as a classical paraneoplastic neurological syndrome. Although the association of ALS and cancer seems coincidental, a careful investigation for an underlying cancer is important in patients with ALS. In our patient group with cancer-associated ALS, no distinguishing features were identified.

Paraneoplastic Encephalitis Associated with Locally Advanced Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer

Paraneoplastic neurologic diseases (PND) are rare but can occur in patients with common malignancies including breast cancer. In patients with hormone receptor (HR)-negative human epidermal growth factor receptor 2 (HER2)-positive breast cancer, PND have been reported in association with anti-Yo antibodies and with clinical presentation of paraneoplastic cerebellar degeneration. We describe the case of a woman with progressively altered mental status and seizures, ultimately requiring admission. Based on her clinical presentation, imaging findings, and evidence of neural-directed antibodies in her serum and cerebrospinal fluid, she was diagnosed with paraneoplastic limbic encephalitis (LE) due to an underlying HR-negative, HER2-positive breast cancer. She showed a transient response to immunosuppression but had more significant improvement after surgical resection and initiation of chemotherapy along with HER2-directed therapy. To the best of our knowledge, this is the first documented case of paraneoplastic LE in a patient with HR-negative, HER2-positive breast cancer likely caused by the production of an unclassified anti-neuronal antibody.