Anti-amphiphysin antibody-associated paraneoplastic brainstem encephalitis with pruritus and dysphagia as the first symptoms: A case report

RATIONALE: Anti-amphiphysin antibodies are uncommonly detected in paraneoplastic neurologic syndromes (PNS), especially in patients with small cell lung cancer. Here, we report the first case of anti-amphiphysin antibody-associated PNS with pruritus and dysphagia as the first complaints. PATIENT CONCERNS: The patient was a 58-year-old man who sought medical advice with a chief complaint of dysphagia and the lung occupancy. We found that he had developed progressive pruritus several months ago. DIAGNOSES: In the outer basal segment of the right lung lower lobe, PET-CT revealed small occupancies with hypermetabolism. Later, the pathology showed small cell lung cancer. And anti-amphiphysin antibodies were detected in serum. Above all, the patient’s symptoms improved significantly after antitumor treatment. Even neither of the 2 cranial enhancement MRIs showed any meaningful imaging signs, the above evidence could confirm the diagnosis of PNS. INTERVENTIONS: The chemotherapy regimen was etoposide 0.1g d1-3+cisplatin 40 mg d1-3 (q3w). Paroxetine 20 mg/day was given to relieve the itching. OUTCOMES: After the treatment, the Watian water swallowing test dropped from grade 5 to grade 1, the intense itching also became tolerable. LESSONS: Clinicians should consider diagnoses other than anxiety states or esophageal cancer in a patient with pruritus and dysphagia, such as PNS.