Acute lethargy in a young woman due to latent disseminated cancer mimicking bacterial meningitis: A diagnostic pitfall

Abstract Leptomeningeal carcinomatosis is an atypical behavior of cancer as a consequence of infiltration of malignant cells into the leptomeninges. Leptomeningeal carcinomatosis may share similar clinical manifestations with other etiologies involving the leptomeninges such as infectious meningitis or meningoencephalitis. We present a diagnostic pitfall of acute leptomeningeal carcinomatosis from a latent gastric cancer in a 28-year-old woman presenting with being rapidly comatose and an initial misdiagnosis as bacterial meningitis. This case report aims to raise red flags suggesting that when progressive neurological deterioration mimicking infectious meningitis but with poor responses to empirical antimicrobial therapy are encountered in healthy young individuals, the rare possibility of leptomeningeal carcinomatosis should be considered in the differential diagnosis even if patients have no known malignancy. Cerebrospinal fluid cytology along with gadolinium enhancement magnetic resonance imaging may be critical in the timely diagnosis and management of these patients with overlapping clinical features. Case report. A 28-year-old woman was admitted to the emergency department with a 5-day history of reduced consciousness, blurry vision, gait disturbance, and episodic focal seizures. Her past medical and family histories were unremarkable. 3 days before presentation, she had been admitted to a local hospital and received empiric antibiotics plus anticonvulsants therapy for suspected acute bacterial meningitis, but with no clinical improvement. On arrival, her vital signs were febrile temperature of 37.8 °C, pulse rate of 80 per minute, respiratory rate of 18 per minute, and blood pressure of 120/80 mmHg. Her conjunctivae were not icteric, clear breath sounds in auscultation, and regular cardiac sounds without pericardial friction rubs. Neurologic examination revealed lethargy with a Glasgow Coma Scale score of 13 (eye opening: 3, best verbal response: 4, and best motor response: 6), bilateral abducens nerve palsy with funduscopic papilledema, quadriparesis with a Medical Research Council scale of grade 3 ~ 4, and upper limb dysmetria according to the finger-nose-finger coordination test. Meningeal irritation signs were equivocal. Routine biochemical analyses and toxin screen were within normal limits except for a leukocytosis (white blood cell counts of 15,840/μL; reference value: 4500 ~ 11,000/μL) and an elevated C-reactive protein (0.64 mg/dL; referen