A rare neurological odyssey: Gastric adenocarcinoma and leptomeningeal carcinomatosis – A Peruvian case study

Background: Leptomeningeal carcinomatosis involves the diffuse infiltration of neoplastic cells in the central nervous system, affecting 5-8% of leukemia, breast, and lung cancer cases. Gastric cancer instances are rare, mostly in poorly differentiated adenocarcinomas. We report the first Peruvian case, featuring gastric adenocarcinoma. Case Presentation: A 51-year-old woman presented with severe headache, vomiting, dizziness, blurred vision, tinnitus, bradyphrenia, reduced verbal fluency, sixth cranial nerve paresis, and non-reactive anisocoric pupils. Pleocytosis was found, with positive cytology for metastatic adenocarcinoma in cerebrospinal fluid, and a solid gastric mass defined as poorly differentiated adenocarcinoma. Due to her condition, the patient did not receive oncological management, evolving unfavorably and passing away twenty days later. Leptomeningeal carcinomatosis should be considered in patients with advanced cancer and meningeal symptoms. It is more predominant in women, with an average age of 53.84 years. Clinical presentation of leptomeningeal carcinomatosis varies, and diagnosis involves neuroimaging and cerebrospinal fluid cytology. Prognosis is unfavorable, often leading to fatality. Treatment protocols lack standardization, and personalized approaches, including targeted and systemic therapies, are explored for improved outcomes. The exceptional aspect of our case lies in the unique diagnosis of an abdominal tumor following the manifestation of neurological symptoms. Conclusion: It is important to suspect this condition among the causes of meningitis, especially in the presence of an underlying malignancy.