Hepatic Echinococcosis as an Incidental Finding in a Patient With a Perforated Gastric Ulcer: A Case Report.

Echinococcosis is a zoonotic helminth infection with global distribution and a large public health impact. In Brazil, cases are traditionally associated with the Southern region, but mortality records show a substantial proportion of cases occurring in the Northeast, supporting underrecognition outside historically endemic areas. Herein, we report a case of a 67-year-old man who presented in early April 2025 with an acute abdomen due to a perforated gastric ulcer. He reported childhood exposure to sheep and dogs in rural Paraíba. Computed tomography (CT) demonstrated pneumoperitoneum and an incidental calcified hepatic cystic lesion in segment VII. Emergency laparotomy confirmed the perforated gastric ulcer, and the defect was repaired with ulcerorrhaphy and an omental patch. The hepatic lesion was excised en bloc with an intact cyst wall. The cyst was not opened or aspirated, and no spillage was observed. Histopathology demonstrated features consistent with cystic echinococcosis (CE). Albendazole was initiated and titrated to a maintained regimen of 400 mg orally twice daily. Serology was requested, and results were not available at the time of writing this report. Follow-up CT showed complete resection with no abdominal collections or evidence of dissemination. Lower limb weakness after intensive care was observed and attributed to severe deconditioning and critical illness-related neuromuscular weakness. This case highlights that CE can be encountered unexpectedly during emergency surgery in non-endemic urban settings and underscores the importance of safe intraoperative handling, clear operative documentation, and structured follow-up.