Primary gastric choriocarcinoma: a rare and aggressive gastrointestinal malignancy.

A 40-year-old male with no previous medical history presented to emergency department with a 2-week history of progressive dyspnea. He also described night sweats and weight loss (15 kg) during the last 3 months. Thoraco-abdominal computed tomography showed multiple bilateral lung nodules associated with supra-clavicular, hilar and peri-esophageal lymphadenopathies and gastric parietal thickening. These imaging features were suggestive of primary gastric cancer with lung and lymph node metastases. Therefore, he undergone upper digestive endoscopy that showed a large ulcerated protruding lesion at the greater curvature of the body suggestive of malignancy. Gastric biopsies of the lesion confirmed a solid neoplasia constituted by solid nests and sheets of highly pleomorphic, bizarre cells with cytotrophoblastic and syncytiotrophoblastic differentiation that, on immunohistochemistry, stained positive for β-HCG, SALL-4 and glypican-3. CT-guided biopsy of lung nodules revealed malignant cells with similar histopathological and immunohistochemical features. Elevated serum alpha-fetoprotein and β-HCG were also detected. Clinical and ultrasound examination were negative for testicular masses. These findings were consistent with a primary gastric choriocarcinoma presenting with lung and lymph node metastases (stage IV). Although chemotherapy was started, the patient evolved unfavorably and died after 9 months. Primary gastric choriocarcinoma is a rare and aggressive gastrointestinal malignancy. This case demonstrates its rapid growth rate and high metastatic potential that may lead to symptoms from secondary involvement of distant organs.