238 A Rare Case of Primary Gastric Choriocarcinoma. (11th January 2018)

• Record Type: Journal Article
• Authors: Raza, Roshan; Mannan, Abul Ala Syed Rifat; Yuan, Songyang
• Is Part Of: American journal of clinical pathology. Volume 149(2018)Supplement 1
• Page Start: S101
• Page End: S102
• Publication Date: 2018-01-11
• Subjects: Diagnosis, Laboratory -- Periodicals; Pathology -- Periodicals; 616.07
• DOI: 10.1093/ajcp/aqx123.237
• Languages: English
• ISSNs: 0002-9173

Abstract

Abstract: Choriocarcinoma is a β-hCG-producing tumor of the trophoblastic or totipotent germ cells that develops primarily in the ovary and testis. Primary gastric choriocarcinoma (PGC) is extremely rare, and most such cases are not correctly diagnosed prior to resection. Most PGCs have been reported to possess an adenocarcinoma component and pure PGC is extremely rare. We report a PGC in a 62-year-old man who presented to the emergency department with epigastric pain, nausea, generalized weakness, fever. and chills. His past medical history was significant for chronic hepatitis B virus infection and statue post chemoradiation therapy for gastric adenocarcinoma with celiac lymph node metastasis diagnosed 6 months ago. The patient subsequently underwent partial gastrectomy, revealing a 3.5 cm hemorrhagic ulcerated mass along the lesser curvature. Histology showed dimorphic mixture of mononucleated cytotrophoblasts and multinucleated syncytiotrophoblasts with extensive necrosis and hemorrhage. Tumor extended to gastric serosa with 16 positive lymph nodes in the perigastric and celiac region. For the definite diagnosis of choriocarcinoma, immunohistochemical study was performed, β-hCG, CK7 and p63 (focally) were positive, and CK20 was negative. No adenocarcinoma was seen in the entire submitted tumor. The original biopsy was re-evaluated and revealed mainly moderately differentiated adenocarcinoma (90%), which exhibited positive immunostaining for CK20 and negative immunostaining for β-hCG, CK7, and p63. The remaining 10% of tumor was a pleomorphic component with rare syncytiotrophoblast-like cells, which showed positive immunostaining for CK20, β-hCG (focally), and p63 (focally), and negative immunostaining for CK7. The original biopsy was consistent with adenocarcinoma with focal choriocarcinoma component. The current case highlights the importance of correct diagnosis of choriocarcinoma when it occurs outside its usual confines.