Hepatoid adenocarcinoma (HAC) is a rare neoplasm with aberrant hepatocellular differentiation. HAC occurs in extrahepatic organs such as the gastrointestinal tract, testes, ovaries, and lungs and frequently produces alpha-fetoprotein. A 69-year-old patient was diagnosed clinically with T2aN0M0, stage IB, non-small cell lung carcinoma. Because the tumor showed tight adhesion to the chest wall, we performed left upper lobectomy, combined resection of the 3rd and 4th ribs, and lymph node dissection. Pathological examination confirmed the diagnosis of HAC of the lung (pathological T2aN0M0, stage IB), and four courses of cisplatin and gemcitabine were administered as adjuvant chemotherapy. Genetic analysis of the epidermal growth factor receptor showed wild type. Preoperative serum alpha-fetoprotein level, a useful marker of disease progression, was elevated to 4497 ng/ml, decreasing within the normal range by about 3 months postoperatively. The patient remains alive without recurrence as of 51 months after surgery.
Keywords: Alpha-fetoprotein (AFP); Hepatoid adenocarcinoma; Lung neoplasms.