Overexpression of beta-
human chorionic gonadotropin (β-hCG) is frequently associated with germ cell tumours, especially
choriocarcinoma. Ectopic secretion of β-hCG by
non-small cell lung cancer is exceptional. We present an exceedingly rare case of pulmonary
adenocarcinoma that secretes β-hCG. Our patient is a 62-year-old postmenopausal woman, a nonsmoker, who presented with a six-month history of progressive dyspnoea, associated with decreased appetite and significant
weight loss. Her serum β-hCG was very high (11211.9 mIU/ml), which prompted investigations to exclude germ cell tumour. Radiological imaging revealed a 10-cm right lung mass with adrenal
metastasis. No other focal lesions were detected. Microscopy of the lung biopsy specimen showed replacement of normal lung tissue by sheets of malignant cells, forming vague glands in some areas. Immunohistochemically, the malignant cells showed focal immunopositivity for
thyroid transcription factor 1 (TTF-1), napsin A,
cytokeratin 7 (CK7) and β-hCG. A diagnosis of β-hCG-secreting pulmonary poorly differentiated
adenocarcinoma was rendered. Serum β-hCG level decreased significantly to 168.6 mIU/ml after the first cycle of
chemotherapy. In conclusion, β-hCG expression in
lung cancer should be recognised to facilitate prompt diagnosis and initiation of appropriate intervention.