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A4018 - “Hepatoid Adenocarcinoma of the Lung with Normal Alpha-Fetoprotein Level”
Author Block: D. Ruiz Cerrato1, J. S. Wang Memoli2, W. Lee3; 1Medicine/Pulmonary and Critical Care, MedStar Washington Hospital Center, Washington, DC, United States, 2Medicine/Pulmonary, Medstar Washington Hospital Center, Washington, DC, United States, 3Pathology, MedStar Washington Hospital Center, Washington, DC, United States.
Introduction Hepatoid adenocarcinoma of the lung (HAL) is a rare extrahepatic tumor that resembles hepatocellular carcinoma (HCC). The most common is gastric (63-83%) and only about 5% originate in the lung. The majority of cases reported have been diagnosed in men and are associated with elevated alpha-fetoprotein (AFP). We present a case of a female patient with HAL with normal serum AFP. Case Description 69 year old female with seventy pack year smoking history was referred to our pulmonary service for left upper lobe (LUL) mass. Patient had been complaining of cough for over one month associated with dyspnea on exertion and weight loss. Chest CT demonstrated a mass measuring 5.7 x 4.3 x 5.7cm with mediastinal and hilar lymphadenopathy. Endobronchial ultrasound with fine needle aspiration was performed and pathology report demonstrated carcinoma with hepatoid features (positive for CK7 and HepPar-1 and negative for CK20, CK5/6, P63, TTF-1 stained tumor cell cytoplasm but not nuclei), AFP stain was equivocal and serum AFP was normal. Her course was complicated by post-obstructive pneumonia and repeat CT showed the LUL mass had increased in one month period to 8x8x5cm with no abdominal or pelvic metastasis (stage IIIA T3N1M0). Palliative radiation therapy was started as she was not a candidate for other treatment modality. Repeat imaging showed an adrenal lesion concerning for metastasis. Patient's status continued to decline and she was transitioned to hospice care. Discussion Pulmonary hepatoid carcinoma is rare with approximately twenty cases reported in the literature. HAL was initially described as an AFP- producing carcinoma, histological evidence of AFP producing cells and/or elevated serum AFP was essential for the diagnosis. Throughout the years the criteria has been modified and a few cases have reported normal AFP, requiring the diagnosis to be established by morphology and immunohistochemistry. Expression of certain proteins vary among different published cases and many report positivity for CK7 and HepPar-1. Negative nuclear TTF-1 helps differentiate from conventional adenocarcinoma of the lung. In general, HAL is considered to be associated with a poor prognosis and clinical stage represents a significant prognostic factor. Two reported cases of patients with negative AFP had a longer survival time. Our patient who was AFP negative unfortunately progressed from stage II to III in a few months and her poor performance limited her treatment options. Therapy so far is experimental and not well defined and further investigation is warranted.