Primary intrahepatic mesotheliomas: A case presentation and literature review

INTRODUCTION: Primary Intrahepatic mesotheliomas are malignant tumors arising from the mesothelial cell layer covering Glisson's capsule of the liver. They are exceedingly rare with only fourteen cases reported in the literature. They have nonspecific signs and symptoms and need a high index of suspicion and an extensive workup prior to surgery. Surgery remains the mainstay of treatment. PRESENTATION OF CASE: 48 year old male presented with a 3 months history of abdominal pain, productive cough, anemia and weight loss. He had no history of asbestos exposure. A computed tomography scan and magnetic resonance study demonstrated a heterogeneous subscapular mass within the dome of the right hepatic lobe measuring 11.3 × 6.1 cm involving the diaphragm. Combined resection of the liver and diaphragm was performed to achieve negative margins. Pathology demonstrated an epithelioid necrotic intrahepatic mesothelioma that stained positive for calretinin, CK AE1/AE3, WT-1, D2-40 and CK7. DISCUSSION: Primary intrahepatic mesotheliomas originate from the mesothelial cells lining Glisson's capsule of the liver. They predominantly invade the liver but may also abut or involve the diaphragm. Surgery should include a diagnostic laparoscopy to rule out occult disease or diffuse peritoneal mesothelioma. Complete resection with negative margins should be attempted while maintaining an adequate future liver remnant. Attempts at dissecting the tumor off the involved diaphragm will result in excessive bleeding and may leave residual disease behind. CONCLUSION: Intrahepatic mesotheliomas are rare peripherally-located malignant tumors of the liver. They require a high index of suspicion and a comprehensive workup prior to operative intervention.