Primary Intrahepatic Mesothelioma: Case Series and Systematic Review of Literature.

Background: Primary intrahepatic mesothelioma (PIHMM) has been rarely reported. Its typical clinical presentation, radiological features and pathology have not been defined. Here, we aimed to summarize its diagnosis and treatment.

Methods: We conducted a retrospective analysis of three cases of PIHMM in the First Affiliated Hospital of Zhejiang University School of Medicine and reviewed the current literature to investigate the clinical and pathological characteristics and prognosis of PIHMM.

Results: Based on our case series and the literature, the mean age of PIHMM was 59.7 (41-83) years. Most patients present with nonspecific symptoms such as abdominal pain, fever, weight loss and weakness. On imaging, PIHMM usually presented as a solid, heterogeneous soft tissue mass with irregular margins and significant enhancement of the margins in the arterial phase. Immunohistochemical markers such as calretinin, cytokeratin (CK)5/6, D2-40, WT-1, mesothelin CK and vimentin may be useful for diagnosis. The 3-year relapse-free survival rate (RFS) was 51.85%, the 3-year overall survival (OS) rate was 83.33% and the 3-year postoperative overall survival rate was 100%.

Conclusion: PIHMM can only be diagnosed by careful postoperative pathology, because of its nonspecific clinical presentations, serological indicators or imaging features. Immunohistochemical staining is very useful to distinguish this tumor from other liver tumors. Surgery is the mainstay of treatment.