Hepatocellular Carcinoma (HCC) Metastasis to the Diaphragm Muscle: A Systematic Review and Meta-Analysis of Case Reports

Simple Summary Hepatocellular carcinoma (HCC) stands as a primary malignancy of the liver and represents a significant global health burden, particularly in regions where chronic hepatitis B and C infections prevail. Despite advancements in diagnostic techniques and therapeutic strategies, HCC continues to pose formidable challenges in clinical management due to its aggressive nature, frequent late-stage diagnosis, and metastasis to other organs. Although the incidence of metastasis to the diaphragm is low, this condition is one of few poor prognostic factors for HCC, making the early detection of diaphragm muscle involvement important in both primary and recurrent stages. The purpose of our study was to address two questions: (1) What symptoms or symptom clusters are reported among HCC patients with metastases to the diaphragm? (2) What risk factors for diaphragm muscle metastasis are present in HCC patients? Based on our findings, we conclude that the presence of hepatitis B and the localization of HCC cells in superior liver segments, particularly in the 8th liver segment, should be considered during the diagnostic process. Each patient in the reports presented with different symptoms, making it impossible to identify the leading symptom.Abstract The purpose of this study was to conduct a systematic review and meta-analysis of case reports presenting HCC spread to the diaphragm muscle and to determine possible risk factors for this condition. An extensive literature search was performed using the following electronic databases: MEDLINE, CINAHL, ScienceDirect, Google Scholar, and DOAJ. A total of 18 articles describing 27 hepatocellular carcinoma patients were included in this review. The presence of HCC cells in the superior liver segment is strongly associated with metastases to the diaphragm. Among the two types of diaphragm involvement by HCC cells, diaphragm infiltration occurs much more frequently than diaphragm adhesion. However, an HCC nodule in the 8th liver segment and a higher number of liver segments involved by HCC cells predispose patients to diaphragm adhesion. Hepatitis B is a risk factor for diaphragm metastases in recurrent HCC. The tumor diameter is not associated with HCC spread to the diaphragm muscle. We did not find specific symptoms reported by patients that could indicate HCC metastasis to the diaphragm muscle. The presence of hepatitis B and the localization of HCC cells in superior liver segments, especially in the 8th liver segment, should be take into consideration in the diagnostic process.