Infiltrative invasion of the diaphragm: an uncommon manifestation of recurrent hepatocellular carcinoma

Purpose: To report on infiltrative invasion of the diaphragm, an uncommon manifestation of recurrent hepatocellular carcinoma (HCC), and evaluate its clinical significance. Methods: Using the term “diaphragm” or “diaphragmatic” and “invasion” or “involvement,” we searched for patients in the database of radiologic reports of liver computed tomography or magnetic resonance imaging performed between 2012 and 2016 at our institution. Nine patients with infiltrative invasion of the diaphragm due to recurrent HCC were included. Their clinical and imaging findings were evaluated. Results: The median age of patients at the time of diagnosis was 68 years (range, 40 to 73). There were eight men and one woman. Imaging findings of infiltrative invasion of the diaphragm revealed diffuse thickening with enhancement involving a part of the diaphragm. The median interval between initial manifestation on imaging and radiologic diagnosis of infiltrative invasion of the diaphragm was 6.8 months (range, 3.4 to 18.6). In two of three patients who underwent surgical resection, tumors of the diaphragm were controlled without recurrence. In six patients except for one patient who was not followed up, tumors recurred at the resection site or diaphragm tumors showed a partial response or disease progression. Conclusion: Infiltrative invasion of the diaphragm by recurrent HCC manifested with diffuse thickening and diaphragm enhancement on radiologic imaging. A good prognosis can be expected only in patients who are diagnosed early and undergo surgical resection.