Median Diaphragmatic Cyst Radiologically Consistent with a Mesothelial Cyst in a Young Adult: A Case Report

Diaphragmatic mesothelial cysts are rare, benign congenital lesions of the diaphragm, presumed to originate from coelomic remnants. Typically identified in pediatric populations, adult presentations – though uncommon – can pose diagnostic challenges due to vague or non-specific symptoms. We present the case of a 30-year-old African male with no prior imaging history, experiencing persistent epigastric pain exacerbated by deep inspiration. An inconclusive ultrasound was followed by a contrast-enhanced computed tomography scan, revealing a midline cystic lesion located adjacent to the posterior diaphragmatic pillar. This case highlights the importance of considering diaphragmatic mesothelial cysts in the differential diagnosis of chronic abdominal pain and details the characteristic imaging findings.