Overlooked parahiatal hernia: diagnostic challenges and implications of a case report

Parahiatal hernias (PHHs) comprise of less than 1% of all diaphragmatic hernias and are frequently mistaken for paraesophageal hernias due to their close anatomical proximity to the esophageal hiatus. Unlike classic hiatal hernias PHH herniate laterally through a defect in the left crus separated from the esophageal hiatus. Because of their rarity and diagnostic ambiguity, PHHs are underrecognized and often incidentally found during imaging or endoscopy. The etiology can be congenital or acquired with known risk factors including trauma, prior esophageal and abdominal surgeries, or diaphragmatic weakness.

We present a case of a 73-year-old female with a history of small cell lung malignancy treated with thoracic radiation who was admitted for symptomatic anemia. While being evaluated for odynophagia and suspected esophagitis an esophagogastroduodenoscopy (EGD) initially revealed a paraesophageal hernia. However, upon further review of the EGD images it was diagnosed as a PHH. Notably, a previous EGD two years prior had shown no such hernia suggesting an acquired defect possibly radiation induced. The patient's symptoms improved with medical management for esophagitis and no surgical intervention was required due to the hernia's small size and absence of complications.

This case emphasizes the importance of distinguishing PHH from other hiatal hernias, particularly in elderly patients with complex medical histories. Misclassification may lead to inappropriate management especially if surgical repair is needed. While congenital and traumatic causes are well established this case introduces radiation therapy as a potential contributing factor to acquired PHH, a connection not previously documented in literature. Clinicians should maintain a high index of suspicion for PHHs during endoscopic or radiologic evaluation, especially when the hernia anatomy appears atypical. Early and accurate diagnosis is essential to guide appropriate treatment and prevent unnecessary surgical intervention if not indicated.