A retroperitoneal bronchogenic cyst mimicking adrenal tumour in an adult: is differential diagnosis truly possible?

Bronchogenic cysts are developmental abnormalities of the primitive foregut resulting from aberrant budding from the ventral diverticulum. A retroperitoneal position for a bronchial cyst is extremely unusual and should be differentiated from other neoplastic lesions. Although histologically they can be differentiated from other lesions, bronchial cysts may show various pathological patterns of differentiation that may cause confusion in differentiating them from cystic teratomas. This is a case of a retroperitoneal bronchogenic cyst featuring uncommon histological findings, which raises the question whether these benign lesions can always be accurately differentiated from teratomatoid cystic neoplasms.