Added value of contrast-enhanced ultrasound (CEUS) in the diagnosis of primary retroperitoneal serous adenocarcinoma: a case report

BACKGROUND: Primary retroperitoneal serous adenocarcinoma (PRSA) is a rare malignant disease. Given the rarity of the disease, the imaging features of PRSA are unclear. Contrast-enhanced ultrasound (CEUS) also plays an important role in the evaluation of the differential diagnosis of retroperitoneal lesions. CASE PRESENTATION: We report the case of a 62-year-old woman of with increased CA125 levels for 1 year who was referred to our hospital. After conducting contrast-enhanced computed tomography and magnetic resonance imaging, the mass was misdiagnosed as a chocolate cyst. After transvaginal ultrasound (TUS) combined with CEUS, cystadenocarcinoma was considered as the initial diagnosis. Pathology results confirmed PRSA as the final diagnosis. CONCLUSIONS: CEUS features of PRSA are reported for the first time based on this case, potentially aiding in the differential diagnosis of this rare entity before surgery.