Multimodal Detection of a Minute Uterine Cornual Lesion in Cervical Clear Cell Carcinoma

Cervical clear cell carcinoma (CCC) is a rare human papillomavirus (HPV)-independent adenocarcinoma. A 73-year-old woman presented with postmenopausal bleeding. Ultrasonography demonstrated a cervical mass and a 5.0 × 5.0 mm right cornual nodule. On 3.0-T magnetic resonance imaging (MRI), the cornual lesion measured 5.2 × 5.3 mm and, like the cervical tumor, showed high signal intensity on diffusion-weighted imaging (b = 1000 s/mm²). ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) demonstrated intense uptake in the cervical mass (30.6 × 29.2 × 41.2 mm; SUV_max 10.4) and in the spatially separate right cornual nodule (5.2 × 5.1 mm; SUV_max 14.6), without FDG-avid nodal or distant metastatic disease. The concordant identification of the cornual lesion by ultrasonography, MRI, and PET/CT prompted multidisciplinary reassessment and radical hysterectomy to obtain definitive pathological characterization of both lesions. Histopathology demonstrated clear cell carcinoma at both sites; however, because molecular, genomic, or clonality analyses were not performed, their biological relationship remains uncertain. All 30 examined lymph nodes and the surgical margins were negative. The cervical primary was staged as pT1b3 pN0 cM0 (FIGO 2018 stage IB3). The patient received four cycles of postoperative chemotherapy with paclitaxel plus cisplatin. At 14 months after surgery, gynecological examination and pelvic MRI showed no evidence of recurrence. This case highlights the complementary roles of ultrasonography, MRI, and ¹⁸F-FDG PET/CT in characterizing a minute spatially separate uterine lesion while underscoring the need for cautious interpretation when the relationship between lesions cannot be established.