Abstract
BACKGROUND: Bladder cancer is one of the most common cancers worldwide, and urothelial carcinoma is the most common form of bladder cancer. Gastric metastasis of urothelial carcinoma of the bladder is a rare condition. Cystoscopy plays an important role in the diagnosis of bladder cancer; however, it is an invasive procedure that may affect the patient's prognosis and does not allow for the observation of cancer infiltration and metastasis. Therefore, non-invasive imaging is increasingly becoming the most appropriate method for the diagnosis and follow-up of urothelial carcinoma. CASE PRESENTATION: A 51-year-old female patient presented with pain in the lower abdomen and lower back for more than 2 months. This was a case of bladder urothelial carcinoma with gastric metastases, confirmed by pathology using dual-layer detector computed tomography (CT) spectral multiparametric imaging. The stage of the cancer was cT3N+M1b IVB, and the dimensions were 11.6 mm×42.2 mm×44.4 mm. The energy spectrum multiparameter image shows good consistency in the quantitative measurement of multiple nodules on the gastric wall and bladder wall masses (single energy 40 keV-CT value, iodine concentration, effective atomic number), and the spectral curve runs basically consistent. After 5 months of chemotherapy, the slope values of the spectral curve were 3.74 and 3.09 in the initial and follow-up spectral CT scans, respectively, reflecting the improvement of bladder wall lesions after treatment. CONCLUSIONS: The present case is a very rare case of bladder urothelial carcinoma with gastric metastasis. We applied multi-parameter quantitative indicators of spectral CT to more accurately show the homology characteristics of gastric metastasis and bladder cancer, and also reflected the different sources of cystic lesions in the left adnexal region from bladder cancer and gastric metastasis. Spectral CT has a promising application prospect in detecting the homology of different lesions and diagnosing urothelial gastric metastasis carcinoma.