Metastatic mucinous adenocarcinoma in an inguinal hernia is a rare disease and the image findings of $^{18}F$-fluorodeoxyglucose ($^{18}F$-FDG) positron emission tomography (PET)/computed tomography (CT) are little known. Here, we introduce a 57-year-...
Metastatic mucinous adenocarcinoma in an inguinal hernia is a rare disease and the image findings of $^{18}F$-fluorodeoxyglucose ($^{18}F$-FDG) positron emission tomography (PET)/computed tomography (CT) are little known. Here, we introduce a 57-year-old man with metastatic mucinous adenocarcinoma in an inguinal hernia. On initial $^{18}F$-FDG PET/CT, hypermetabolism was observed in mucinous adenocarcinoma of the cecum, and adenocarcinomas of the transverse and ascending colon, respectively. Follow-up $^{18}F$-FDG PET/CT revealed newly developed multiple hypermetabolism in peritoneal seeding masses and nodules in the pelvic cavity and scrotum. Peritoneal carcinomatosis in the right pelvic side wall was extended to the incarcerated peritoneum and mesentery in the right inguinoscrotal hernia. $^{18}F$-FDG PET/CT was useful to reveal unexpected peritoneal seeding within the inguinal hernia. Also, this case demonstrated that metastatic mucinous adenocarcinomas had variably intense FDG uptake.