Port-Site Metastases in Incidentally Detected Carcinoma Gall Bladder: Role of 18F-FDG PET/CT and Patient Outcome.

Abstract

Incidentally detected gall bladder carcinoma (IGBC) is occasionally encountered after cholecystectomy for benign gall bladder disease. Rarely these patients may present with port-site metastases (PSM) in follow-up. We retrospectively assessed the role of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET/CT) in them. We aimed to determine the clinical outcome and correlate the survival based on FDG PET/CT findings. We did a single-center retrospective study in IGBC patients presented with histopathologically proven PSM. FDG PET/CT was done for restaging. The metastatic burden was evaluated. Survival after PSM and overall survival (OS) were assessed in different disease groups. A total of 22 patients (51.86 ± 12.04years) were included in the study. The mean interval between LC and PSM was 336.7 ± 501.9days. On FDG PET/CT, isolated single PSM was noted in 21 (95.5%) patients. Apart from PSM, abdominal lymph nodes, GB fossa lesion, and liver metastases were noted in the 10 (45.5%), 6 ( 27.3%), and 7 (31.8%) patients, respectively. FDG PET/CT revealed intra-abdominal disease and visceral metastasis in 11 (50%) and 10 (45.5%) patients. Nineteen (86.4%) patients died in follow-up with a median survival of 328.50 (225.25-804.0) day after PSM. Median OS after LC was 687.00 (362.50-1047.0) days. Patients with PSM plus disease (432.0days, 255.9-608.1), extra-abdominal metastases (400.0days, 316.9-483.1), and visceral metastases (400.0days, 296.2-503.8) had significantly lower OS compared to isolated PSM (1763days, p = 0.013), the intra-abdominal disease (996.0days, 753.2-1238.8, p = 0.0340), and non visceral metastasis (807.0days, 467.5-1146.4, p = 0.037). IGBC presenting as PSM is a distinct clinical entity. FDG PET/CT as functional imaging evaluates the local and metastatic disease burden. There is significantly lower survival in patients with PSM plus disease, extra-abdominal metastases, or visceral metastases. FDG PET/CT was an important prognostic marker in these patients and could help in management.