Baseline ultrasound and FDG-PET/CT imaging in Merkel cell carcinoma

Zijlker, L.P.; Bakker, M.; Hiel, B. van der; Bruining, A.; Klop, W.M.C.; Zuur, C.L.; ... ; Akkooi, A.C.J. van (2022)

Article / Letter to editor

Background: Merkel cell carcinoma (MCC) is a cutaneous tumor with a high tendency to metastasize, and a significant proportion of patients have metastases at first presentation. This study aims to determine the value of baseline ultrasound (US) and (18)fluorodeoxyglucose-positron emission tomography/computed tomography ((18)FDG-PET/CT) imaging in both patients with clinically localized MCC (Stage I/II) and patients who present with palpable lymph nodes (Stage III). Methods: This retrospective cohort included 135 MCC patients who underwent baseline US (with fine needle aspiration cytology (FNAC)) and/or FDG-PET/CT imaging between 2015 and 2021. Results: Of the 104 patients with clinically localized disease, 48% were upstaged to Stage III and 3% to Stage IV by imaging or sentinel lymph node biopsy (SLNB). FDG-PET/CT imaging identified regional metastases in 23%, while US with FNAC identified regional metastases in 19%. SLNB was performed in 56 patients, of whom 57% were upstaged to Stage III. Of the 31 patients who presented with palpable lymph nodes, 16% were upstaged to Stage IV by FDG-PET/CT imaging. Conclusion: Baseline imaging frequently upstages Stage I/II MCC patients to Stage III, both by US and FDG-PET/CT, Stage IV disease is rarely identified. Patients who present with palpable nodes are frequently upstaged to Stage IV by FDG-PET/CT imaging.

• baseline imaging
• FDG-PET
• CT
• Merkel cell carcinoma
• ultrasound

• All authors: Zijlker, L.P.; Bakker, M.; Hiel, B. van der; Bruining, A.; Klop, W.M.C.; Zuur, C.L.; Wouters, M.W.J.M.; Akkooi, A.C.J. van
• Date: 2022-12-27
• Journal: Journal of Surgical Oncology
• DOI: doi:10.1002/jso.27193