Now you see me: lights on Merkel Cell Carcinoma.

Abstract

Merkel Cell Carcinoma (MCC) is a rare primary cutaneous cancer with aggressive behaviour and poor prognosis. Although MCC cells express somatostatin receptors (SSTR), SSTR-targeted PET/CT is not routinely performed in clinical practice. In contrast, the use of [¹⁸F]FDG PET/CT is more widespread and its prognostic role is well established. We present the case of an MCC patient suspected recurrence who underwent restaging with both [¹⁸F]FDG and [⁶⁸ Ga]Ga-DOTA-TOC PET/CT. [¹⁸F]FDG PET/CT showed pathological uptake only in mediastinal lymph nodes, but SSTR imaging also revealed multiple liver and skeletal metastases, leading to significant disease upstaging and relevant changes in the therapeutic management.