Merkel-cell carcinoma: preoperative clinical diagnosis and therapeutic implications

Abstract

The authors report the personal experience of some patients undergoing surgery for carcinoma of Merkel and discuss the diagnosis and therapeutic approach guided by literature and international guidelines. Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine tumour, which prefers the Caucasian race in adulthood. Approximately 78% of patients are over than 59 years, the most common location is at the level of the head and neck (50.8%) and less frequently in the limbs (33.7%). The literature is discordant about the causes and risk factors for this cancer. In fact, some authors describe major risk factor the immunosoppression, still others see prolonged exposition to UV radiation increases the risk for the onset of this tumor. Metastasizes early to the skin (28%), the lymph nodes (27%), liver (13%), lung (10%), bone (10%) and encephalon (6%), and may recur both locally (30-60%) and both locoregional (40-73%). Our experience confirms the difficulty of preoperative clinical diagnosis and a correct therapeutic approach to Merkel cell carcinoma for the lack of specific characteristics as first clinical assessment, which may keep the suspect nature. International guidelines provide a wide excision (3 cm in largeness and 2 cm in depth) to reduce the risk of disease recurrence, preferring adjuvant chemotherapy not radiotherapy. For lesions of stage I-II over the wide excision also regional lymphadenectomy is performed or, more rarely, the technique of sentinel lymph node.