Staging evaluation and initial management of clinically negative lymph nodes in locoregional Merkel cell carcinoma

MCC: Merkel cell carcinoma; SLNB: sentinel lymph node biopsy; SLN: sentinel lymph node; RT: radiation therapy.

* Both RT and completion lymph node dissection are appropriate options because they are similarly effective in clearing the nodal bed in this population. Selection of therapy is based upon institutional experience, patient preference, and the potential risks and toxicities of each treatment approach

¶ Definitive RT is delivery of radiation as the sole modality for local disease control.

Δ Reasons for false-negative biopsy results include wide local excision of the primary tumor prior to biopsy; prior history of lymph node excision or nodal melanoma; multiple lymph node basins (eg, MCC of the head and neck or midline-trunk); or technical issues with tissue processing.

◊ Elective RT is delivery of radiation to an uninvolved regional lymph node area at risk for microscopic disease.

§ Observation is an appropriate alternative for those who do not undergo SLNB due to comorbidities and have a primary tumor at low risk for recurrence or metastasis. (≤1 cm with no lymphovascular invasion).

¥ For details on routine posttreatment surveillance, refer to UpToDate content on staging, treatment, and surveillance of locoregional MCC.