Merkel cell carcinoma of the eyelid: management and prognosis

Abstract

Importance: The literature on Merkel cell carcinoma (MCC) of the eyelid remains scarce, and there has yet to be a study using the most up-to-date TNM staging system for this rare but aggressive tumor.

Objective: To analyze the TNM stage, management, and outcomes of patients with MCC of the eyelid.

Design, setting, and participants: Retrospective case series of 21 patients from 5 tertiary referral centers in the United Kingdom and Australia with primary MCC of the eyelid presenting at a median age of 77 years, with median follow-up of 54 months. Tumors were staged according to the American Joint Committee on Cancer, 7th edition, TNM criteria for eyelid carcinoma and MCC.

Main outcomes and measures: TNM stage, treatment modalities, and clinical outcome.

Results: The eyelid carcinoma TNM stages were T2aN0M0 for 5 patients, T2bN0M0 for 7 patients, T3aN0M0 for 4 patients, T3bN0M0 for 3 patients, T2bN1M0 for 1 patient, and T3aN1M0 for 1 patient. The MCC TNM stages were T1N0M0 for 12 patients, T2N0M0 for 7 patients, T1N1M0 for 1 patient, and T2N1M0 for 1 patient. One patient had a sentinel lymph node biopsy, and 8 patients underwent head/neck imaging. Eighteen patients underwent a wide local excision, 12 with a paraffin section and 6 with a frozen section. Two patients underwent Mohs surgery, 1 of whom required an orbital exenteration. Twelve patients (57%) received adjuvant radiotherapy, and 2 patients received chemotherapy. The local recurrence rate was 10%, the regional nodal recurrence rate was 10%, and the distant metastatic recurrence rate was 19%. The lowest T category tumor metastasizing to both regional nodes and distant locations was a T2a (eyelid TNM)/T1 (Merkel TNM) tumor measuring 8 mm. Two patients with T3a (eyelid TNM)/T2 (Merkel TNM) tumors died of metastatic MCC.

Conclusions and relevance: The majority of patients with MCC of the eyelid present with localized eyelid disease of T category T2 (eyelid TNM)/T1 (Merkel TNM). A wide local excision with margin control remains the mainstay of treatment, whereas the use of radiotherapy is institution specific. Tumors with a low T category are associated with regional nodal and distant metastatic disease. It may therefore be reasonable to consider a sentinel lymph node biopsy or strict regional lymph node surveillance for all MCCs of the eyelid, regardless of T category or size.