Management of Merkel Cell Carcinoma of the Digits, Hand, and Wrist.

Introduction: Merkel cell carcinoma (MCC) is a rare and often lethal cancer, with few cases presenting on the hand and digits. Treatments such as ray amputation can drastically impact quality of life and the existing literature is inconclusive. This systematic review evaluates the comprehensive management of surgically treated patients with MCC involving the digits, hand, and wrist. Methods: Following PRISMA guidelines, Medline and EMBASE were searched for studies reporting MCC of the digits, hand, and wrist. Given the heterogeneity of the reported data, no meta-analysis was performed; results are reported descriptively as counts/proportions among cases with available data. Results: Forty-two observational studies were included. Twenty-two reported MCC of the digit (25 lesions), of which 15/25 (60%) underwent wide local excision (WLE) and 10/25 (40%) ray amputation. Among cases with available data, recurrence occurred in 2/7 (29%) after WLE and 2/8 (25%) after ray amputation, with MCC-related mortality in 2/9 (22%) of each. Nineteen studies reported MCC of the hand/wrist (n = 19), of which 17/19 (89%) underwent WLE, with recurrence in 7/14 (50%) and MCC-related mortality in 2/12 (17%). Adjuvant radiotherapy and chemotherapy were used in 10/19 (53%) and 4/19 (21%), and nodal management included sentinel lymph node biopsy in 5/13 (38%) and dissection in 4/13 (31%). An additional aggregate cohort of 25 patients was summarized separately. Conclusion: Evidence for MCC of the digits, hand and wrist is limited to case reports and small series with heterogeneous staging/treatment and incomplete reporting. Further evidence is needed to determine optimal management in this region.