Broida Samuel E, Chen Xiao T, Baum Christian L, Brewer Jerry D, Block Matthew S, Jakub James W, Pockaj Barbara A, Foote Robert L, Markovic Svetomir N, Hieken Tina J, Houdek Matthew T
Department of Orthopaedic Surgery, Mayo Clinic, Rochester, Minnesota, USA.
Department of Dermatology, Mayo Clinic, Rochester, Minnesota, USA.
J Surg Oncol. 2022 Nov;126(6):1080-1086. doi: 10.1002/jso.27010. Epub 2022 Jul 9.
Merkel cell carcinoma (MCC) is a rare, aggressive cutaneous malignancy that usually occurs in the head/neck or extremities. However, there are reports of MCC developing in the lymph nodes or parotid gland without evidence of a primary cutaneous lesion.
We reviewed 415 patients with biopsy-proven MCC. Patients with MCC of unknown primary (n = 37, 9%, MCCUP) made up the study cohort. The primary endpoints of the study were rate of recurrence, disease-free survival, and overall survival.
Patients with MCCUP presented with tumors in lymph nodes (n = 34) or parotid gland (n = 3). Nodal disease was most commonly detected in the inguinal/external iliac (n = 15) or axillary (n = 14) regions. The mean age at diagnosis was 70 years and 24% were female. Patients presented with distant metastases in 24.3% of cases. Patients with stage IIIA disease treated with regional lymph node dissection (RLND) had a lower risk of disease recurrence (hazard ratio 0.26, p = 0.046). Recurrence-free survival was 59.3% at 5 years. Disease-specific survival was 63.3% at 5 years.
Patients with MCCUP have a high risk of recurrence and mortality. The optimal treatment for MCCUP has yet to be elucidated, although therapeutic RLND appears beneficial for these patients.
默克尔细胞癌（MCC）是一种罕见的侵袭性皮肤恶性肿瘤，通常发生于头颈部或四肢。然而，有报道称MCC可在淋巴结或腮腺中发生，而无原发性皮肤病变的证据。
我们回顾了415例经活检证实为MCC的患者。原发性不明的MCC患者（n = 37，9%，MCCUP）构成了研究队列。该研究的主要终点为复发率、无病生存期和总生存期。
MCCUP患者的肿瘤出现在淋巴结（n = 34）或腮腺（n = 3）。淋巴结疾病最常见于腹股沟/髂外（n = 15）或腋窝（n = 14）区域。诊断时的平均年龄为70岁，24%为女性。24.3%的病例出现远处转移。接受区域淋巴结清扫术（RLND）治疗的IIIA期疾病患者疾病复发风险较低（风险比0.26，p = 0.046）。5年无复发生存率为59.3%。5年疾病特异性生存率为63.3%。
MCCUP患者有较高的复发和死亡风险。尽管治疗性RLND似乎对这些患者有益，但MCCUP的最佳治疗方法尚未阐明。
