Merkel cell carcinoma (MCC) is a rare cutaneous cancer of neuroendocrine cell origin that occurs frequently on the head and neck. With a high incidence of local recurrence and regional and distant metastasis, it carries a poor prognosis. We performed a retrospective study to determine the prognostic implications of parotid gland metastasis in MCC of the head and neck. Our study population was made up of 14 patients—13 men and 1 woman, aged 62 to 87 years (mean: 75.9)—who underwent a parotidectomy for the diagnosis of MCC over a period of 10 years and 9 months. Ten patients had a primary skin lesion of the head and neck and 4 presented with a parotid mass and an unknown primary. In all, 13 of the 14 patients were found to have parotid involvement—either a direct extension of MCC into the gland or a positive intraparotid lymph node; some patients had both. All patients underwent tumor excision, and 10 underwent neck dissection. Eleven patients received adjuvant radiotherapy; none received adjuvant chemotherapy. Of the 10 patients who underwent a neck dissection, 6 were found to have a cervical lymph node metastasis on pathologic examination. Follow-up ranged from 1.3 to 39.2 months (mean: 12.4). Three patients were lost to follow-up shortly after surgery, although some information was available on 2 of them. At the final follow-up, mortality data were available on 12 patients; of these, 11 had died. The lone survivor was the patient without a parotid metastasis. Among those known to have died, survival ranged from 1.6 to 49.2 months (mean: 16.0). We conclude that parotid metastasis in patients with MCC of the head and neck is associated with a dismal survival rate that is even worse than the poor survival associated with cervical node involvement.
Merkel cell carcinoma of lymph node with unknown primary has a significantly lower association with Merkel cell polyomavirus than its cutaneous counterpart
