Malignant melanomas of the parotid: comparison of survival for patients with metastases from known vs unknown primary tumor sites.
BACKGROUND
Malignant melanoma (MM) rarely affects the parotid, and usually this diagnosis will herald a search for a primary skin neoplasm. Occasionally, no primary tumor is ever found, raising questions regarding prognosis and the issue of primary melanoma of the parotid.


OBJECTIVE
To evaluate retrospectively the clinical and histological features of MM involving the parotid in 19 patients.


METHODS
Pathology and hospital files at 3 tertiary care university hospitals.


METHODS
Patients with MM within the parotid with adequate histopathologic and immunohistochemical documentation, as well as clinical information regarding patient outcome.


METHODS
In 6 patients, no extraparotid MM was ever identified. After parotidectomy, 5 patients (including 1 patient who died of other causes) were melanoma free at a mean of 4.2 years (range, 14 months to 7.5 years). Only 1 patient died of disease after 17 months. An extraparotid primary tumor was present in 13 patients, 10 with dermal and 3 with mucosal sites. At follow-up, only 1 of these patients was disease free after 2 years. Nine patients died of melanoma after a mean of 2.6 years (range, 10 months to 5 years); the other 3 had evidence of metastatic disease at a mean of 4.3 years (range, 3-6 years). Nondermal sites of primary tumors were the nasal cavity, sclera, and conjunctiva.


RESULTS
Patients with metastatic MM from unknown primary tumors have a longer disease-free survival than those with metastases from known primary disease.


CONCLUSIONS
Although rare, MM should be considered in the differential diagnosis of parotid tumors. Unusual mucosal or ocular sites should be considered in the search for possible primary tumor sites to avoid treatment delay. These data support the idea that patients with metastatic MM from unknown primary tumors may follow a more improved course than that of patients with metastases from known primary disease.
Wang
B Y
BY
Lillian and Henry M. Stratton-Hans Popper Department of Pathology, Mount Sinai Medical Center, New York, NY 10029, USA.
Lawson
W
W
Robinson
R A
RA
Perez-Ordonez
B
B
Brandwein
M
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000401:mortality* / Q000473:pathology / Q000556:secondary* / Q000601:surgery; D008875:Middle Aged; D009382:Neoplasms, Unknown Primary / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D010306:Parotid Gland / Q000473:pathology / Q000601:surgery; D010307:Parotid Neoplasms / Q000401:mortality* / Q000473:pathology / Q000556:secondary* / Q000601:surgery; D012189:Retrospective Studies; D013997:Time Factors