[Metastasis to the parotid gland]

The skin areas that primarily drain into the parotid lymph nodes include large parts of the face, cheek, anterior surface of the auricle, temporal region, scalp and forehead. Malignant tumours, mainly squamous cell carcinomas and malignant melanomas, may therefore metastasis to the parotid gland. It may, however, sometimes be difficult to decide whether the parotid tumour is a primary or secondary tumour.

Twenty-six patients treated for metastatic malignant disease to the parotid gland were evaluated retrospectively. The mean age of the 22 males and four female patients was 70 years.

In nine patients (35%), the primary tumour was ignored and wrongly interpreted as a tumour originating in the parotid gland. The primary tumour was localised in the temple in six patients, in the cheek in six, in the anterior surface of the outer ear in five, in the eyelids in four, in the forehead in one, in the scalp in one, and in the nasal vestibulum or nasal cavity in three patients. 19 patients (73%) had squamous cell carcinomas and seven (27%) malignant melanomas. The treatment was surgery supplied by radiotherapy in 19 patients. Four (21%) of the patients with squamous cell carcinoma and four (57%) of those with malignant melanoma died from the disease.

When a tumour arises in the parotid gland, the physician should critically evaluate whether this represents a secondary tumour. Careful examination of the scalp and face for suspect skin lesions and scars from extirpation of previous skin cancer can help detect the primary tumour.