Malignant melanomas of the nasal cavity after occupational exposure to formaldehyde.

Formaldehyde is a well known nasal carcinogen in rodents, but so far there has been no convincing evidence that workers occupationally exposed to formaldehyde have an increased risk of nasal cancer. In this study three cases of malignant melanoma of the nasal mucosa in persons occupationally exposed to formaldehyde for a long time are presented. The occurrence of such a rare tumour in patients with significant exposure to a known carcinogen warrants further investigation.