Cutaneous malignancy in arsenicosis.

Sir, Arsenicosis or chronic arsenic toxicity due to consuming groundwater containing arsenic above the safe limit of 0·05 mg L−1, as laid down by the World Health Organization,1 was discovered by the author in 19822 in patients from West Bengal, India, and in 1984 in a patient from Bangladesh.3 Cancer from medicinal arsenic used in the treatment of psoriasis was first detected by Hutchinson4 in 1887. Among 20 places in different countries where a high concentration of groundwater arsenic was found, West Bengal and Bangladesh are suffering from the biggest arsenical calamity in the world.5 A previous study reported clinical features of 4865 patients with arsenical dermatosis from 1206 villages of nine districts in West Bengal during the period 1983–87.6 The present study addresses neoplasia developing during 1983–99 in the same subjects. In this group, 250 subjects (5·1%) developed a malignancy: 212 had skin cancers (84·8%) and the remaining 38 had internal cancers (15·2%). Skin cancers comprised 161 cases of squamous cell carcinoma and 51 cases of Bowen's disease or intraepidermal carcinoma. The cancers were mostly monocentric but one patient had 26 separate skin cancers. No basal cell carcinomas or malignant melanomas were seen in this series of cases. Among the 38 cases of internal cancers, lung carcinoma was most common (25 cases), followed by bladder and genital tract carcinoma (five cases each); only three cases of gastric cancer were found.