Seborrhoeic keratosis or occult malignant neoplasm of the skin?

Seborrhoeic keratosis is generally considered to be a benign lesion of the skin.

We present the case of a 68-year-old male who presented with clinically typical seborrhoeic keratosis that later histological examination showed partially covered an occult basal cell carcinoma.

To have an indication of what percentage of clinically apparent seborrhoeic keratoses may be associated with some form of histologically proven skin malignancy.

We carried out a retrospective analysis of approximately 23,000 histopathological examinations done on specimens from dermatological lesions.

Fifty-nine (11.9%) clinically apparent seborrhoeic keratoses were later histologically diagnosed as basal cell carcinomas, 17 (3.4%) as squamous cell carcinomas, and five (1.01%) as malignant melanomas.

Although the association of seborrhoeic keratosis and skin malignancy appears to be relatively uncommon, the possibility of such an association cannot be ruled out.