BACKGROUND: The association between the eruption of numerous seborrhoeic keratoses as a result of an underlying malignancy is controversially discussed. The aim of this case-control study with prospective accrual of patients was to determine whether a direct association exists between the number seborrhoeic keratoses and internal malignancies. METHODS: The numbers and sites of seborrhoeic keratoses were counted in 150 oncological patients and 150 matched controls. Additionally, the presence or absence of pruritus, acanthosis nigricans, and the sudden appearance of seborrhoeic keratoses were assessed. RESULTS: Seborrhoeic keratoses did not differ significantly between patients with internal malignancies and controls. Only two patients fulfilled the criteria of the Leser-Trélat sign, defined as the eruption of numerous seborrhoeic keratoses as a cutaneous marker of an underlying internal malignancy. CONCLUSION: No association was found between seborrhoeic keratoses and cancer. Furthermore, our data did not provide support to the validity of the Leser-Trélat sign in patients with internal malignancies.
BACKGROUND: The association between the eruption of numerous seborrhoeic keratoses as a result of an underlying malignancy is controversially discussed. The aim of this case-control study with prospective accrual of patients was to determine whether a direct association exists between the number seborrhoeic keratoses and internal malignancies. METHODS: The numbers and sites of seborrhoeic keratoses were counted in 150 oncological patients and 150 matched controls. Additionally, the presence or absence of pruritus, acanthosis nigricans, and the sudden appearance of seborrhoeic keratoses were assessed. RESULTS:Seborrhoeic keratoses did not differ significantly between patients with internal malignancies and controls. Only two patients fulfilled the criteria of the Leser-Trélat sign, defined as the eruption of numerous seborrhoeic keratoses as a cutaneous marker of an underlying internal malignancy. CONCLUSION: No association was found between seborrhoeic keratoses and cancer. Furthermore, our data did not provide support to the validity of the Leser-Trélat sign in patients with internal malignancies.