All the following are premalignant lesions except
High-Yield Explanation
Extramammary Paget's disease (intraepidermal adenocarcinoma)This occurs in cutaneous sites rich in apocrine glands such as the axillae, genital and perianal regions. Approximately 25% are associated with an underlying in situ or invasive adenocarcinoma.Giant congenital pigmented naevus (GCPN) or giant hairy naevusIt is a hamaoma of naevo - melanocytes that has a tendency to dermatomal distribution. It has a similar histology to compound naevi, but the naevus cells are distributed variably from the epidermis throughout all layers and into the subdermal fat and muscle. GCPNs are precursors of melanoma, a 3-5% lifetime risk of melanoma is quoted.Atypical (dysplastic) naevusTo be 'atypical naevi', lesions must have three of the following characteristics: variegated pigmentation; ill-defined borders; undulating irregular surfaces; or measure >5 mm. They can be sporadic or familial (familial atypical multiple mole melanoma (FAMMM) syndrome).Possession of more than five confers a relative risk of melanoma six times greater than usual; within FAMM syndrome, they confer a life-long 10% risk of MM.Ref: Bailey and Love, 27e, page: 603