Amelanotic Melanoma Concealed by Psoriasis.

Amelanotic melanoma (AM) is a rare subtype of cutaneous melanoma that lacks melanin pigment. Clinical diagnosis of AM is challenging because it may mimic benign or malignant melanocytic and non-melanocytic neoplasms and inflammatory skin diseases. Completely amelanotic melanomas are rare, but approximately 2-8% of all melanomas lack pigment or are sparsely pigmented (1, 2). AM often present a particular diagnostic challenge due to their inconspicuous appearance and lack of the classical, well-recognized characteristics and clues found in pigmented lesions (3). In particular, when concealed by an inflammatory dermatosis, such as psoriasis, AM can remain undiagnosed for a long time (4). We describe here, to our knowledge, the first case of AM concealed by psoriasis.