A 73-year-old woman was evaluated for a pigmented lesion on her face, and a biopsy revealed a seborrheic keratosis. A year later she was noted to have a painful rock hard brown plaque, which on epeat biopsy showed a desmoplastic melanoma overlying a lentigo maligna. Immunohistochemical analysis for S-100 was positive. Desmoplastic melanoma is a term first used by Conley in 1971 to describe a variant of melanoma characterized by a dermal spindle cell population in a background of abundant collagen. Eight years later, Reed and Leonard used the term desmoplastic neurotropic melanoma to describe desmoplastic melanomas with nerve infiltration. Although desmoplastic melanoma may arise de novo, it is most commonly associated with other types of melanoma, mainly lentigo maligna. Like lentigo maligna, desmoplastic melanoma occurs in older individuals, most commonly in the sixth decade of life, and has a slight predilection for males (male-to-female ratio 1.75:1). Lesions are most often located on sun-exposed skin of the head and neck but can also be located on the trunk or extremities.
Clinically, desmoplastic melanoma poses great diagnostic difficulty. Lesions are often described as raised, indurated nodules that are most often amelanotic. Although desmoplastic melanomas are typically diagnosed as advanced lesions, when matched stage for stage, they are generally considered to have survival rates similar to conventional melanomas.
large indurated red plaque involving much of he right cheek and lower eye lid with scattered overlying well demarcated 2 mm to 2 cm macules and patches