ABSTRACT
Pigmented squamous cell carcinoma is a very rare malignant, pigmented, epidermal tumor. The rarity of pigmented squamous cell carcinomas may reflect in part their misdiagnosis as other pigmented neoplasms, particularly malignant melanoma. To our knowledge, only five cases have been reported in literature. We recently experienced a case of pigmented squamous cell carcinoma arising from pigmented actinic keratosis in a 77 years old female. Physical examination showed a 0.8 0.6 cm, smooth, dark brown pigmented patch with irregular but sharply defined borders located on the upper left chest. The biopsy specimen showed histologic findings of pigmented actinic keratosis with abundant melanin pigments, which became pigmented squamous cell carcinoma. Most of pigments in the squamous cell carcinoma were contained within the melanocytes along with the neoplastic squamous cells.
Subject(s)
Aged , Female , Humans , Actins , Biopsy , Carcinoma, Squamous Cell , Diagnostic Errors , Keratosis, Actinic , Melanins , Melanocytes , Melanoma , Physical Examination , Skin , ThoraxABSTRACT
An 84-year-old woman had an ovoid shallow ulcer with an elevated, indurated, pigmented border on the left cheek. Histological examination revealed a moderately differentiated squamous cell carcinoma and a solar keratosis with abundant melanocytes and melanin pigment. Ultrastructurally, the keratinocytes contained numerous melanosomes in their cytoplasms and the melanocytes in the squamous cell carcinoma and the solar keratosis had mature melanosomes.