pigmented basal cell carcinoma
Wednesday 22 May 2013
Melanin pigment is usually formed in solid, micronodular, multifocal superficial or follicular variants.
Functional melanocytes are scattered through the tumor islands and there are numerous melanophages in the stroma. There are few melanosomes within the tumor cells.
Melanosome complexes form in tumor cells as a consequence of repeated cycles of phagocytosis of melanosome‑containing tumor cells that have undergone apoptosis.
Basal cell carcinomas of the usual type are also populated by some melanocytes.
Other pigmented phenomena in basal cell carcinomas are the colonization one by a melanoma in situ, the metastasis of a melanoma to one, and the presence of a combined melanoma and basal cell carcinoma.