Contributor: Gordon K. Klintworth
A spindle B melanoma is a specific morphologic type of uveal melanoma [melanoma - uvea]. Four distinct cell types are recognized in uveal melanomas: spindle A cells, spindle B cells, epithelioid cells, and intermediate cells. Depending on the predominant cell type uveal melanomas are classified into different types: spindle A melanoma [melanoma - spindle A], spindle B melanoma, epithelioid melanoma [melanoma - epithelioid], intermediate cell melanoma [melanoma - intermediate cell], and mixed cell melanoma [melanoma - mixed cell]. Spindle B melanomas are composed of spindle B cells. Spindle B melanomas have a better prognosis than epithelioid melanomas, but it is not as good as with spindle A melanoma.