Sclerosing 'mucinous' blue naevus.

Abundant mucin deposition is an unusual finding in melanocytic naevi. We describe the first example, to our knowledge, of a sclerosing blue naevus with an abundant mucinous stroma in two unrelated patients. This uncommon variant of blue naevus should be differentiated from desmoplastic-neurotropic melanoma, in which the presence of mucin stromal deposition is a more typical finding.