pigmentation phenotype abnormal melanocyte morphology MP:0002877 MPheno.ontology Note that significant differences exist among populations of melanocytes that populate the cutaneous tissue compared to melanocytes that populate ocular, auditory, and internal body sites. Extracutaneous melanotcytes synthesize melanosomes and melanin only during a short interval after arriving in their target tissue, and they retain their melanosomes throughout the life of the organism instead of transferring to neighboring cells like dermal melanocytes. General morphology and ultrastructure of extracutaneous melanocytes vary and also differ from cutaneous melanocytes. abnormal melanocytes any structural anomaly of the cells that produce pigment