Abstract
Pigmentary mosaicism refers to patterned hypo- and/or hyperpigmentation that results
from genetic heterogeneity of skin cells. The most common clinical patterns are streaks
and swirls following Blaschko's lines in narrow or broad bands and a block-like distribution.
This contribution provides an update on the diverse genetic etiologies, cutaneous
findings, potential associated extracutaneous abnormalities, and management of various
forms of pigmentary mosaicism. Current terminology, the recent reappraisal of the
classic patterns based on scientific advances, and distinct clinicogenetic entities
are highlighted. A practical approach to the diagnosis and evaluation of patients
with pigmentary mosaicism is provided, including clues to distinguish other conditions
in the differential diagnosis and applications of advances in genetic testing technology.
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Published online: March 11, 2022
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