Lentigo Simplex (and related lesions)
Epidemiology and Etiology:
- Childhood most frequently
- Any age
- May be a precursor to junctional nevus
- Multiple lentigines
syndrome (LEOPARD syndrome):
- NAME or LAMB or myxoma
syndrome:
- Carney complex (syndromic):
- Peutz-Jeghers
syndrome:
Common sites:
- No predilection for areas of sun exposure
Gross features:
- Clinically indistinguishable from junctional nevus
- A few scattered lesions usually
- macules
- Small
- Symmetric
- Well-circumscribed
- Evenly pigmented, brown or black
- Not indurated
- Lentiginosis
profusa:
- Innumerable small, pigmented macules either
from birth or startging in childhood or early
adulthood
- Sparing mucous surfaces
- Multiple lentigines
syndrome (LEOPARD syndrome):
- Thousands of flat, dark-brown macules on the
skin but not on mucous surfaces
- syndromeic
- Speckled lentiginous nevus:
Histologic features:
- Slight or moderate elongation of rete ridges
- Increase in concentration of melanocytes in the
basal layer
- Focal contiguity with one another near the tips
and sides of the elongated rete
- Not continuous between the rete
- No nests by definition (lentiginous junctional
nevus / jentigo)
- Increase in amount of melanin in both
melanocytes and basal keratinocytes
- May be seen in upper layers including stratum corneum
- Melanophages
in the upper dermis
- Lentiginosis
profusa:
- Multiple lentigines
syndrome (LEOPARD syndrome):
- Speckled lentiginous nevus:
-
Immunophenotype:
Marker:
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Sensitivity:
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Specificity:
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Molecular features:
Other features:
References:
- Elder DE (ed.)
Lever’s Histopathology of the Skin, 10th ed (2009)