Table of Contents
Spitz nevus – low magnification
LEGEND
Hyperkeratosis, frequent hypergranulosis
Symmetrical well-demarcated lesion that can be junctional, dermal, or compound
- Epidermal hyperplasia; epidermal ridges “grasp” the nests
- Sparse lymphocytic infiltrate
Spitz nevus
LEGEND
Normal maturation
Variable melanin
Pagetoid ascent or atypical cells may sometimes be observed in the upper portion and center of the lesion
- Vertically oriented nests composed of large spindle-shaped and/or epithelioid melanocytes
- Frequent presence of retraction artifact around the nests
Spitz nevus – high magnification
LEGEND
The nests are composed of large spindle-shaped and/or epithelioid melanocytes with abundant cytoplasm and prominent nucleolus
Spitz nevus – high magnification
LEGEND
Presence of Kamino bodies at the dermoepidermal junction. These correspond to eosinophilic aggregates of basement membrane material
Spitz nevus – low magnification
LEGEND
Pigment incontinence and melanophages in the dermis
Vertically oriented nests composed of large spindle-shaped and/or epithelioid melanocytes
Frequent presence of retraction artifact around the nests
Spitz nevus – high magnification
LEGEND
Frequent presence of retraction artifact around the nests
Normal maturation (i.e., the cells become progressively smaller with depth or remain the same size and lose their pigment-producing capacity)
Spitz nevus
Immunohistochemistry for Melan-A is positive; it is a marker of melanocyte differentiation
Spitz nevus
Loss of p16 expression can be evaluated, which is a marker of poor prognosis (seen in spitzoid melanomas)
In this case, p16 is expressed. This is a reassuring finding.
Spitz nevus – low magnification
LEGEND
Symmetrical, well-demarcated lesion, mostly junctional in this case, with vertically oriented and equidistant nests
- Frequent hyperkeratosis and hypergranulosis
- Epidermal hyperplasia; epidermal ridges “grasp” the nests
- Sparse underlying perivascular lymphocytic infiltrate
Spitz nevus – high magnification
LEGEND
Vertically oriented nests composed of large spindle-shaped and/or epithelioid melanocytes with abundant cytoplasm and a prominent nucleolus
- Frequent presence of retraction artifact around the nests
