A network pattern in benign lesions consists of uniform light to dark brown pigmented lines and hypopigmented holes that thin at the periphery, while a network in malignant lesions is non-uniform in color, asymmetrically distributed, and often accentuated at the periphery. Benign lesions also have hyperpigmented structureless areas that are centrally located or extend almost to the periphery, whereas malignant lesions have asymmetrically located hyperpigmented structureless areas. Being able to recognize the appearances of different patterns is important for diagnosing melanocytic lesions.

2. Dotted vessels

5. So, knowing the appearances
of various patterns is an
important skill for diagnosing
melanocytic lesions.
Let us now focus on specific
structures.

6. Network
Benign Lesions Malignant Lesions
A network consists The network is non-
of uniform light to uniform in color, is
dark brown asymmetrically
pigmented lines and distributed and often
hypopigmented is accentuated at
holes, and the periphery.
thins at the
periphery.

7. Uniform Network Non-uniform Network

8. Uniform Network Non-Uniform Network

9. Uniform Network Non-Uniform Network

10. Dark, Structureless Area
Benign Lesions Malignant Lesions
For benign lesions, For melanomas,
the hyperpigmented hyperpigmented
structureless area is structureless areas
either centrally located are asymmetrically
or extends almost to located.
the periphery of the
lesion.