http://www.histopathology-india.MelanocyticTumours.htm

Ancient Naevus 
Halo naevus
Balloon cell naevus
Combined Naevus
Recurrent melanocytic naevus
                   
2. Spindle and epithelioid cell naevi

Spitz naevus
Pigmented spindle cell naevus

3. Blue naevi

Common blue naevus 
Cellular blue naevus

4. Dermal melanocytoses

Naevus of Ota
Naevus of Ito
Mongolian spot  

5. Congenital melanocytic naevi                                              
6. Dysplastic melanocytic naevi

Histopathology reveals  that the lesion may be junctional, compound  or intradermal  in type.
Naevus cells are present in the lower  two-third of the dermis. These cells extend around the nerves, blood vessels and adnexae. Involvement of eccrine glands and septa is an important feature of a true congenital naevus.  Naevus cells extend between collagen fibres singly or in a Indian file pattern.

Melanoma arising in small congenital naevi  has a less aggressive growth pattern. Melanoma arising in giant congenital naevi are usually  non epidermal in origin. The tumour cell patterns include spindle and round cell differentiation, malignant blue naevus  and heterologous differentiation (eg neurosarcoma, liposarcoma, rhabdomyosarcoma etc)
               DermAtlas-Links 1 ; 2 ;  3 ; 4

A retrospective cohort study of Southeast Asian patients with large congenital melanocytic nevi and the risk of melanoma development.J Am Acad Dermatol. 2006 May;54(5):778-82. Epub 2006 Mar 29.

Large or multiple congenital melanocytic nevi: occurrence of neurocutaneous melanocytosis in 1008 persons.J Am Acad Dermatol. 2006 May;54(5):767-77. Epub 2006 Feb 2

Proliferative nodules with balloon-cell change in a large congenital melanocytic nevus.J Cutan Pathol. 2006 Mar;33(3):253-5.

Congenital melanocytic nevi: clinical and histopathologic features, risk of melanoma, and clinical management.J Am Acad Dermatol. 2005 Feb;52(2):197-203.

Speckled lentiginous nevus: within the spectrum of congenital melanocytic nevi.Arch Dermatol. 2001 Feb;137(2):172-8.

Small congenital nevi associated with melanoma: case reports and considerations.J Dermatol. 2000 Sep;27(9):583-90.

Histologic features of congenital melanocytic nevi in infants 1 year of age or younger.J Am Acad Dermatol. 1995 Nov;33(5 Pt 1):780-5.

Histopathology of congenital pigmented nevi.Am J Dermatopathol. 1989 Feb;11(1):11-2.

The histology of "congenital features" in early acquired melanocytic nevi.J Am Acad Dermatol. 1988 Oct;19(4):742-6.

Immunohistologic patterns of congenital nevocellular nevi.Arch Dermatol. 1986 Nov;122(11):1263-8

Congenital smooth muscle hamartoma masquerading as congenital pigmented nevus.J Dermatol Surg Oncol. 1985 Jul;11(7):714-7.

Patterns of congenital nevocellular nevi. A histologic study of thirty-eight cases.J Am Acad Dermatol. 1983 Sep;9(3):388-93.
 

Prognostic parameters of melanoma

Lentigo maligna melanoma

Superficial spreading melanoma

Nodular melanoma

Acral lentiginous melanoma

Desmoplastic  melanoma

Naevoid melanoma

Balloon cell melanoma