Skin melanocytic tumor
Topics to be merged
Giant congenital nevus
Author: Christopher S. Hale, M.D.
Topic Completed: 1 November 2012
Minor changes: 3 November 2020
Copyright: 2003-2021, PathologyOutlines.com, Inc.
PubMed Search: Giant congenital nevus
Table of Contents
Definition / general | Terminology | Epidemiology | Sites | Case reports | Treatment | Clinical images | Microscopic (histologic) description | Microscopic (histologic) images | Molecular / cytogenetics descriptionCite this page: Hale CS. Giant congenital nevus. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skintumormelanocyticgiantcongenitalnevus.html. Accessed March 5th, 2021.
Definition / general
- See: Congenital nevus
- Congenital melanocytic nevi diameter > 20 cm (J Cutan Pathol 2010;37:764)
Terminology
- Also called giant pigmented nevus or giant hairy nevus
Epidemiology
- 1 in 500,000 live births (Br J Dermatol 1981;104:307)
- ~2.5% risk of malignant transformation, usually before adolescence (Br J Dermatol 2006;155:1); may give rise to cutaneous or CNS melanoma or related neuroectodermal tumors (malignant peripheral nerve sheath tumor, cutaneous malignant melanotic neurocristic tumor, rhabdomyosarcoma, liposarcoma)
- May contain pseudotumoral proliferative nodules that ulcerate (J Cutan Pathol 2010;37:764)
- May have satellite nevi, including within mucosal membranes
- Truncal nevi may develop symptomatic neurocutaneous melanosis (meningeal or cerebral melanosis), lethal in 1/3 (J Am Acad Dermatol 2006;54:767)
Sites
- Dermatomal, "bathing suit" or "garment" configuration; may involve entire scalp, extremity, most of trunk or placenta
- Scalp lesions are often in thickened folds of skin resembling cerebrum, may involute in first 2 years of life (J Am Acad Dermatol 2008;58:508)
Case reports
- Newborn with neurocutaneous melanosis (J Neuroradiol 2007;34:272)
- Neonate with nevus sebaceus of scalp and limbal dermoid on left eye (J Am Acad Dermatol 2008;58:884)
- Neonate with extensive proliferative nodules (Clin Exp Dermatol 2008;33:125)
- Girl with ulcerated and sclerotic lesion (Clin Exp Dermatol 2007;32:529)
- Desmoplastic lesion with progressive depigmentation (J Am Acad Dermatol 2007;56:S10)
Treatment
- Possibly none for newborn scalp lesions
- Excision may require careful planning and several stages (Plast Reconstr Surg 2008;121:1674)
- Often split thickness skin grafting (Ann Plast Surg 2008;60:283)
- Laser surgery if inoperable (Clin Exp Dermatol 2007;32:159)
Clinical images
Images hosted on other servers:
Newborn with giant hairy congenital nevus
Ulcerated nodule within scalp
Microscopic (histologic) description
- Similar to congenital nevus
- Deeper nevus cells may be E-cadherin negative, contributing to their motility (J Dermatol Sci 2008;52:21)
Microscopic (histologic) images
Images hosted on other servers:
Proliferation of melanocytes along hair follicle
Melanocytes are uniform in large ulcerated nodule
Molecular / cytogenetics description
- May have proteomic alterations that predispose to tumorigenesis (Proteome Sci 2012;10:50)
