Melanocytic nevus

Melanocytic nevus 

Updated: 07/01/2023

© Jun Wang, MD, PhD

General features
  • Congenital or acquired
  • Benign nested melanocytic proliferation
  • Most common melanocytic tumor
  • May recur with incomplete excision
  • Recurrent nevus ("persistent nevus") may resemble melanoma  
  • Risk factors
    • Sun exposure
    • Light skin
    • Family history
Clinical features
  • Macule (junctional) or papule/nodule (intradermal/compound)
  • Hyperpigmentation
  • Regular pigmentation, shape and border
Pathological features
  • Nests of melanocytes
  • Melanocytes decrease in size towards base of lesion
  • Classified according to location
Junctional: Nest at dermal epidermal junction
Intradermal: Nest within dermis
Compound: Both junctional and dermal components
  • Other types of melanocytic nevus
Molecular abnormalities
  • Acquired RAS/BRAF mutations
Marker
  • Positive: S100
  • Negative: cytokeratin
Dysplastic nevus
Management
  • Follow up
  • Removal


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Pathology notes Jun Wang, MD, PhD 1. General information Frequently discussed syndromes Terms of dermatology Terms of hematology 2. Primary immunodeficiency disorders 3. Hemodynamic abnormalities Shock Thrombosis and embolism Bleeding disorders 4.  Benign blood cell disorders Anemia Benign white cell disorders 5. Hematopoietic neoplasms Lymphoid neoplasms Myeloid neoplasms Histiocytic neoplasms: Langerhans cell histiocytosis 6. Cardiovascular system Pulmonary hypertension Cardiovascular system tumors 7. Respiratory tract tumors 8. Gastrointestinal tract Congenital disorders Infectious gastroenteritis Oral cavity Esophagus Stomach Intestinal tumors Salivary glands Exocrine pancreas and gallbladder 9. Urinary system Kidney masses Lower urinary tract 10. Male reproductive system 11. Female genital tract 12. Breast 13. Endocrine organs Pituitary gland Adrenal gland Thyroid gland Parathyroid gland Endocrine pancreas...
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