Dermoscopy of pigmented seborrheic keratosis: a morphological study

Arch Dermatol. 2002 Dec;138(12):1556-60. doi: 10.1001/archderm.138.12.1556.


Objectives: To describe morphological features of seborrheic keratosis as seen by dermoscopy and to investigate their prevalence.

Design: Prospective cohort study using macrophotography and dermoscopy for the documentation of seborrheic keratosis.

Settings: Seborrheic keratoses were prospectively collected in 2 sites: a private practice in Plantation, Fla (site 1), and the Department of Dermatology at the University Hospital Geneva in Switzerland (site 2).

Patients: A total of 203 pigmented seborrheic keratoses (from 192 patients) with complete documentation were collected (111 from site 1 and 93 from site 2).

Interventions: Screening for new morphological features of seborrheic keratosis and evaluation of all lesions for the prevalence of these criteria.

Main outcome measures: Identification of new morphological criteria and evaluation of frequency.

Results: A total of 15 morphological dermoscopic criteria were identified. Standard criteria such as milialike cysts and comedolike openings were found in a high number of cases (135 and 144, respectively). We found network and networklike structures to be present in 94 lesions (46%). Using standard diagnostic criteria for seborrheic keratosis, 30 lesions would not have been diagnosed as such.

Conclusions: The classic dermoscopic criteria for seborrheic keratosis (milialike cysts and comedolike openings) have a high prevalence but the use of additional dermoscopic criteria such as fissures, hairpin blood vessels, sharp demarcation, and moth-eaten borders improves the diagnostic accuracy. The proper identification of pigment network and networklike structures is important for the correct diagnosis.

MeSH terms

  • Biopsy, Needle
  • Cohort Studies
  • Dermatology / methods*
  • Diagnosis, Differential
  • Female
  • Humans
  • Incidence
  • Keratosis, Seborrheic / diagnosis*
  • Keratosis, Seborrheic / pathology
  • Male
  • Melanoma / diagnosis*
  • Melanoma / pathology
  • Prognosis
  • Prospective Studies
  • Risk Assessment
  • Severity of Illness Index
  • Skin Neoplasms / diagnosis*
  • Skin Neoplasms / pathology