Seborrheic keratosis
| Seborrheic keratosis | |
|---|---|
| Specialty | Dermatology  |
A seborrheic keratosis, also known as seborrheic verruca, basal cell papilloma, or a senile wart,[1][2]: 767 [3]: 637 is a non-cancerous (benign) skin tumour that originates from cells in the outer layer of the skin (keratinocytes). Like liver spots, seborrheic keratoses are seen more often as people age.[4]
The tumours (also called lesions) appear in various colours, from light tan to black. They are round or oval, feel flat or slightly elevated, like the scab from a healing wound, and range in size from very small to more than 2.5 centimetres (1 in) across.[5] They can often come in association with other skin conditions, including basal cell carcinoma.[6] Sometimes seborrheic keratosis and basal cell carcinoma occur at the same location, and sometimes seborrheic keratosis progresses to basal cell carcinoma. At clinical examination the differential diagnosis include warts[4] and melanoma. Because only the top layers of the epidermis are involved, seborrheic keratoses are often described as having a "pasted on" appearance. Some dermatologists refer to seborrheic keratoses as "seborrheic warts", because they resemble warts, but strictly speaking the term "warts" refers to lesions that are caused by human papillomavirus.[7]
Classification
Seborrheic keratoses may be divided into the following types:[2]: 769–770
- Common seborrheic keratosis (basal cell papilloma, solid seborrheic keratosis)
- Reticulated seborrheic keratosis (adenoid seborrheic keratosis)
- Stucco keratosis (digitate seborrheic keratosis, hyperkeratotic seborrheic keratosis, serrated seborrheic keratosis, verrucous seborrheic keratosis) -- Often are light brown to off-white. Pinpoint to a few millimeters in size. Often found on the distal tibia, ankle, and foot.[8]
- Clonal seborrheic keratosis
- Irritated seborrheic keratosis (inflamed seborrheic keratosis)
- Seborrheic keratosis with squamous atypia
- Melanoacanthoma (pigmented seborrheic keratosis)
- Dermatosis papulosa nigra—Commonly found among adult dark-skinned individuals, presents on the face as small benign papules from a pinpoint to a few millimeters in size.[9]
- Inverted follicular keratosis[10]
Cause
The cause of seborrheic keratosis is not known.[4]
Diagnosis
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Visual diagnosis is made by the "stuck on" appearance, horny pearls or cysts embedded in the structure. Darkly pigmented lesions can be challenging to distinguish from nodular melanomas.[11] Furthermore, thin seborrheic keratoses on facial skin can be very difficult to differentiate from lentigo maligna even with dermatoscopy. Clinically, epidermal nevi are similar to seborrheic keratoses in appearance. Epidermal nevi are usually present at or near birth. Condylomas and warts can clinically resemble seborrheic keratoses, and dermatoscopy can be helpful. On the penis and genital skin, condylomas and seborrheic keratoses can be difficult to differentiate, even on biopsy.
A study examining over 4000 biopsied skin lesions showed identified as seborrheic keratoses showed 3.1% were malignancies. Two-thirds of those were squamous cell carcinoma.[12]
To date, the gold standard in the diagnosis of seborrheic keratosis is represented by the histolopathologic analysis of a skin biopsy.
Treatment
No treatment of seborrheic keratoses is necessary, except for aesthetic reasons.[4] Since a slightly increased risk of localized infection caused by picking at the lesion has been described, if a lesion becomes itchy or irritated by clothing or jewelry, a surgical excision is generally recommended.
Small lesions can be treated with light electrocautery. Larger lesions can be treated with electrodesiccation and curettage, shave excision, or cryosurgery. When correctly performed, removal of seborrheic keratoses will not cause much visible scarring except in persons with dark skin tones.
Epidemiology
Seborrheic keratosis is the most common benign skin tumor. Incidence increases with age. There is less prevalence in people with darker skin.[13] In large-cohort studies, 100% of the patients over age 50 had at least one seborrheic keratosis.[14] Onset is usually in middle age, although they are common in younger patients too—found in 12% of 15-year-olds to 25-year-olds—making the term "senile keratosis" a misnomer.[15]
See also
References
- ^ Hafner, C; Vogt, T (Aug 2008). "Seborrheic keratosis". Journal der Deutschen Dermatologischen Gesellschaft. 6 (8): 664–77. doi:10.1111/j.1610-0387.2008.06788.x. PMID 18801147.
- ^ a b Freedberg, et al. (2003). Fitzpatrick's Dermatology in General Medicine. (6th ed.). McGraw-Hill. ISBN 0-07-138076-0.
- ^ James, William D.; Berger, Timothy G.; et al. (2006). Andrews' Diseases of the Skin: Clinical Dermatology. Saunders Elsevier. ISBN 0-7216-2921-0.
- ^ a b c d Moles, Freckles, Skin Tags, Benign Lentigines, and Seborrheic Keratoses from the Cleveland Clinic website
- ^ Seborrheic keratosis: Symptoms, from the Mayo Clinic website
- ^ Fusco, N.; Lopez, G.; Gianelli, U. (2015). "Basal Cell Carcinoma and Seborrheic Keratosis: When Opposites Attract". International Journal of Surgical Pathology. 23 (6): 464. doi:10.1177/1066896915593802. PMID 26135529.
- ^ Reutter, Jason C.; Geisinger, Kim R.; Laudadio, Jennifer (2014). "Vulvar Seborrheic Keratosis". Journal of Lower Genital Tract Disease. 18 (2): 190–4. doi:10.1097/LGT.0b013e3182952357. PMID 24556611.
- ^ Stucco Keratosis at eMedicine
- ^ Dermatosis Papulosa Nigra at eMedicine
- ^ Busam, Klaus J. (2010). Dermatopathology. Saunders. p. 341. ISBN 978-0-443-06654-2.
- ^ http://ssai-starss.com/seborrheic-keratosis-scalp-etiology-treatment
- ^ Chen, Tiffany Y.; Morrison, Annie O.; Cockerell, Clay J. (2017-09-01). "Cutaneous malignancies simulating seborrheic keratoses: An underappreciated phenomenon?". Journal of Cutaneous Pathology. 44 (9): 747–748. doi:10.1111/cup.12975. ISSN 1600-0560.
- ^ Zhang, Ru-Zhi; Zhu, Wen-Yuan (2011). "Seborrheic keratoses in five elderly patients: An appearance of raindrops and streams". Indian Journal of Dermatology. 56 (4): 432–434. doi:10.4103/0019-5154.84754. PMC 3179013. PMID 21965858.
{{cite journal}}: CS1 maint: unflagged free DOI (link) - ^ Yeatman JM, Kilkenny M, Marks R (Sep 1997). "The prevalence of seborrhoeic keratoses in an Australian population: does exposure to sunlight play a part in their frequency?". Br J Dermatol. 137 (3): 411–4. doi:10.1111/j.1365-2133.1997.tb03748.x.
- ^ Gill D, Dorevitch A, Marks R (Jun 2000). "The prevalence of seborrheic keratoses in people aged 15 to 30 years: is the term senile keratosis redundant?". Arch Dermatol. 136 (6): 759–62. doi:10.1001/archderm.136.6.759.
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