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Common benign skin lesions

Author: Wafaa Binti Mowlabaccus, Medical Student, Department of Medicine, University of Mauritius, Reduit, Moka, Mauritius. DermNet NZ Editor in Chief: Adjunct A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand. Copy edited by Gus Mitchell. July 2020.


What is a benign skin lesion?

A benign skin lesion is a non-cancerous skin growth.

Who gets benign skin lesions?

Any individual from any age group can present with a benign skin lesion.

What are the features of benign skin lesions?

The features in common for benign skin lesions include:

  • Symmetry in shape, colour and structure
  • Stable or slowly evolving
  • Absence of spontaneous bleeding (bleeding or ulceration may be due to recent injury).

Benign lesions can be classified by their cellular origin: melanocytic, keratinocytic, vascular, fibrous, fat, and so on,

Which are the common melanocytic lesions?

Common benign skin lesions of melanocytic origin include the ephilis, lentigo simplex, and melanocytic naevus (mole).

Ephilides are genetically determined well-defined small brown macules with the following characteristics:

  • 1–4 mm in diameter
  • Tan or brown colour
  • Located in areas exposed to the sun such as the face and forearms.
  • Increased melanin deposition in the basal keratinocyte on biopsy [1,2].

Lentigo simplex is not sun-induced. It has the following characteristics:

  • Well-circumscribed, uniform brown to black macule
  • Located on mucous membrane or skin, including palms and soles
  • Develops during childhood or young adult life [1,2].

A melanocytic naevus can be histologically classified as a junctional, compound, or dermal naevus depending on the location of nests of naevus cells.

A junctional naevus has naevus cells at the base of the epidermis.

  • A junctional naevus is well-circumscribed pigmented macule with regular but fading borders.
  • The number and appearance of junctional naevi depend on sun exposure, fluctuating hormonal levels, and immunosuppression [1,3].

Flat melanocytic lesions

A compound naevus has papular and flat components due to junctional and dermal naevus cells.

  • The compound naevus is usually a pink or brown, dome-shaped papule surrounded by macular pigmentation [3].
  • Most lesions arise during childhood.

A dermal naevus is characterised by naevus cells in the dermis.

  • The dermal naevus is an elevated papule.
  • It can be brown, blue, black or skin coloured.
  • Dermal naevi arise in childhood but mature during early adult life.

Elevated moles

Which are the common keratinocytic lesions?

Benign keratoses include solar lentigo and seborrhoeic keratosis.

A solar lentigo is a sun-induced pigmented macule.

  • Solar lentigines vary from small to large size and are usually tan to brown-black.
  • The lesions are mostly uniformly pigmented with a sharp border.
  • They arise in adult life and are prevalent in older people [1,2].

Solar lentigo

Seborrhoeic keratosis presents as a variable warty plaque.

  • Seborrhoeic keratosis has a dull, verrucous, or waxy surface with a classical stuck-on appearance.
  • The shape and structure are often irregular and varies over time.
  • They can be yellow to brown to black in colour or made up of several colours.
  • Skin biopsy reveals a papillomatous epidermis with a thick basal layer and presence of keratin-filled cysts [1,4].

Seborrhoeic keratosis

Epidermoid cyst is a follicular nodule with a central punctum.

  • This type of cyst can be skin-coloured to off-white and is a dome-shaped papule or nodule
  • Cheesy or yellowish keratin can be expressed through the punctum or removed by incising the cyst.
  • The epidermal cyst is lined with flat epidermal cells and has a granular layer surrounding laminated keratin [1,2].

Epidermoid cyst

Corns and calluses are localised areas of thickened skin induced by pressure

  • A corn (small tender papule) or callus (thickened non-tender plaque) is most often located on a pressure area of the hand or foot.
  • A soft corn is a scaly plaque while hard corn is a firm papule with a translucent central core [1,2].

Corns and calluses

Sebaceous hyperplasia occurs on the forehead and cheeks of adults.

  • It presents as one or more dome-shaped papules with central umbilication.
  • Uniform yellow lobules are seen on dermoscopy [1,2].

Sebaceous hyperplasia

Which are the common lesions of vascular origin?

An angioma is due to the proliferation of the endothelial cells.

  • A superficial angioma is a bright red colour and a deeper angioma is purple or blue.
  • Angiomas are commonly nodular or macular lesions of varying sizes.

Angioma

A pyogenic granuloma is a vascular response to trauma and bacterial infection.

  • It presents as a rapidly growing friable nodule on fingers, toes, or facial sites.
  • They have a yellow to violaceous colour.
  • The pyogenic granuloma is surrounded by a scaly collarette.

Pyogenic granuloma

Which are the common fibrous lesions?

Dermatofibroma is a reactive lesion that presents as one or more firm dermal papules.

  • The dermatofibroma is pink, tan or brown.
  • It forms a dimple when pinched.
  • A skin biopsy shows fibrohistiocytic cell proliferation with entrapment of collagen at the periphery [1,2].

Dermatofibroma

Which are the common subcutaneous lesions?

The lipoma is the most common benign soft-tissue tumour.

  • A lipoma presents as a soft, rubbery, freely mobile mass that is usually found on the back, neck, or trunk.
  • Skin biopsy shows white adipose tissue in the subcutaneous layer [1,2].

Lipoma

What is a skin tag?

The most common type of skin tag is also called acrochordon.

  • An acrochordon is a soft, fleshy papule that is almost always pedunculated.
  • They vary in diameter from 1 to 6 mm.
  • On biopsy, there is a fibrovascular core covered by normal squamous epithelium [2].

Skin tags

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Related information

 

References

  1. Higgins JC, Maher MH, Douglas MS. Diagnosing Common Benign Skin Tumors. Am Fam Physician 2015; 92: 601–7. PubMed
  2. Khandpur S, Ramam M. Skin tumours. J Cutan Aesthet Surg 2012; 5: 159–62. DOI: 10.4103/0974-2077.101368. PubMed Central
  3. Wollina U. Seborrheic Keratoses – The most common benign skin tumor of humans. Clinical presentation and an update on pathogenesis and treatment options. Open Access Maced J Med Sci 2018; 6: 2270–5. DOI: 10.3889/oamjms.2018.460. PubMed Central
  4. Common Benign Skin Tumors. Am Fam Physician 2003; 67: 729–38. PubMed

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