Epidermal cyst L72.0

Solitary or multiple, located in the middle or deep dermis, harmless, epithelium-lined, variously sized, usually skin-colored, 1.0 - 3.0 cm, sharply circumscribed cysts, with gelatinous or solid contents, of different genesis (traumatic, inflammatory, genetic).

A distinction is made according to the shutter release:

• Primary epidermal cyst: Etiologically unexplained.
• Secondary epidermal cyst: Traumatically induced.

In most cases retentions resulting from obstruction of the follicleostium, which secondarily lead to proliferation of the follicular epithelium. Multiple epidermal cysts on the trunk usually occur in connection with an acne vulgaris or conglobata. The etiology of the so-called primary epidermal cysts is unclear.

Adolescents, young and middle-aged adults. Not infrequently also in advanced age in actinically damaged skin.

Ubiquitous; mainly affects face, trunk, proximal extremity and rarely soles of feet

Solitary or plural, indolent, deep dermal, well demarcated, 0.2 to 3.0-5.0 cm, skin-colored, only rarely pigmented, turgidly elastic tumor that is slidable on the base. Clinically and dermatoscopically, a central porus is usually demonstrable. Rupture and consecutive acute abscess formation(furuncle) are possible.

Multiple epidermal cysts often have a history of acne vulgaris or acne conglobata.

Multiple epidermal cysts may occur in association with actinic elastosis and comedones in Favre-Racouchaud's disease.

The smallest epidermal cysts are called milia and are primary or secondary (post-traumatic).

Multiple epidermal cysts are characterized by the so-called sebocystomatosis scroti and steatocystoma multiplex.

Multiple epitdermal cysts may be a partial symptom of Gardner's syndrome or basal cell nevus syndrome.

Multiple epidermal cysts have also been observed sporadically after immunosuppressive treatment of organ transplant patients with ciclosporin A.

The cyst wall consists of layered squamous epithelium with formation of a stratum granulosum. In the lumen there are stratified horny lamellae like onion shells and more or less hairs depending on the age of the cyst. In case of rupture, dense granulomatous infiltrate with giant cells of foreign body type is found in the cyst lumen and in the surrounding area.

Tricholemmal cyst

Hidrocystoma

Ganglion

Mucocele

1. Basterzi Y et al (2002) Giant epidermoid cyst on the forefoot. Dermatol Surg 28: 639-640
2. Cameron DS et al (2003) Squamous cell carcinoma in an epidermal inclusion cyst: case report. Otolaryngol Head Neck Surg 129: 141-143
3. El Alami M et al (2003) Laser marsupialization of epidermal cysts: avoiding linear scars. J Clin Laser Med Surg 21: 161-163
4. Ghigliotti G et al (2014) Usefulness of dermoscopy for the diagnosis of epidermal cyst: the 'pore' sign. Clin Exp Dermatol 39:649-650
5. Gupta S et al (2000) Multiple, large, polypoid infundibular (epidermoid) cysts in a cyclosporine-treated renal transplant recipient. Dermatology 201: 78
6. Ishida M et al (2014) Epidermal cyst of the skin with ossification: report of two cases. Int J Clin Exp Pathol 7:1823-1825
7. Lee S et al (2003) Detection of human papillomavirus 60 in epidermal cysts of nonpalmoplantar location. Am J Dermatopathol 25: 243-247
8. Morgan MB et al (2001) Carcinoma arising in epidermoid cyst: a case series and aetiological investigation of human papillomavirus. Br J Dermatol 145: 505-506
9. Shet T, Desai S (2001) Pigmented epidermal cysts. Am J Dermatopathol 23: 477-481
10. Tsuruta D et al (2000) Combined cutaneous hamartoma encompassing benign melanocytic naevus, vellus hair cyst and epidermoid cyst. Clin Exp Dermatol 25: 38-40