Cutaneous Melanoacanthoma Clinical Presentation

Updated: Apr 05, 2021
  • Author: Robert A Schwartz, MD, MPH; Chief Editor: Dirk M Elston, MD  more...
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Cutaneous melanoacanthomas are painless and slow growing. The slow but persistent growth and related cosmetic problems with melanoacanthomas may prompt an affected individual to consult a physician.

Patients are generally asymptomatic; however, trauma or manipulation of the melanoacanthoma may lead to bleeding or inflammation. Patients may live with cutaneous melanoacanthoma for decades before they seek treatment.

Oral melanoacanthoma is rare, first noted with the sudden appearance and rapid growth of a brown-black macule. [18] Gingival melanoacanthomas may be evident as solitary or multiple. [19] Oral melanoacanthoma may be bilateral. [20] It may rarely appear on the gingiva. [21]


Physical Examination

Melanoacanthomas are most often solitary. Multiple melanoacanthomas have been described. In one case, a 40-year-old man had multiple, minute, discrete or confluent shiny papules limited to his left upper eyelid. [22] They may rarely appear as multiple, asymptomatic, slowly growing, raised pigmented nodules and tumors scattered all over the body. [23] An ulcerating tumor has been described in one of the lesions.

Cutaneous melanoacanthomas are found mainly on the trunk or head, often on the lip or eyelid. They have also been observed on the penile shaft [16] and in the genital regions as a large, solitary, slowly enlarging, hyperpigmented verrucous tumor with a cerebriform surface. [24]

Cutaneous melanoacanthomas may be hyperpigmented or verrucous and round or oval. The lesion may be a papule, plaque, cutaneous horn, or nodule. Lesional diameters range from a few millimeters to 10 cm. Note the image below.

Large cutaneous melanoacanthoma in a 45-year-old m Large cutaneous melanoacanthoma in a 45-year-old man that obstructs his vision.

The authors have observed a darkly pigmented cutaneous horn that extended from the left upper eyelid to below the lower eyelid in a 45-year-old man; the lesion had histologic findings consistent with melanoacanthoma (see image below).

Melanoacanthomas can occur on the oral mucosa, [25] but oral lesions are distinct from cutaneous melanoacanthomas. [9, 26]  Dermatoscopic features have been described. [27]



Melanoacanthomas that extend from the upper eyelid to beyond the lower eyelid can obstruct the patient's vision.