Reports
Amelanotic melanoma: The great masquerader

https://doi.org/10.1067/mjd.2000.103981Get rights and content

Abstract

Background: Cutaneous melanoma is often recognized by its dark color, but some tumors have little or no pigmentation. Objective: We present the clinical findings of 4 cases of primary cutaneous amelanotic melanoma in which the clinical diagnosis was unsuspected and one case of amelanotic metastatic melanoma. Methods: Five cases of melanoma are reviewed. The clinical morphology of the lesions is presented and discussed. We surveyed the literature regarding conditions that mimic amelanotic melanoma, and we discuss the treatment and prognosis for amelanotic melanoma. Results: Amelanotic melanoma may masquerade as a variety of other conditions leading to a delay in the diagnosis or an inappropriate biopsy technique. The prognosis of amelanotic primary tumors is no different from that for its pigmented counterpart. Conclusion: The clinician should be familiar with the presentation of amelanotic melanoma to facilitate prompt diagnosis. (J Am Acad Dermatol 2000;42:731-4.)

Section snippets

Case 1

This 52-year-old white man with no previous history of skin cancer presented with an “unusual spot” on the top of his left shoulder. The lesion was asymptomatic. The patient had seen a physician who rendered a diagnosis of basal cell carcinoma and then performed a small incisional shave biopsy that showed melanoma in situ. He was self-referred for further evaluation. On physical examination he had a few atypical nevi of his trunk. The shoulder lesion consisted of a 1.3 × 2.0-cm slightly raised

DISCUSSION

The clinical term amelanotic implies that the tumor lacks any pigmentation on visual inspection. A review of the literature suggests that the term is often used more loosely to include tumors only partially devoid of pigment. According to Guiliano, Cochran, and Morton,6 most tumors have pigmentation involving the adjacent skin; truly amelanotic lesions are rare.

Any clinical subtype of cutaneous melanoma may be amelanotic, although it is more common for this to occur in subungual tumors and in

References (21)

There are more references available in the full text version of this article.

Cited by (167)

  • Cells to Surgery Quiz: January 2022

    2022, Journal of Investigative Dermatology
  • Plantar Melanoma: An Investigation of Its Incidence

    2021, Clinics in Podiatric Medicine and Surgery
    Citation Excerpt :

    The misdiagnosis rate of all forms of acral melanoma has been cited as between 25% and 36%; however, this may be greater for acral amelanotic melanomas. Amelanotic melanoma constitutes 2% to 8% of all melanomas, but approximately 7% of amelanotic melanomas occurs on the plantar aspect of the foot.19 These lesions may be painless to the patient and can at times resemble a diabetic foot ulcer.20

  • Melanoma of the Hands and Feet (With Reconstruction)

    2021, Clinics in Plastic Surgery
    Citation Excerpt :

    Moreover, the appearance of amelanotic melanomas varies and can mimic benign and malignant conditions including hemangioma, basal cell carcinoma, squamous cell carcinoma, pyogenic granuloma, Merkel cell carcinoma, and others.24,25 The importance of improving detection of amelanotic melanoma is highlighted by the fact that these lesions present with thicker Breslow thickness, higher mitotic rate, more frequent ulceration, higher tumor stage, and lower survival than pigmented melanomas.23,25 Classically, amelanotic melanoma distribution is associated with sun-exposed areas including the dorsal aspect of the hand.23

  • Cells to Surgery Quiz: April 2021

    2021, Journal of Investigative Dermatology
  • Management of Noncutaneous Melanomas

    2020, Surgical Oncology Clinics of North America
    Citation Excerpt :

    Overall prognosis is poor for all mucosal melanomas. Patients are more likely to present with advanced disease compared with cutaneous melanoma, which may be caused by lack of early symptoms and high rates of amelanosis (25%–70%) compared with cutaneous melanoma (1.8%–8%),86,87 which adds to the difficulty in distinguishing melanoma from other more common, benign diseases. Surgical management has moved toward wide local excision (when feasible) instead of more radical procedures.

View all citing articles on Scopus

Reprint requests: Susan E. Koch, MD, Mail Code CDW1, Oregon Health Sciences University, 745 SW Gaines Rd, Portland, OR 97201-3098.

View full text