Acral Lentiginous Melanoma, often abbreviated as ALM, occurs on the palms of hands, on the soles of the feet or under the nails.
About 5% of all melanomas are this type in white patients. However, in dark skinned persons, Asians, black and Hispanic patients 50 to 60 % may have this type. Acral lentiginous melanoma occurs in older people with an average age of the mid 60’s. It usually starts with a large lesion of 3 cm or larger on the sole of the foot. It looks first like a tan or brown flat stain, appears disorganized with irregular borders.
A small percentage may not be pigmented at all and could be mixed up with a benign granuloma with a flesh color appearance. As these lesions take only a few months or up to 2 ½ years before they metastasize, it is important to see a physician and plastic surgeon as soon as possible. About 2% of white people develop this type of melanoma under the nail of a finger or toe.
This is called “subungual”melanoma. In more than 75% of these cases the growth occurs under the big toe or the thumb. Dark-skinned patients develop this much more often. The most common sign is a brown or black discoloration under the nail bed without a history of trauma.
This is a clue for all of us: to look at our nails from time to time and see your physician when there is something suspicious developing under the thumb or great toenail or under any nail at all. The worst that can happen is that the physician would suggest the removal of the nail under a local aesthetic and to biopsy the lesion and eventually refer you to a plastic surgeon. However, without this treatment early on future therapeutic steps would have to become more aggressive and might even have to include amputation of a toe or a leg depending on how advanced the tumor is. Unfortunately, this type of tumor is more aggressive than the lentigo maligna melanoma and tends to metastasize early.
References:
1. Cancer: Principles &Practice of Oncology, 4th edition, by V.T. De Vita,Jr.,et. al J.B. LippincottCo.,Philadelphia, 1993.Vol.2: Chapter on Cutaneous melanoma.
2. The Merck Manual, 7th edition, by M. H. Beers et al., Whitehouse Station, N.J., 1999. Chapter 126, p. 843-845.
3. Cancer: Principles&Practice of Oncology. 5th edition, volume 2. Edited by Vincent T. DeVita, Jr. et al. Lippincott-Raven Publ., Philadelphia,PA, 1997. Chapter on Cutaneous melanoma.
4. SA Rosenberg et al. Ann Surg 1998 Sep 228(3): 307-319.
5. SA Rosenberg Nature 2001 May 17;411(6835):380-384.
6. T Todo et al. Proc Natl Acad Sci U S A 2001 May 15 ( page not available yet).
7. GJ Tsioulias et al. Ann Surg Oncol 2001 Apr;8(3):198-203.
8. Conn’s Current Therapy 2004, 56th ed., Copyright © 2004 Elsevier
9. Ferri: Ferri’s Clinical Advisor: Instant Diagnosis and Treatment, 2004 ed., Copyright © 2004 Mosby, Inc
