Oncology (General Cancer)/Concerned about melanoma


Hello dr. Higby,

At 30 I had a growth removed from my colon which contained a substantial area of high grade dysplasia. That was quite a scare, and I've been more vigilant about my health since.

I am 34 years old now and a few months ago I noticed a mole on the sole of my left foot that had not been there before. It was 5mm in diameter, brown, with a distinct black area contained within. I do have a high number of moles on my body, of which several dysplastic, so I was referred to the dermatologist.

The dermatologist removed the mole with a 5mm punch and had it sent to the lab. After this visit I grew concerned and started reading about acral lentiginous melanoma (ALM). Needless to say, what I read was not very reassuring. All of it boils down to two specific concerns that I have been very, very worried about since:

1. I read that early ALM is histologically nearly indistinguishable from an acral nevus. The most reliable way to differentiate between them is the dermoscopic appearance of a 'parallel ridge' pattern in ALM. [1]
2. Black areas are extremely uncommon in plantar nevi, yet a common feature of ALM. [2]

At the follow-up appointment with my dermatologist I've voiced these concerns. She said the lab results showed a nevus containing inflamed cells. She couldn't answer my question about the dermoscopic appearance and told me I shouldn't be worried because it has been ruled out that the lesion was malignant.

Based on what I read I am very concerned about a false negative. I know I'd feel alot better if the mole was excised with a margin, just in case.
I'd be very appreciative of your opinion. Am I being prudent or just way out there?

Thank you for your concern,


[1] Histological Diagnosis of Nevi and Melanoma. Guido Massi, Philip E. LeBoit. Chapter 45.2, page 634
[2] Acral Melanocytic Nevi, Prevalence and Distribution of Gross Morphologic Features in White and Black Adults. Gary A. Palicka, BS; Arthur R. Rhodes, MD, MPH. Table 3, 4.

While a nevus and lenticular melanoma share some macroscopic characteristics, ultimately the decision as to whether a lesion is malignant or not depends on the microscopic observation.  Before I would go around looking for someone to do a wide margin excision, I"d have the tissue reviewed by a melanoma expert.  In oncology we do that when there is a question.  There may be no question in your case, but you could ask your dermatologist to do this to reassure you, since you have read about these things and are worried.  Bottom line, if you were diagnosed in the USA and there is a pathology department in your hospital that meets the standards set out by the American Society of Pathologists, you are probably ok.  One of the standards is that tissues submitted need to be studied by one pathologist and confirmed by another.  If there is disagreement a third party needs to be brought in.  This all has to be documented.  Oddly enough I had a similar thing happen to me when I was much younger.  I had a lesion on my thigh, which I knew objectively was benign, but still it kept me up at night.  So I asked a surgeon friend to remove it.  I slept much better.  Hope this helps.  

Oncology (General Cancer)

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Donald Higby, M.D.


I can answer almost all questions related to the treatment and natural course of most kinds of cancer, especially cancers of prostate, colon, lung and breast.


I have been a practicing medical oncologist for 36 years, and have been chief of service at a major medical center for 25 years. I've also done research in cancer treatments.

American Society of Clinical Oncology

New England Journal of Medicine American Journal of Medicine Journal of the American Society of Clinical Oncology Hematology Transfusion Medicine

MD, Stanford University Internal Medicine residency, St. Louis University School of Medicine, St. Louis, MO Medical Oncology Fellowship, Roswell Park Cancer Institute, Buffalo, NY

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America's Best Physicians, last 14 years

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