Applied Evidence

10 derm mistakes you don’t want to make

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Patient care can suffer—or be delayed—by these common mistakes. Here’s how to avoid them.


 

References

I’ve seen my share of missed diagnoses over the years while caring for patients who, through physician- or self-referral, have made their way to our multi-specialty group practice where I focus solely on skin.

There was the 93-year-old patient whose “sun spot” had been evaluated and treated by 2 different dermatologists in the past and turned out to be a lentigo maligna melanoma (FIGURE 1).

There was the patient who had a lesion on her lip for “at least 10—maybe 20—years” that neither caught the attention of her physician, nor her dentist (FIGURE 2). Histology showed she had an infiltrative basal cell carcinoma.

And then there was the wife of a healthcare professional who decided she wanted a “second opinion” for the asymptomatic lesion on her leg that her husband assured her was benign. Her diagnosis was not so simple: She had a MELanocytic Tumor of Unknown Malignant Potential (MELTUMP) that required careful follow-up (FIGURE 3).

Early detection, as we all know, is the name of the game when it comes to skin malignancies. Yet every day, opportunities to catch small, early lesions are missed.

During the past couple of years, I’ve had thousands of patient visits for skin problems and diagnosed more than 1000 skin malignancies. The majority of patients have had some treatment for their presenting dermatosis prior to arrival. Based on my experiences with these patients, I’ve developed a list of common dermatology “mistakes.” Here they are, with some tips for avoiding them.

FIGURE 1
Melanoma missed by 2 dermatologists


This “sun spot” was of no concern to the 93-year-old patient because she had been evaluated and treated by 2 different dermatologists. The darkest areas are dermoscopically-directed pen markings for incisional biopsy. (The size of the lesion and proximity to the eye precluded primary excisional biopsy.) This “sun spot” turned out to be lentigo maligna melanoma.

FIGURE 2
Lesion on lip for “10—maybe 20—years”


This patient had a lesion that had been on her lip for “at least 10—maybe 20—years.” The patient said it had never bled or crusted. Telangiectasia, pearliness, and some infiltration were present. Histologic diagnosis: infiltrative basal cell carcinoma.

FIGURE 3
A case of MELTUMP


Two dermatopathologists read the biopsy as Spitzoid malignant melanoma, Clark Level III, and Breslow thickness 0.9 mm. Two independent dermatopathologists read the same original slides in consultation as atypical Spitz nevus. The 4 could not reach agreement. Final clinical diagnosis: MEL anocytic Tumor of Unknown Malignant Potential (MELTUMP).

Mistake #1: Not looking (and not biopsying)

I had a woman come into the office to have a lesion assessed. She had seen a dermatologist a couple of weeks earlier and even had a number of lesions removed during that visit. The patient told me that she’d repeatedly tried to show the dermatologist one specific lesion—the one of greatest concern to her—just below her underpants line, but the physician was in and out so fast each time, she never had the chance to point out this one melanocytic, changing lesion.

The lesion turned out to be a dysplastic nevus with severe architectural and cytologic atypia. This type of lesion requires histology to differentiate it from melanoma, and could just as easily have been a melanoma.

Almost daily I treat patients who are being seen by their primary care physicians regularly, and have obvious basal cell carcinomas (BCC) or squamous cell carcinomas. I have even found skin malignancies on physicians, their spouses, and their family members.1 These lesions can be easily missed—if you don’t look carefully.

Consider, the following:

  • FIGURE 4 illustrates a superficial BCC on the forearm of a physician who was totally unaware of it. (It was detected on “routine” skin examination.)
  • FIGURE 5 illustrates a BCC on a patient’s central forehead that, by her history, had been there for many years, and was not of any concern to her. The patient was referred to our office for evaluation of itchy skin on her legs.
  • FIGURE 2 illustrates a lesion that, according to the patient, had been on her lip for at least 10—and perhaps even 20—years and was of no concern to her. (It was not the reason for the visit.) Over the years, this patient certainly had numerous primary care and dental visits, but no one “saw” the lesion. Histology confirmed the clinical impression of BCC.

FIGURE 4
Superficial BCC on physician’s forearm


A physician asked for a skin examination, but was totally unaware of this asymptomatic lesion on his dorsal forearm. Once it was identified, he could provide no history about its duration. The lesion had never bled or crusted. Pathology confirmed that it was a superficial basal cell carcinoma.

FIGURE 5
“Mole” on forehead for many years


This patient was referred for itchy legs. She was unconcerned about a prominent “mole” noted on examination of her forehead, one that she said had been there, unchanged, for many years. Histology confirmed nodular basal cell carcinoma.

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