Melanoma quiz: Diagnosis, differential and black patches

A 71-year-old Caucasian woman with blue eyes and fair skin presents with an asymptomatic 4 cm x 2.5 cm black patch that has been present for a few years.

Figure 1

ANSWER

3. Melanoma

The picture shows several features of a melanoma, which can often be clinically suspected using the ABCDE rule. A stands for asymmetry (one half is not like the other); B stands for border (irregular, scalloped, or poorly defined); C stands for Color (variegated with intermixed areas of tan, brown, or black, and sometimes red, white, or blue); D stands for diameter (greater than 6 mm when diagnosed); E stands for evolving (changing in size, shape, or color) (1).

Figure 1

ANSWER

3. Excisional biopsy

Definitive diagnosis of a clinically suspicious melanoma is done with a biopsy of the cutaneous finding. Clinically suspected malignant melanoma should be immediately managed if possible with full-thickness excision biopsy to allow for diagnosis and staging. Partial punch and shave biopsies that do not capture the entire lesion can result in erroneous staging, but in cases with large lesions or in cosmetically/functionally crucial locations, may be necessary (2).

Figure 1

ANSWER

6. All of the above

Various risk factors have been identified for the development of cutaneous melanoma. These include tendency of the skin to sunburn after exposure to ultraviolet radiation; light hair and eye color; freckling; fair skin types (Fitzpatrick’s 1-3 out of 6 types), increased number of melanocytic nevi, presence of dysplastic nevi, solar or actinic keratosis, experience of severe sunburns before age 16, exposure to tanning beds and personal or family history (one or more affected first-degree relatives) of melanoma (3).

Figure 1

ANSWER

2 and 4: Regression of color and ulceration or bleeding

Clinically, upon dermoscopy, regression refers to scar-like areas, often seen with granularity or peppering (4).  Areas of depigmentation are seen within or around the melanoma, and the color may be blue, red, white, or gray (5).  Histologically, regression refers to presence of an infiltrate of lymphocytes admixed with pigment-laden macrophages underlying an atrophic epidermis with flattened rete ridges (4). Essentially, the dermal portion at the center of the tumor is replaced by fibrous stroma (5). 10 to 35% of all primary cutaneous melanomas show regression, and it is most commonly found in thin melanomas.  Although somewhat controversial, this finding is believed to be an indicator of poor prognosis for cutaneous melanoma (5).  Ulceration, defined histologically as the absence of intact epidermis overlying a considerable part of the primary tumor, is a poor prognostic factor. The presence of ulceration reduces survival in all tumor thickness categories, with a 4% decreased 5-year survival rate in thin tumors and up to 22% decreased 5 year survival in thick tumors greater than 4.0 mm (6). Bleeding, ulceration or discomfort are late signs of a changing mole and are signs of a worse prognosis (7).

A Caucasian patient presented with this dark black, crusted plaque on the right toe that appeared overnight.

Figure 2

ANSWER

4. Scrape lesion off with a blade without anesthesia

The lesion was easily scraped off of the toe without anesthetic. In the image above, at approximately 7 o’clock location on lesion, it has been partially scraped to reveal normal underlying skin.

Figure 2

ANSWER

2. Subcutaneous heloma or hematoma

The image shows a subcutaneous hematoma or heloma.  Although the appearance may be concerning for malignant melanoma, under close examination both clinically and dermoscopically, the lesion displays hemorrhage and no pigment.  This is supported by the fact that it could be easily scraped off.  A subcutaneous hematoma can mimic a melanoma, and it is important to recognize the difference between them (8).   Unlike melanoma, a traumatic hematoma usually appears suddenly and resolves in a days to weeks, or even months in a subungual location, unlike a melanoma (7).

An elderly Caucasian patient presents with this dark stuck-on black asymptomatic plaque.

Figure 3

ANSWER

3. Seborrheic keratosis

The clinical differential diagnoses of melanoma includes seborrheic keratoses, traumatized or irritated nevus, pigmented basal cell carcinoma, lentigo, blue nevus, angiokeratoma, traumatized hematoma, venous lake, hemangioma, dermatofibroma, and pigmented actinic keratosis. Seborrheic keratoses often have a “stuck-on” and cerebriform appearance, are often symmetric, and are multiple on an individual (7). Some lesions crumble off with or without trauma, as seems likely in the image above.  Collision lesions of pigmented benign tumors could also be a simulator of melanoma (9).

Figure 3

ANSWER

1. Observation

They are itchy, bleeding, painful, they can be removed via curettage and desiccation or shave removal.  If there is any question of the etiology, histologic specimen should be sent for confirmation of the identity of the lesion. In these cases, a shave is preferred to a curetting of the lesion, as it maintains morphology and aids in full diagnosis (10).

REFERENCES

American Academy of Dermatology Ad Hoc Task Force for the ABCDEs of Melanoma, Tsao H, Olazagasti JM, et al. Early detection of melanoma: reviewing the ABCDEs. J Am Acad Dermatol. 2015 Apr;72(4):717-23.

Tadiparthi S, Panchani S, and Iqbal A. Biopsy for Malignant Melanoma – Are We Following the Guidelines? Ann R Coll Surg Engl. 2008 May; 90(4): 322–325.

Bränström R, Chang Y, Kasparian N, et al. Melanoma Risk Factors, Perceived threat and Intentional Tanning: An Online Survey. Eur J Cancer Prev. 2010 May; 19(3): 216–226.

Ribero S, Moscarella E, Ferrara G, et al. Regression in cutaneous melanoma: a comprehensive review from diagnosis to prognosis. J Eur Acad Dermatol Venereol. 2016 Jul.

Requena C, Botella-Estrada R, Traves V, et al. Problems in Defining Melanoma Regression and Prognostic Implication. Actas Dermosifiliogr. 2009;100:759-66

Homsi J, Kashani-Sabet M, Messina JL, et al. Cutaneous melanoma: prognostic factors. Cancer Control. 2005 Oct;12(4):223-9.

Goldstein BG and Goldstein AO. Diagnosis and Management of Malignant Melanoma. Am Fam Physician. 2001 Apr;63(7):1359-1369.

Fountain JA. Recognition of subungual hematoma as an imitator of subungual melanoma. J Am Acad Dermatol. 1990 Oct;23(4 Pt 1):773-4.

González-Vela MC, Val-Bernal JF, González-López MA, et al. Collision of pigmented benign tumours: a possible simulator of melanoma. Acta Derm Venereol. 2008;88(1):92-3.

Jackson JM, Alexis A, Berman B, et al. Current Understanding of Seborrheic Keratosis: Prevalence, Etiology, Clinical Presentation, Diagnosis, and Management. J Drugs Dermatol. 2015 Oct;14(10):1119-25.