Pigmented basal cell carcinoma mimicking a malignant lentigo melanoma in black female patient

Received on: 12/02/2010
Approved on: 14/06/2010

This study was carried out at the Hospital
Universitário Pedro Ernesto da Universidade
Estadual do Rio de Janeiro (UERJ) – Rio de
Janeiro (RJ), Brazil.

Conflicts of interests: none
Financial support: none

Abstract

A case of pigmented basocellular carcinoma clinically mimicking a malignant lentigo melanoma in the temporal region of a black female patient is reported. Basal cell carcinoma rarely occurs in black patients. When present, however, it is the second most common malignant skin neoplasia, and is usually pigmented. When the face is affected in such patients, it is difficult to differentiate between malignant lentigo melanoma and basal cell carcinoma. Dermatoscopy is a very helpful diagnostic tool in these cases.

Keywords: CARCINOMA, BASAL CELL, MELANOMA, DERMOSCOPY

Basal cell carcinoma (BCC) is a malignant neoplasia derived from non-keratinized cells that originate in the epider- mis'''''''' basal layer. If not treated, local invasion can occur, resulting in substantial tissular destruction, which can damage the skin''''''''s function and appearance. Metastases are extremely rare and occur more frequently in men over 40 with fair skin. 1 It is uncommon in black people, however the pigmented subtype is the most common type found in those patients, which hinders its clinical and differential diagnosis regarding other tumors. Dermatoscopy is a useful resource in such cases. 2-5

We report the case of a 77-year-old black female who pre- sented with a lesion in the right temporal region that appeared approximately ten years before, which had grown progressively during the previous year. In the clinical examination, it appeared as a darkened macule, with different colors and irregular shape, measuring approximately 4 x 3 cm (Figure 1).

Due to the suspicion that the lesion was a BCC or lentigo maligna melanoma, dermatoscopy was carried out, which revealed a darkened lesion with leaf-like border in its periph- ery (Figures 1 and 2). The histologic examination found basa- loid tumorous cells, with peripheral palisading and retraction of the collagen extending over the epidermis. Melanin was seen inside the tumor, which helped confirm a superficial pigment- ed BCC diagnosis (Figure 4).

Only 1.8% of BCCs occur in black people; their higher levels of epidermal melanin provide a degree of photoprotec- tion.2-4 BCCs are the second most frequent type of skin can- cers affecting blacks. 2-4 Nonetheless, when affected by some type of skin cancer, black individuals are more likely to present advanced stages of the disorder and have a greater mortality than whites. This disparity is probably due to a tendency for late diag- nosis or a higher biological aggressiveness of tumors. 2-4

Most BCC lesions are asymptomatic at the time of diagno- sis; clinical features are similar for all ethnicities. Since exposure to the sun is the most frequently involved etiologic factor, pho- toexposed areas are usually the most affected, with rare occur- rences in photoprotected areas. In general, a lesion occurs as a solitary translucent nodule that can ulcerate. 1-4 In blacks, pig- mentation is present in more than 50% of tumors, which hin- ders diagnosis and potentially generates confusion with pig- mented seborrheic keratosis, melanoma or melanocytic nevus. 2-4 The patient presented a darkened and asymmetric macule – clinical signs that suggest melanoma. Dermatoscopy is a valuable complementary method in such cases. As is characteristic in pig- mented BCCs, the patient''''''''s macule presented structures such as leaf-like border and ovoid globules; telangiectasias and arbori- form vessels were more difficult to verify. 5 The diagnosis was confirmed by a histologic examination.

In Brazil, where the ethnicities are very mixed, knowledge of the clinical features of cutaneous tumors in black patients is extremely important for correctly diagnosing and planning treatment for lesions.

References

1 . Freedberg IM, Eisen AZ, Wolff K, Austen KF, Goldsmith LA, Katz SI, editors. Fitzpatrick''s Dermatology in General Medicine. 7th. New York: McGraw – Hill; 2008.

2 . Bradford PT. Skin Cancer in Skin of Color. Dermatol Nurs. 2009; 21(4):170-8.

3 . Jackson BA. Nonmelanoma Skin Cancer in Persons of Color. Semin Cutan Med Surg. 2009; 28(2):93-5.

4 . Gloster Jr HM,Neal K.Skin Cancer in Skin of Color. J Am Acad Dermatol. 2006; 55(5):741-60.

5 . Stoltz W e col. Atlas colorido de dermatoscopia. 2º ed. Rio de Janeiro: Di Livros; 2002.