Basal cell carcinoma with halo phenomenon in a young female: significance of dermatoscopy in early diagnosis.

Halo phenomenon of nevus may be observed as a circular reaction, although it is unusual around tumors. A 29-year-old woman presented with a pigmented lesion on the cheek since three years. She noted whitening of the skin around the lesion almost after a year following its appearance. Dermatologic examination revealed a pigmented nodular lesion with a hypopigmented halo on the left infraorbital region. The clinical impression was halo nevus, whereas basal cell carcinoma (BCC) was considered in dermatoscopic differential diagnosis. The diagnosis was infiltrative-type BCC histopathologically. The persistence of a perilesional halo around an enlarging pigmented lesion should be carefully examined with accompanying dermatoscopic findings even in young patients for early diagnosis of tumoral lesions.

What was known?

Halo phenomenon is rarely observed around tumors. It has been reported in single cases of melanoma, BCC, neurofibroma, and angioma.

Introduction

Halo phenomenon of melanocytic nevus is observed as a circular reaction of hypopigmentation, although it is an unusual circumstance around tumors. It has been reported as annular leukoderma in individual cases of melanoma,[1] basal cell carcinoma (BCC), neurofibroma, and angioma.[234] The cause of this reaction remains unknown, although proposed to be either a biological event or a result of shunting of blood away from the central lesion.[2]

Case Report

An otherwise healthy, 29-year-old Caucasian woman presented with a pigmented lesion on the cheek since three years. She noted whitening of the skin around the lesion almost after a year following its appearance and spontaneous enlargement of the lesion during pregnancy, recently. She gave no history of sunburn or trauma.

Dermatologic examination revealed a 12 × 10 mm reddish brown nodular lesion surrounded by a 1 cm wide halo of depigmentation on the left infraorbital region [Figure 1]. There was no clinical evidence of scarring or inflammation in the hypopigmented halo. She had Fitzpatrick skin type 2.

Figure 1

Peripherally pigmented pinkish nodule on the face

Dermatoscopic analysis of the partially pigmented central nodule was suggestive of a nonmelanocytic lesion with the absence of pigment network, accompanied by a subtle peripheral halo of depigmentation. Peripherally localized multiple blue-gray dots and globules, a blue-gray ovoid nest, spoke-wheel areas, and arborizing telangiectasia were prominently observed [Figure 2].

Figure 2

Dermatoscopic view of the lesion in three quadrants according to Figure 1

Histopathologic characteristics of the totally excised lesion confirmed the diagnosis of infiltrative-type BCC. Melanin was observed in the squamous epithelium, and lymphocytic infiltration was present in the dermis of the neighboring tumoral region. The area of peripheral hypopigmentation showed a decrease in the number of melanophages [Figure 3].

Figure 3

Infiltrative-type basal cell carcinoma (H and E, ×100)

Discussion

Annular leukoderma is described around several benign and malignant lesions and could be mistaken as halo nevus. BCC is believed to develop hypopigmentation infrequently, and only a few cases have been reported. The previously reported three patients were older than 50 years, and BCC was located on the face in only one patient. Moreover, a history of multiple BCCs was noted in two of the patients.[24] The features of interest in our patient were young age and a usual medical history. Therefore, the initial clinical impression was halo nevus and possibly melanoma, although findings of dermatoscopy made us consider BCC in differential diagnosis. In addition, dermatoscopy was useful to rule out regressing melanoma in this case. Recently, sclerodermiform BCC appearing on a vitiliginous patch was reported in a young female.[5] Differing from our case, the depigmented patch preceded sclerodermoid BCC in this young individual.

Previously reported cases of BCC with hypopigmented halo lacked dermatoscopic findings. Dermatoscopy is a fast, simple, and advantageous procedure for differentiating between halo nevus and BCC to avoid unnecessary surgery for the patient. Although very rare, young patients with BCC as was the case, might be mistakenly followed up as halo nevus for years, if initial examination including dermatoscopy was not done. In conclusion, the persistence of perilesional halo around an enlarging pigmented lesion should be carefully examined with accompanying dermatoscopic findings even in young patients, for early diagnosis of nonmelanocytic tumoral lesions.

What is new?

The features of interest in our patient were young age and lack of a history of multiple BCCs, as was reported in a few cases previously. This case of BCC with hypopigmented halo showed distinctive dermatoscopic findings. Therefore, initial examination including dermatoscopy is mandatory, even in young patients with perilesional halo around an enlarging pigmented lesion.