Red Dot Basal Cell Carcinoma: An Unusual Variant of a Common Malignancy
May 2016 | Volume 15 | Issue 5 | Case Reports | 645 | Copyright © May 2016
Tiffany Y. Loh BS and Philip R. Cohen MD
University of California San Diego, San Diego, CA
BACKGROUND: Red dot basal cell carcinoma is a distinct but rare subtype of basal cell carcinoma (BCC). It presents as a red macule or papule; therefore, in most cases, it may easily be mistaken for a benign vascular lesion, such as a telangiectasia or angioma.
PURPOSE: A red dot BCC in an older woman is described. Clinical and histological differences between red dot BCCs and telangiectasias are described.
METHOD: A 72-year-old woman initially presented with a painless red macule on her nose. Biopsy of the lesion established the diagnosis of a red dot BCC. Pubmed was searched for the following terms: angioma, basal cell carcinoma, dermoscope, diascopy, red dot, non-melanoma skin cancer, telangiectasia, and vascular. The papers were reviewed for cases of red dot basal cell carcinoma. Clinical and histological characteristics of red dot basal cell carcinoma and telangiectasias were compared.
CONCLUSION: Red dot BCC is an extremely rare variant of BCC that may be confused with benign vascular lesions. Although BCCs rarely metastasize and are associated with low mortality, they have the potential to become locally invasive and destructive if left untreated. Thus, a high index of suspicion for red dot BCC is necessary. J Drugs Dermatol
Basal cell carcinoma (BCC) is the most common type of malignancy diagnosed in the United States. Although BCCs generally do not metastasize and are associated with a low mortality rate, they may become locally invasive if left untreated, leading to significant tissue destruction and potential disfigurement.1,2
Several subtypes of BCC have been described in the literature, including nodular, infiltrative, morpheaform, superficial, and pigmented BCC.3,4 We present a woman who had an unusual variant of BCC, termed “red dot” BCC, which has seldom been described in the literature.5-7 We also summarize the features that differentiate red dot BCCs from telangeictasias, since the latter is a benign vascular lesion which morphologically mimics red dot BCCs.
A 72-year-old woman with a history of BCC and squamous cell carcinoma presented for a complete skin examination and was found to have a red macule on her distal left nasal bridge. A glass slide was used to apply pressure to the lesion; the macule blanched with diascopy, which was consistent with telangiectasia; therefore, a decision was made to observe and closely monitor the lesion. Three months later, the patient again presented for evaluation of the lesion; however, she mentioned that there was occasional bleeding from the site.
Cutaneous examination revealed a red macule on the distal left nasal bridge measuring 1x1 mm, with an underlying
superficial 2x3 mm flesh-colored papule (Figure 1). A biopsy was performed. Microscopic examination showed small nodular aggregates of basaloid tumor cells extending from the epidermis into the reticular dermis. Several dilated blood vessels and occasional extravasated erythrocytes were present in the papillary dermis (Figure 2). Correlation of the clinical morphology and pathologic findings established the diagnosis of red dot BCC.
The patient subsequently underwent Mohs micrographic surgery, and the tumor was removed in two stages. The final post-operative size was 10x10 mm. The wound was repaired with a full-thickness skin graft. Follow up examination one week later showed excellent healing of the surgical site and no evidence of recurrence.
Nodular BCCs classically present as waxy papules with central depression and pearly appearance.1 The papule may have telangiectasias on the surface or have a rolled border with central ulceration. Very rarely, BCCs may present as an uncommon “red dot” variant, which may mimic benign vascular lesions such as telangiectasias, and thus present a point of diagnostic confusion (Table 1).
Diascopy is a test for blanchability that is usually performed using a glass slide.8 This test may not be a reliable method of differentiating between red dot BCC and telangiectasias, as