Red Dot Basal Cell Carcinoma: Literature Review of a Unique Clinical Subtype of Basal Cell Carcinoma.

Abstract

Red dot basal cell carcinoma is a distinctive clinical subtype of basal cell carcinoma. It has been reported in eight individuals with a male to female ratio of 1:1; and the patients’ ages ranged from 50 to 74 years. All patients had prior history of actinic keratoses and basal cell carcinoma. In addition, some patients also had prior squamous cell carcinoma, malignant melanoma, and/or dysplastic nevus. The tumor was usually of recent onset, asymptomatic, and on sun-exposed skin. It was most commonly located on the nose (five patients); other sites were the upper lip, the mid back, or thigh—each in one patient. The red dot basal cell carcinoma was solitary and small—usually 4 mm or less in diameter. It typically presented as a red macule or papule; however, it sometimes appeared as a flesh-colored or pink to light-red papule with a bright-red central area. Microscopic features showed basaloid tumor cells (arranged as either nodular aggregates or superficial buds or both). In the central portion of the lesion, there was a proliferation of erythrocyte-containing vascular spaces between the epidermis and the neoplasm. The basal cell carcinoma pathology subtype was either nodular and superficial (three patients), nodular (two patients), or superficial (one patient). The clinical differential diagnosis of red dot basal cell carcinoma included not only benign vascular lesions (such as hemangioma and telangiectasia) but also inflammatory conditions and adnexal tumors. Other basaloid cell neoplasms were in the pathologic differential diagnosis. The pathogenesis of red dot basal cell carcinoma is similar to that of other basal cell carcinoma clinical subtypes. Mohs surgery is the treatment of choice for red dot basal cell carcinomas. Red dot basal cell carcinoma has two categories of biologic behavior based on the ratio of the postoperative wound size as compared with the size of the preoperative tumor: nonaggressive (for which the ratio was 5:1 or less for three patients) and aggressive (for which the ratio was greater than 12:1 for three patients). There was no recurrence of the red dot basal cell carcinoma after treatment. In conclusion, the incidence of red dot basal cell carcinoma—a unique morphologic variant of basal cell carcinoma—may be higher than suggested by the number of reported patients with this basal cell carcinoma subtype.