Basal cell carcinoma and squamous cell carcinoma in a single tumor in the anterior auricular area

Abstract

The concurrence of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) in a single tumor is rarely encountered. We report a case of BCC and SCC in a single tumor in the anterior auricular area. A 70-year-old woman had been diagnosed with BCC by a punch biopsy performed at a dermatology clinic. We performed wide excision of the tumor with an ulcer in the anterior auricular area. Analysis of the biopsy specimen revealed the presence of both BCC and SCC in the tumor. This case illustrates that it is necessary to establish a precise diagnosis and formulate appropriate surgical and treatment plans considering the possibility that two carcinomas may coexist, although the possibility is low in patients with skin cancer.

Keywords: Basal cell carcinoma; Co-existence; Squamous cell carcinoma.

Fig. 1.

Preoperative photograph. A solitary mass in the preauricular area in a 70-year-old woman.

Fig. 2.

Intraoperative photograph. The resected specimen measured approximately 1.6 × 1.4 × 0.5 cm.

Fig. 3.

Photomicrograph of the specimen. The blue arrow shows nests of typical squamous epithelial cells extending to the dermis and forming keratin pearls. The squamous cell carcinoma (SCC) was well-differentiated and had clear margins. The red arrow of the image shows basal cell carcinoma cells where basaloid epithelium was clearly separated from SCC and typically formed palisades. It should be noted that these two cells were clearly separated rather than being observed a tumor composed of two distinct populations of cells that are intermingled, as observed in basosquamous carcinoma (H&E, × 100).