[Cutaneous basosquamous cell carcinoma]

Basosquamous carcinoma (BSC) is a rare malignancy with specific histopathological features of both basal cell (BCC) and squamous cell carcinoma (SCC). Therefore, the histological diagnosis is challenging. Due to its low incidence there is no consensus on the surgical management of BSC.

We describe the (immunohistological) diagnostic and therapeutic aspects of nine cases (8 male symbol : 1 female symbol, on average 68.6 years of age (range: 47-81)) of BSC. Of these, seven were located on the pinna, one on the forehead and zygomatic region and one in the retroauricular region.

Immunochemical staining for epithelial membrane antigen was negative (apart from the typical areas of epithelial pearl formation) and BerEP4 was positive in all cases. Therapy consisted of partial removal of the pinna in four, and total removal in three cases. One patient was treated by partial removal of the auricle with superficial parotidectomy and ipsilateral neck dissection. In the case of the carcinoma on the forehead, a local excision was performed. The median follow-up was 45 months. One patient had a local recurrence.

The histological diagnosis of BSC is confirmed by the use of EMA and BerEP4 immunohistological staining. Clinically, BSC is a rare, aggressive skin tumor. Despite the histological similarity to basal cell carcinoma, BSC has an imminent risk of metastasizing. Hence, therapy should be similar to that for SCC, taking into consideration the age and general state of the usually elderly patient.