Basal cell adenocarcinoma of the parotid gland: a rare tumor entity. Case report and review of the literature

Basal cell adenocarcinoma is a ra re entity that was first defined as a malignant salivary gland tumor in 1991. We present another case report and discuss pathology, pathogenesis, differential diagnosis, therapy and prognosis on the basis of currently available literature. Although histomorphologic features of the tumors are similar to basal cell adenomas, proof of an infiltrative-and destructive growth is essential for diagnosis. Adenoid cystic carcinoma and basaloid squamous carcinoma must also be considered in any differential diagnosis. Tumor development within a pre-existing basal cell adenoma and de novo development are discussed. Most of the tumors appear to be benign clinically. Facial pain is rare and facial nerve palsy was noted in only one case. Metastases have occurred in less than 10% of patients, with only one involving the lung. Due to their biologic behavior and prognosis, basal cell adenocarcinomas should be classified as low-grade carcinomas. The therapy of choice is parotidectomy with preservation of the facial nerve. Neck dissection has to be added in cases with cervical metastases. Radiation is advisable in patients with recurrent disease. Since there is a nearly 30% local recurrence rate, intensive follow-up is necessary.