Case report of a basaloid squamous epithelial carcinoma of the oropharynx: clinical and histopathologic markers of an aggressive tumor entity

Abstract

Basaloid squamous cell carcinoma is a variant of squamous cell carcinoma which is located predominantly in the upper aerodigestive tract. The cardinal histopathologic feature is a biphasic cellular pattern of basaloid and squamous components in a close relationship. Major differential diagnoses include adenoid cystic, adeno, squamous, adenosquamous, and basal cell carcinomas. This entity may commonly pose diagnostic difficulties, especially on small biopsy material, if only the basaloid component of the tumor is included. A tumor of the oropharynx (T2) was detected in a 61-year-old man. After endoscopic biopsy, this tumor was histologically identified as an adenocarcinoma. A very rapid tumor growth became obvious during the patient's staging. After pharyngectomy and neck dissection, the histopathological diagnosis was corrected to a basaloid squamous cell carcinoma. The definite diagnosis was not made on biopsy material, because only the basaloid component of the tumor was included. Basaloid squamous carcinoma is a biologically aggressive tumor with high proliferative activity and a propensity to destructive local growth and early regional and distant metastasis. Literature predominantly indicates that basaloid squamous cell carcinoma is an aggressive variant of squamous cell carcinoma and is prognostically worse than the regular squamous cell carcinoma. Because of the aggressive biological behavior of basaloid squamous cell carcinoma, radical surgery combined with radiation and chemotherapy is the treatment of choice.