Basaloid squamous cell carcinoma of the head and neck: A clinicopathologic and flow cytometric study of 10 new cases with review of the English literature

Abstract

Introduction: We describe the clinicopathologic and flow cytometric features of 10 cases of basaloid squamous cell carcinoma (BSCC) of the head and neck to determine if DNA ploidy is a useful prognostic indicator. We also provide a review of 80 cases previously reported in the English language literature.

Materials and Methods: The 10 cases were obtained from the surgical pathology files of Presbyterian University Hospital and The Eye and Ear Institute, Pittsburgh, PA (1987–1991). In all 10 cases, the microscopic slides and clinical data were reviewed. Flow cytometry was performed using the Hedley technique and formalin-fixed, paraffin-embedded tissue.

Results: The mean age of patients with BSCC was 64 years (range, 49 to 75 years). Tumor involved the base of tongue (n = 5), hypopharynx-epiglottis (n = 3), and tonsil (n = 1). One case presented with cervical lymph node metastasis from an unknown primary site. Histologically, BSCC showed a biphasic pattern with basaloid-squamous elements, comedonecrosis, stromal hyalinization, surface dysplasia, and an in situ and/or invasive squamous cell carcinoma component. Flow cytometry revealed six diploid and four aneuploid tumors. Five of six patients with diploid and all four patients with aneuploid tumors developed early regional and/or distant metastases. Of the two patients who died of disease, one had a diploid and the other an aneuploid tumor.

Conclusion: Our study reaffirms the predilection of BSCC for the base of tongue, pyriform sinus, and supraglottic larynx, and its aggressive biologic behavior with a high incidence of cervical lymph node metastasis (64%), distant spread (44%), and death from disease (38% mortality at 17 months median follow-up). However, in contrast to previous reports, tumor ploidy by flow cytometry provided no additional prognostic information beyond that supplied by routine histologic evaluation.