S1981 Beyond SCC: Basaloid Squamous Cell Carcinoma of the Esophagus

Abstract

INTRODUCTION: Basaloid squamous cell carcinoma (BSCC) is an aggressive and poorly differentiated variant of squamous cell carcinoma that has both basaloid and squamous components. Its first description suggests that the tumor originates from totipotential cells in the basal layer of squamous epithelium. CASE DESCRIPTION/METHODS: A 57-year old African American female with a history of chronic GERD and stroke was referred for 3 months of dysphagia to solids, a weight loss of 30 lbs, and abnormal barium swallow. She denied alcohol use and smoking. Barium swallow from the referring facility showed segmental narrowing and a long irregular distal esophageal stricture. Upper endoscopy revealed a circumferential ulcerated mass at 25 cm up to 32 cm from the incisors, preventing passage of the adult gastroscope. This was exchanged for a pediatric gastroscope. A patch of nodular mucosa with ulceration was seen at 23 cm from the incisors. Pathology showed moderately to poorly differentiated basaloid squamous cell carcinoma. DISCUSSION: BSCC is predominantly seen in the upper aerodigestive tract (nasopharynx, tongue, larynx, trachea), where it can be associated with human papillomavirus (HPV). Esophageal BSCC is very rare, accounting for only 0.068-4.0% of esophageal carcinomas, and its associated with HPV is less certain. Patients with esophageal BSCC are older, have higher proliferative activity, and higher apoptotic indices when compared to typical squamous cell cancer of the esophagus. Like our case, patients with esophageal BSCC often present with dysphagia and weight loss. On endoscopy, deeply invasive, large bulky ulcerated fungating masses are seen. Histologically, BSCC consists of small basaloid cells with oval to round nuclei, pale chromatin, and scant basophilic cytoplasm. The cells are arranged in solid or cribriform lobules with comedo-necrosis. On immunohistochemistry stains, there is poor reactivity for cytokeratin 13 and 14, antibodies that are typical of squamous cell epithelia. Widespread metastases are usually present upon diagnosis. However, if curative resection is possible, the prognosis of patients with esophageal BSCC is similar to that of patients with typical SCC.Figure 1.: Proximal end of the esophageal tumor.Figure 2.: Distal end of the esophageal tumor.