Spindle Cell Squamous Carcinoma of the Esophagus: A Rare Malignancy With Biphasic Morphology

Abstract

Introduction Spindle-cell squamous carcinoma (SpCC) of the esophagus is rare and accounts for 0.1%-1.5% of all esophageal tumors. Here we report a rare case of SpCC in a patient with human immunodeficiency virus (HIV). Case Description A 59-year-old male with a past medical history of HIV (undetectable viral load, CD4+ 491) presented with a 30 pound unintentional weight loss due to odynophagia over the last 2-3 months. He has a history of heavy alcohol use and smoking. He underwent an esophagogastroduodenoscopy which showed a large ulcerated obstructing mass spanning the middle and distal esophagus. Biopsies were consistent with granulation and fibrinous exudate with a rare group of atypical squamous epithelium. Cytomegalovirus and herpes simplex virus stains were negative. Due to the non-diagnostic nature of the tissue, an EUS with a core biopsy was performed and subsequent tissue was still non-diagnostic. Due to continued symptoms and rapid growth over the next few months, he underwent an esophagogastrectomy despite no definitive diagnosis. The pathologic specimen post-operation was consistent with a biphasic squamous cell carcinoma with spindle cell features. Immunohisto-chemical staining showed squamous cells to be positive for CK5/6, EMA, p63, MCK, p40, and pankeratin consistent with squamous cell carcinoma. The spindle cells were positive for vimentin. Final diagnosis was SpCC. He has since been started on adjuvant chemotherapy with FOLFOX. Discussion SpCC is a rare biphasic tumor characterized by a large pedunculated bulky mass in the middle third of the esophagus composed of malignant spindle cells and carcinomatous components. Obstructive symptoms are often a presenting sign which allows for an earlier diagnosis and better prognosis compared to squamous cell carcinoma. The spindle cells originate from the stroma while squamous cells are on the surface which may be composed of carcinoma or dysplasia. Immunohistochemical analysis is necessary for the diagnosis of both carcinomatous and sarcomatous features. Biopsy samples are often non-diagnostic because of insufficient size, depth, and they often miss the cellular components needed for diagnosis. Given the rarity of the diagnosis, there is no consensus on treatment modalities with radiation and chemotherapy. If symptomatic, surgery is often first line and is often curative if diagnosed early.1707_A Figure 1. SpCC on retroflexion with tumor extending into the cardia1707_B Figure 2. SpCC in mid esophagus