Esophageal Squamous Cell Carcinoma In Situ Overlying Leiomyoma Mimicking Invasive Cancer: A Brief Case Report

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/ by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Leiomyoma is the most common benign submucosal mesen-chymal tumor of the esophagus, and squamous cell carcinoma is most common epithelial tumor of the esophagus. However, esophageal squamous cell carcinoma overlying leiomyoma has rarely been reported. Herein, we report a case of esophageal squamous cell carcinoma in situ overlying leiomyoma. In addition , we reviewed other reported cases of esophageal squamous cell carcinoma overlying leiomyoma. An asymptomatic 53-year-old man underwent esophagogas-troduodenoscopy as a health checkup. Esophagogastroduode-noscopy revealed an elevated mass, 1.8 cm in diameter, with irregular central small erosion in the upper thoracic esophagus. The lesion was clearly identified as a nonstaining area by Lugol's iodine solution (Fig. 1A). By the endoscopic biopsy, the lesion was diagnosed as squamous cell carcinoma in situ with the additional comment of not being able to encounter definite invasion due to the shallowness of the biopsy. The patient underwent subtotal esophagectomy, and a 1.8×1.6-cm-sized, elevated, nodular lesion was identified (Fig. 1B) with a well demarcated, white, solid cut surface (Fig. 1C). The scanning view of the le-sion showed a well demarcated submucosal mass with an over-lying abnormal epithelial lesion (Fig. 1D). Microscopically, the lesion was a submucosal spindle cell tumor with overlying squamous cell carcinoma in situ (Fig. 2A). Immunohistochemi-cally, the squamous cell carcinoma in situ was strongly positive for p53 (Fig. 2B). The submucosal tumor showed low cellulari-ty, and was composed of interlacing bundles of bland spindle cells without mitosis (Fig. 2C). Immunohistochemical staining showed that the tumor was strongly positive for alpha-smooth muscle actin (Fig. 2D), but negative for CD34, CD117, and S100 (data not shown). Collectively, the lesion was diagnosed as a leiomyoma with overlying squamous cell carcinoma in situ. The patient showed no evidence of recurrence for four years. DISCUSSION Squamous cell carcinomas and leiomyomas are common epi-thelial and mesenchymal tumors of the esophagus, respectively. But the coexistence of these two diseases is rare. Regarding their coexistence, however, squamous cell carcinoma and sub-mucosal leiomyoma have been reported as either the overlying type or the separated type. 1 Cases with squamous cell carcinoma overlying leiomyoma are extremely rare, and there have only been 15 cases reported, to our knowledge. All fifteen cases were male. Eight …