[Spindle cell type squamous dysplasia of the esophagus: a clinicopathological analysis].

Objective: To investigate the clinicopathological features and significance of spindle cell type squamous dysplasia of the esophagus. Methods: The clinicopathological data of 37 cases of spindle cell type squamous dysplasia of esophagus were collected retrospectively at People's Liberation Army Joint Logistics Support Force 989 Hospital (formerly 152 Hospital), Pingdingshan, China, from 2009 to 2019. The histological and immunohistochemical characteristics were analyzed, with a literature review. Results: The median age of the 37 patients was 65 years (range 47-81 years), while the ratio of men to women was 1.5∶1.0. There were 4 cases in the upper esophagus, 31 in the middle esophagus and 2 in the lower esophagus. The median diameter of the lesions was 14 mm (range 3-40 mm). According to the Paris classification, 11 cases were 0-Ⅱa, 14 cases were 0-Ⅱb, 3 cases were 0-Ⅱb and 0-Ⅱa, and 9 cases were 0-Ⅱc. Under endoscope, the lesional mucosa was reddish. The micro-vessels were dilated, with various shapes and density. Histologically, tumor cells and nuclei were spindle shaped or elongated spindle shaped, with considerable homogeneity, dark nuclei and delicate or slightly thickened chromatin. The mitosis was conspicuous, and atypic mitoses were seen; the cytoplasm was acidophilic, and the intercellular bridge was obvious. The cells were dense and often lost polarity, but still arranged in parallel, mostly perpendicular to the basement membrane. Spindle cells often involved the whole layer of epithelium, with no gradient maturation and differentiation of normal squamous epithelium. The tumor was well demarcated. The spindle cells often invaded lamina propria. There were 15 cases with focal high-grade dysplasia and superficial invasive squamous cell carcinoma. Immunohistochemical staining showed that the mutation rate of p53 was 41.4% (12/29), the median of Ki-67 labeling index was 40% (range 20%-80%), and the abnormal distribution pattern of Ki-67 was 29 (100%). According to the initial pathological diagnosis, there were 6 cases of low-grade dysplasia, 4 cases of atypical epithelial cells and 27 cases of high-grade dysplasia and superficial invasive squamous cell carcinoma. Conclusions: Spindle tumor cells have moderate to severe atypia, and some tumors show invasive pattern. P53 mutation and Ki-67 abnormal distribution pattern indicate that they are high-grade dysplasia of esophageal squamous epithelium. The unique characteristics of spindle tumor cells suggest that they may represent a spindle cell subtype in the morphological spectrum of esophageal squamous dysplasia. When the knowledge of the lesion is insufficient, it can be easily misdiagnosed or missed.