[Clinicopathological features of differentiated-type dysplasia of the esophagus]

Objective: To investigate the clinicopathological features of differentiated-type (squamous) dysplasia of the esophagus. Methods: A total of 184 cases of esophageal differentiated-type dysplasia were collected retrospectively at People's Liberation Army Joint Logistics Support Force 989 Hospital (formerly 152 Hospital), and Beijing Chaoyang Hospital, Capital Medical University, China from 2016 to 2019. Their histological characteristics and immunophenotypes were analyzed, and related literature was reviewed. Results: The median age of the 184 patients was 65 years (range 39-83 years), while the ratio of men to women was 1.7∶1.0. There were 17 cases in the upper esophagus, 143 in the middle esophagus and 24 in the lower esophagus. The median diameter of the dysplasia was 15 mm (range 2-50 mm). According to the Paris classification, 2 cases were 0-Ⅰ, 25 cases were 0-Ⅱa, 70 cases were 0-Ⅱb, 74 cases were 0-Ⅱb and 0-Ⅱc and 13 cases were 0-Ⅱc. Macroscopically, the lesional mucosa was reddish with rough surface and white moss; capillary abnormality was found on narrow-band imaging. Histologically, dysplastic cells had distinct features of squamous epithelium, with abundant eosinophilic cytoplasm, round to irregular nuclei, coarse chromatin, obvious nucleolus, and conspicuous mitoses. The cellularity was increased, the arrangement of cells was disordered, and the polarity of cells in basal layer was lost. When the dysplasia did not completely spread to the whole layer of squamous epithelium, a clear boundary was often formed between the dysplasia and the normal epithelium above it. The neoplastic epithelial protrusions often grew toward the lamina propria and were accompanied by conspicuous inflammatory cell reaction at its frontal edge. Sometimes, abnormal mature single epithelial cells or cell clusters infiltrated into the lamina propria. There were high-grade dysplasia of the common type and superficial invasive squamous cell carcinoma in 98 cases of differentiated-type dysplasia. Immunohistochemical staining showed that the mutation rate of TP53 was 47.7% (53/111). The median of Ki-67 labeling index was 50.0% (range 10%-80%), while that of basal tumor cells was 12/HPF (range 3-65/HPF). The abnormal distribution pattern of Ki-67 was seen in 111 (100%) cases. According to the initial pathological diagnosis, there were 16 cases of low-grade intraepithelial neoplasia, 37 cases of atypical epithelial cells and 131 cases of high-grade intraepithelial neoplasia and superficial invasive squamous cell carcinoma. Conclusions: The morphology of differentiated-type dysplasia of the esophagus is unique. Characteristics of highly differentiated dysplastic cells suggest that they may represent a differentiated type in the morphological lineage of esophageal squamous (high-grade) dysplasia. When the knowledge of the lesion is insufficient, it is easy to be misdiagnosed or missed in pathologic examination.