[Clinicopathological features of very well-differentiated adenocarcinoma of the stomach].

Objective: To investigate the clinicopathological features of very well-differentiated adenocarcinoma (VWDA) of the stomach. Methods: The clinicopathological data of 12 cases of VWDA of the stomach were collected retrospectively at the People's Liberation Army Joint Logistics Support Force 989 Hospital (formerly 152 Hospital), Pingdingshan, China, from January 2013 to May 2021. The histological characteristics and immunophenotypes were observed and analyzed with review of current literature. Results: There were 8 males and 4 females with a median age of 63 years (range 47 to 80 years). The tumor involved in the upper part of the stomach in 6 cases, the middle part in 2 cases, and the lower part in 4 cases. The median diameter of the tumors was 17 mm (range 5-65 mm). The tumor cells were similar to absorbent cells, Paneth cells, foveolar epithelial cells, and goblet cells. The cells were arranged in a single layer, and the nuclei were slightly enlarged and located at the base. The nuclei were fusiform to slightly irregular, with loss of nuclear polarity. Early tubular VWDA was found in 9 cases, and the tumor glands were similar to intestinal metaplasia. In two cases the tumors infiltrated into the submucosa. The lesions in the mucosa and submucosa showed the glands with cystic expansion, bending, branching, spiky and abortive growth pattern. One case of early papillary tubular VWDA was confined to the mucosal layer and composed of foveolar-type epithelial cells. There were two cases of advanced papillary tubular VWDA, which consisted of foveolar-type epithelial, pyloric glands, or mucinous neck cells and were associated with intra-lymphatic cancer embolus and lymph node metastases. Background mucosal atrophy and intestinal metaplasia were observed in all cases. Immunohistochemical staining showed intestinal type VWDA in 1 case, mixed gastrointestinal type VWDA in 9 cases, and gastric type VWDA in 2 cases. The Ki-67 proliferation index of 8 cases limited to the mucosa was 40%-70%, 2 cases of infiltration into the submucosa and 2 cases of advanced carcinoma was 10%-25%. All the tumors showed a wild type of p53 protein expression pattern and negative HER2. Adenocarcinoma or high-grade dysplasia was diagnosed on preoperative biopsy in 5 cases, and chronic atrophic gastritis with intestinal metaplasia in 7 cases. The median follow-up time was 28 months (range 12-72 months). No recurrence was found in the 10 patients with early cancer. Of the two patients with advanced carcinoma, one patient had lung metastases and the other died. Conclusions: Gastric VWDA is a rare low-grade malignancy with structural features of highly differentiated adenocarcinoma and extremely low cytological atypia. The diagnostic value of structural abnormality is significantly greater than cytological atypia. The invasive growth of irregular glands in the deep mucosa and submucosa is reliable evidence for diagnosis. The diagnosis of intramucosal VWDA is challenging and very difficult in some biopsy specimens.

[Clinicopathological features of basal cell type dysplasia of esophagus].

Objective: To investigate the clinicpathological features of basal cell type dysplasia of the esophagus. Methods: The clinicopathological data of 71 cases of basal cell type dysplasia of esophagus were collected at the People's Liberation Army Joint Logistics Support Force 989 Hospital, from 2009 to 2019, and the histomorphologic characteristics and immunophenotype were evaluated. The relevant literature was reviewed. Results: The ratio of male to female patients was 1.6∶1.0, and the median age was 65 years (range 48-81 years). The tumors were located in the upper segment of the esophagus in four cases (5.6%), the middle segment in 54 cases (76.1%), and the lower segment in 13 cases (18.3%).The median maximal tumor diameter was 12.0 mm (range 3-42 mm). According to Paris Classification, 0-Ⅱb accounted for 42.3% (30/71) of the cases. Under endoscope, the lesions were reddish with abnormal mucosal microvessels. Histologically, the neoplastic cells were small, with a high nuclear-cytoplasmic ratio, similar to basal cells, and uniform in morphology. The structural atypia was characterized by dense and disordered tumor cells, loss of basal cell polarity, and absence of normal squamous differentiation gradient. In 10 cases, the tumors were confined to the lower part of the epithelium. The tumor cells were smaller and more uniform in shape, and extend to the superficial lamina propria. Sixty-one tumors involved at least the entire layer of the upper cortex. There were 31 cases of neoplasms with superficial invasive carcinoma. The types of neoplasms included typical squamous cell carcinoma, basaloid squamous cell carcinoma, small cell neuroendocrine carcinoma, squamous cell carcinoma with sebaceous adenoid carcinoma, and differentiation of glandular/ductal epithelioid carcinoma. Immunohistochemical staining showed that the mutant expression rate of p53 protein was 41.5% (17/41). All 41 cases (100.0%) showed abnormal distribution pattern of Ki-67. According to the initial pathologic diagnosis, there were 18 cases of low grade dysplasia, 12 cases of atypical epithelial cells, and 41 cases of high grade dysplasia and superficially invasive carcinoma. Conclusions: Basal cell type dysplasia has unique morphologic characteristics and represents a tumor subtype in the morphologic lineage of esophageal squamous dysplasia. Tumor cells of basal cell type dysplasia, especially those distributed only in the lower part of the stratified squamous epithelium, may be tumor stem cells at the earliest stage of esophageal carcinogenesis and have multidirectional differentiation potential. When the tumor is confined to the lower part of the stratified squamous epithelium, it does not meet the diagnostic criteria for esophageal squamous dysplasia as defined by the current WHO classification.

[Clinicopathological features of basal cell layer type high-grade squamous dysplasia of the esophagus].

Objective: To investigate the clinicopathological features of basal cell layer type high-grade squamous dysplasia of the esophagus. Methods: Fifty-two cases of basal cell layer type high-grade squamous dysplasia of the esophagus were collected at PLA Joint Logistics Support Force 989 Hospital (34 cases) and Beijing Chaoyang Hospital (18 cases) from 2009 to 2019. The clinical, histological and immunohistochemical features were characterized. Related literature was also reviewed. Results: The median age of the 52 patients was 64 years (range 43-72 years). There were 35 men and 17 women, with a male to female ratio of 2.1∶1.0. There were 8 cases in the upper esophagus, 41 in the middle esophagus and 3 in the lower esophagus. According to the Paris Classification, 24 cases were 0-Ⅱb and 28 cases were 0-Ⅱc. Endoscopic examination showed that the color of the lesions was red and the edge was irregular. The narrow band imaging showed that the lesions were brown, and the microvascular abnormalities on the mucosal surface were observed with high magnification. Iodine staining of the lesions showed no or light staining and irregular border. Histologically, the basal layer of squamous epithelium was hypercellular, with large and hyperchromatic nuclei, and disordered cell arrangement. A high proportion of the cases showed a down-growth pattern and associated invasive squamous cell carcinoma. The immunohistochemical staining of 37 cases showed that the mutation rate of p53 was 48.6% (18/37), the median of Ki-67 labeling index was 60% (range 20%-90%), the median of Ki-67 labeling index of the basal tumor cells was 26/HPF (range 5-70/HPF), and the rate of abnormal Ki-67 distribution pattern was 37(100.0%). According to the initial pathological diagnosis, there were 8 cases of low-grade intraepithelial neoplasia, 2 cases of atypical epithelial cells and 42 cases of high-grade intraepithelial neoplasia. Conclusions: The basal cell layer type high-grade squamous dysplasia of the esophagus has a unique morphology. The dysplasia is mainly limited to the lower half part of the squamous epithelium. With marked cytological atypia and prominent invasiveness pattern, it is likely to develop into invasive squamous cell carcinoma at an early stage of the disease. The rate of pathologic misdiagnosis (such as low-grade lesion) is high. The p53 mutation and Ki-67 abnormal distribution pattern are helpful features for confirming the diagnosis of such high-grade dysplasia.

[Cut-off value of Ki-67 labeling index in the pathologic grading of follicular lymphoma].

Objective: To determine the cut-off values of Ki-67 labeling index (LI) in the histological grading of follicular lymphoma (FL). Methods: Clinicopathological data of 350 FL patients diagnosed at Beijing Friendship Hospital from June 2014 to January 2016 were analyzed retrospectively by quantitative evaluation and statistical analysis of Ki-67 LI. Results: Of the 350 patients with FL, the male and female ratio was 1.1 and the average age was (50.2±14.0) years with a median age of 51 years (range 4 to 82 years). The tumors were graded as grade Ⅰ-Ⅱ in 215 cases (61.4%), grade Ⅲ A in 105 cases (30.0%), and grade Ⅲ B in 30 cases (8.6%). The average Ki-67 values were (22.8%±8.3%) for the FL low (grade Ⅰ-Ⅱ) and (50.4%±10.7%) for high grade (Ⅲ A and Ⅲ B) and were statistically significant by Mann Whitney U test (P<0.01). Receiver operated characteristic curve analysis showed that the best diagnostic cut-off value of low grade FL was 35% (sensitivity of 96.3% and specificity of 93.3%) with the largest area under curve (AUC=0.990, P<0.01, 95%CI for 0.982-0.998). According to the analysis of four lattice diagnostic tests, Ki-67 LI >40% was an important factor (χ2=230.733, P<0.01) in predicting high grade FL. When the cut-off value of Ki-67 LI was set at 40%, high grade LF could be diagnosed with the greatest sensitivity (98.1%) and specificity (87.7%). Moreover, a significant correlation between the Ki-67 LI and the pathological grade of FL (r=0.836, P<0.01) was observed. Conclusions: Ki-67 LI of below a cut-off value of 35% is a reliable indicator of low grade FL.Ki-67 over 40% is consistent with high grade FL. These Ki-67 cut-off values may serveas an important auxiliary indicator in the grading of FL.