Warthin's tumor: An unknown pathogenesis: A neoplasm or a reactive hyperplasia.

Background and Aims: To examine the probable role of angiogenesis and lymphangiogenesis in the pathogenesis of Warthin's tumor. Materials and Methods: Sixty-one patients with Warthin's tumor (n = 40), branchial cysts (n = 6), thymic cysts (n = 3), or tonsillar lymphoepithelial cysts (n = 12) were included. Forty Warthin's tumors were used as the lesion group, and 21 lymphoepithelial cysts were used as a control group. 29 lymph nodes around the Warthin's tumor, four of which showed salivary duct inclusions, were also evaluated. Blood vessel density was defined as an indicator of angiogenesis by examining CD31 and FVIII Ag expression, and lymphatic vascular density was defined as an indicator of lymphangiogenesis by evaluating LYVE-1 and podoplanin expression by immunohistochemical analysis. Statistical Analysis Used: Data are expressed with descriptive statistics. Comparative analysis was performed using Shapiro-Wilks, Mann-Whitney U, and Kruskal-Wallis tests. A P < 0.005 was considered to indicate statistical significance. Statistical analysis was performed using the MedCalc ® v.10.3.0 software. Results: The lesion group had higher mean values of age (58 vs. 11 years, P = 0.001), smoking rate (92.3% vs. 19%, P < 0.001), stromal degeneration (100% vs. 42.9%, P < 0.001), lymph node involvement around the lesion (87.9% vs. 12.1%, P < 0.001), salivary duct inclusion (25% vs. 0%, P = 0.0001), than those of lymphoepithelial cysts. Blood vessel density (51.92 ± 25.64 vs. 8 ± 5.35, number/5 high power fields (HPF), P < 0.001) and lymphatic vascular density (68.95 ± 21.32 vs. 21.10 ± 4.05 number/5 HPF, P < 0.001) were higher in Warthin's tumors than lymphoepithelial cysts. Warthin's tumors, and lymph nodes with inclusions had similar levels of blood and lymphatic vascular density, which was higher than those of lymph nodes (P < 0.0001). Conclusions: Warthin's tumor is a true neoplastic epithelial proliferation associated with increased angiogenesis and lymphangiogenesis and induces reactive lymph node hyperplasia.

Neurogenous hyperplasia in the oesophagus

Leiomyoma and gastrointestinal stromal tumours take fi rst place among mesenchymal tumours of the oesophagus, where tumours of peripheral nerve origin are rarely seen. Schwann and enterochromaffi n cell proliferation occur in neurogenous hyperplasia, an entity observed in the appendix which has not been reported in the oesophagus in the medical literature. Oesophagogastroscopy of a 58-year-old woman showed linear erosions and nodularity at the gastroesophageal junction. The microscopic examination of biopsies taken from this area revealed proliferation of spindle cells with oval-round nuclei forming focal fascicular arrangement in the lamina propria. These cells stained positive for synaptophysin and S100-protein, while immunohistochemistry for smooth muscle actin and CD117 were negative. The case was diagnosed as neurogenous hyperplasia with these fi ndings. Control endoscopic biopsies showed no evidence of neurogenous hyperplasia. Neurogenous hyperplasia can be considered as a distinct entity which might also be observed in the oesophagus as in the appendix.