Warthin’s tumor is the second most frequent neoplasm next to pleomorphic adenoma in the salivary gland, mostly in the parotid gland. The epithelial cells constituting a tumor are characterized by the presence of mitochondria that undergo structural and functional changes, resulting in the development of oncocytes. In addition to containing epithelial cells, Warthin’s tumors contain abundant lymphocytes with lymph follicles (germinal centers) that are surrounded by epithelial cells. The pathogenesis of Warthin’s tumor is not fully understood, and several hypotheses have been proposed. The risk factors for the development of Warthin’s tumor, which predominantly occurs in males, include aging, smoking, and radiation exposure. Recently, it has been reported that chronic inflammation and aging cells promote the growth of Warthin’s tumor. Several reports regarding the origin of the tumor have suggested that (1) Warthin’s tumor is an IgG4-related disease, (2) epithelial cells that compose Warthin’s tumor accumulate mitochondria, and (3) Warthin’s tumor is a metaplastic lesion in the lymph nodes. It is possible that the pathogenesis of Warthin’s tumor includes mitochondrial metabolic abnormalities, accumulation of aged cells, chronic inflammation, and senescence-associated secretory phenotype (SASP). In this short review, we propose that DNA damage, metabolic dysfunction of mitochondria, senescent cells, SASP, human papillomavirus, and IgG4 may be involved in the development of Warthin’s tumor.

Cancer remains a major cause of cancer-related death worldwide. Over 70% of epithelial malignancies are sporadic and are related to lifestyle. Epidemiological studies suggest an inverse correlation between cancer incidence and fruit and vegetable intake. Numerous preclinical studies using in vitro (cell lines) and in vivo animal models of oncogenesis have reported the chemopreventive effects of dietary phytochemical agents through alterations in different biomarkers and signaling pathways. However, there is contrasting evidence from preclinical studies and clinical trials. To date, the most studied compounds include curcumin, resveratrol, isoflavones, green tea extract (epigallocatechin gallate), black raspberry powder (anthocyanins and ellagitannins), bilberry extract (anthocyanins), ginger extract (gingerol derivatives), and pomegranate extract (ellagitannins and ellagic acid). Overall, the clinical evidence of the preventive effects of dietary phytochemicals against cancer development is still weak, and the amount of these phytochemicals needed to exert chemopreventive effects largely exceeds the common dietary doses. Therefore, we propose a combination treatment of natural compounds that are used clinically for another purpose in order to obtain excess inhibitory efficacy via low-dose administration and discuss the possible reasons behind the gap between preclinical research and clinical trials.

Familial adenomatous polyposis (FAP) is an autosomal dominant disorder characterised by multiple colorectal adenomas caused by a germline pathological variant of APC.1 The development of colorectal cancer (CRC) has interindividual differences. Recently, colibactin-producing E. coli (pks+E. coli) has attracted attention as a factor affecting CRC development. Currently, pks+E. coli is detected in 67% of patients with sporadic CRC and in 21% of healthy individuals.2 It has been reported that pks+E. coli injects colibactin, a genetic toxin, into colonic mucosal epithelial cells, resulting in DNA damage, G2/M arrest3 and promotion of colon carcinogenesis in animal experiments.2

Microscopy can detect the presence of amoebic trophozoites in cerebrospinal fluid and tissue. The infection was confirmed in the present case by polymerase chain reaction and immunohistochemistry, but we were unable to achieve a cure. Our case rapidly progressed without any skin lesions.

Eosinophilic esophagitis (EoE), an atopic disease of the esophagus, has become increasingly recognized over the last 15 years. The epidemiology of EoE has now been reported from many countries around the world. While the clinical diagnosis of this disease depends on the patient’s clinical manifestations, the final diagnosis should be made based on the histopathological examination of esophageal mucosal biopsies. In the diagnosis of EoE, to facilitate the appropriate treatment of patients, it is extremely important to precisely recognize the presence of eosinophils in biopsy specimens of the esophageal mucosa. If eosinophils are present, EoE patients should be referred to an allergist for appropriate management with dietary modification, pharmacological agents (including corticosteroids), and/or mechanical dilation of the esophagus. We herein present and recommend the use of direct fast scarlet staining for the easy and precise recognition of eosinophils in biopsy specimens of the esophageal mucosa, a technique that has been routinely used in our laboratory.