Gastric dysplastic lesions in Helicobacter pylori-naïve stomach: Foveolar-type adenoma and intestinal-type dysplasia.

Reports of Helicobacter pylori (Hp)-naïve gastric neoplasm (HpNGN) cases have been rapidly increasing due to the recent increase in the Hp-naïve population in Japan. Most HpNGNs exhibit the gastric immunophenotype and a low malignant potential regardless of histological type. Especially, foveolar-type gastric adenoma (FGA) and intestinal-type gastric dysplasia (IGD) rarely progress to invasive carcinoma. FGA is a foveolar epithelial neoplasm that occurs in the fundic gland (oxyntic gland) mucosa and is classified as the flat type or raspberry type (FGA-RA). The flat type is a large, whitish flatly elevated lesion while FGA-RA is a small reddish polyp. Genomically, the flat type is characterized by APC and KRAS gene mutations and FGA-RA by a common single nucleotide variant in the KLF4 gene. This KLF4 single-nucleotide variant reportedly induces gastric foveolar epithelial tumorigenesis and activates both cell proliferation and apoptosis, leading to its slow-growing nature. IGD consists of an intestinalized epithelial dysplasia that develops in the pyloric gland mucosa, characterized as a superficial depressed lesion surrounded by raised mucosa showing a gastritis-like appearance. Immunohistochemically, it exhibits an intestinal or gastrointestinal phenotype and, frequently, p53 overexpression. Thus, IGD shows unique characteristics in HpNGNs and a potential multistep tumorigenic process.

Multiple Ulcers in the Ileum and Lymphadenopathy Following the Usage of Methotrexate in a Patient With Rheumatoid Arthritis: A Case Report.

This case report aims to highlight a rare occurrence of severe anemia and lymphadenopathy secondary to methotrexate (MTX)-induced ileal mucosa damage in a patient with elderly onset rheumatoid arthritis (EORA). We present the case of a 72-year-old female with a history of EORA, treated with MTX, who exhibited hematochezia without accompanying pain, diarrhea, or known infectious contacts. Diagnostic investigations included imaging and endoscopic procedures. The patient's presentation of severe anemia was atypical, given the absence of significant pain or discomfort associated with EORA. The lack of active bleeding observed during endoscopy, coupled with multiple ileal ulcers, suggested a chronic progression of mucosal damage. Laboratory findings, including normal lactate dehydrogenase, soluble interleukin-2 receptor levels, and the absence of malignancy in mucosal biopsies, ruled out MTX-induced lymphoma. The patient's condition improved with the cessation of MTX and the introduction of symptomatic treatment and anemia management. This case underscores the need for vigilant monitoring and comprehensive evaluation in patients with RA, especially the elderly, treated with MTX. It also highlights the importance of considering drug-induced complications in the differential diagnosis of anemia. The case demonstrates the necessity of a personalized approach to treatment, emphasizing regular follow-ups and adjustments based on the patient's response to therapy. This report contributes to the growing body of evidence on the complexities of managing RA in the elderly, particularly regarding the side effects of common medications like MTX.