title: Complete Resolution of Pseudomalignant Erosion in a Reflux Gastroesophageal Polyp with Proton Pump Inhibitor.
abstract: Pseudomalignant erosion is a diagnostic pitfall for pathologists in the differential diagnosis of malignant neoplasms. Here, we present a challenging case of a biopsy specimen from the eroded head of a polyp at the esophagogastric junction. A malignant neoplasm could not be ruled out due to the presence of bizarre stromal cells. A second biopsy performed after the administration of a proton pump inhibitor (PPI) for 4 weeks revealed endoscopic resolution of the polyp along with the complete histological resolution of the bizarre stromal cells and led to the diagnosis of pseudomalignant erosion in a reflux gastroesophageal polyp. In conclusion, histological and endoscopic response to PPI therapy is an important clue for the correct diagnosis of reflux gastroesophageal polyps with pseudomalignant erosion.
authors.affiliation: Department of Diagnostic Pathology, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Takahiko
authors.initials: T
authors.lastname: Nakajima
authors.affiliation: Department of Surgery, Kouseiren Namerikawa Hospital, 119 Tokiwa-cho, Namerikawa 936-8585, Japan.
authors.forename: Haruo
authors.initials: H
authors.lastname: Yagi
authors.affiliation: Department of Diagnostic Pathology, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Hayato
authors.initials: H
authors.lastname: Baba
authors.affiliation: Department of Diagnostic Pathology, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Minamisaka
authors.affiliation: Department of Diagnostic Pathology, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Shigeharu
authors.initials: S
authors.lastname: Miwa
authors.affiliation: Department of Diagnostic Pathology, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Hayashi
authors.affiliation: Department of Diagnostic Pathology, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nishida
authors.affiliation: Department of Diagnostic Pathology, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Hatta
authors.affiliation: Department of Diagnostic Pathology, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan ; Department of Molecular and Environmental Pathology, Institute of Health Biosciences, University of Tokushima Graduate School, 3-8-15 Kuramotomachi, Tokushima 770-8503, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Tsuneyama
authors.affiliation: Department of Diagnostic Pathology, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Johji
authors.initials: J
authors.lastname: Imura