"Stomach mass" as the first manifestation of IgG4-related disease: a case report.

BACKGROUND: IgG4-related disease mainly manifests as organomegaly and is accompanied by tissue fibrosis (Mimori, Mod Rheumatol 29(2):213, 2019) which is frequently confused with tumour (Dawei et al., J Gastroenterol Hepatol 29(12):1375-8, 2020). There are few reports with of IgG4-related disease with the first clinical manifestation involving the stomach. CASE PRESENTATION: We present the case of 46-year-old male patient with a "stomach tumour" as the first manifestation of IgG4-related disease. Gastroscopy showed a mass in the stomach, however, the pathology result was chronic inflammation with IgG4 positivity. CT scans of abdomen showed that the stomach wall was thick, the head of the pancreas was swollen, and retroperitoneal fibrosis was severe.The serum IgG4 level was 75 g/L (normal range 0.03-2.01 g/L).After treatment with methylprednisolone for one month, the symptoms were greatly relieved. CONCLUSIONS: To reduce the suffering of patients and relieve their financial burden, we should consider the possibility of IgG4-related disease when the initial manifestation is a stomach mass.

Patient-Derived Orthotopic Xenograft models in gastric cancer: a systematic review.

Patient-Derived Xenografts (PDXs) are, so far, the best preclinical model to validate targets and predictors of response to therapy. While subcutaneous implantation very rarely allows metastatic dissemination, orthotopic implantation (Patient-Derived Orthotopic Xenograft-PDOX) increases metastatic capability. Using a modified tool to analyze model validity, we performed a systematic review of Embase, PubMed, and Web of Science up to December 2018 to identify all original publications describing gastric cancer (GC) PDOXs. We identified ten studies of PDOX model validation from January 1981 to December 2018 that fulfilled the inclusion and exclusion criteria. Most models (70%) were derived from human GC cell lines rather than tissue fragments. In 90% of studies, the implantation was performed in the subserosal layer. Tumour engraftment rate ranged from 0 to 100%, despite the technique. Metastases were observed in 40% of PDOX models implanted into the subserosal layer, employing either cell suspension or cell line-derived tumour fragments. According to our modified model validity tool, half of the studies were defined as unclear because one or more validation criteria were not reported. Available GC PDOX models are not adequate according to our model validity tool. There is no demonstration that the submucosal site is more effective than the subserosal layer, and that tissue fragments are better than cell suspensions for successful engraftment and metastatic spread. Further studies should strictly employ model validity tools and large samples with orthotopic implant sites mirroring as much as possible the donor tumour characteristics.

Plexiform Angiomyxoid Myofibroblastic Tumor (PAMT) of Stomach with Synchronous Bilateral Cystic Ovarian Neoplasms, a Rare Case Presentation.

Plexiform Angiomyxoid Myofibroblastic Tumor (PAMT) is a recently identified mesenchymal tumor of the stomach, which was first described in the year 2007 and was added in the 2010 WHO classification of tumors of the digestive system World J Gastroenterol 16(6): 2835-2840, 2010. It closely resembles with other gastric tumors but distinctly varies in clinical management as well as the histopathology. We had a 51 year, female patient, laborer by profession with low socio economic status, who had abdominal pain with vomiting since 6 months. She had similar complaints 3 years ago for which she was evaluated and presumed to have Carcinoma Stomach and underwent laparotomy which ended up only with Gastro- Jejunal anastomosis. She was admitted at our institution. Endoscopy revealed antral bulge with central area ulceration and biopsy was taken which was not confirmatory for malignancy. CT images showed heterogeneous mass with necrotic changes arising from the duodenum favored the diagnosis of perigastric neoplasm. PET CT was done, 8.4 × 5 × 6.1 cm exophytic mass in the pyloric region of stomach with solid and cystic components causing significant gastric outlet obstruction. She underwent exploratory laparotomy and complete excision of mass with achievement of R0 clearance. Histopathology was reported as Plexiform angiomyxoid myofibroblastic tumor (PAMT).