Reactive nodular fibrous pseudotumor: A first report of gastric localization and clinicopathologic review
ABSTRACT Reactive nodular fibrous pseudotumor (RNFP) of the gastrointestinal tract is a distinct benign lesion, which could originate from a reactive proliferation of multipotential subserosal cells. This is the first case to be reported in the stomach. It was fortuitously discovered in a 60-year-old man with history of bulbar ulcer and gastritis. Gross examination revealed three lesions in the gastric wall and an adjacent lesion in the lesser omentum. Histologically, lesions were composed of a proliferation of spindle and stellate cells in a dense collagenic hyalinized background containing a mononuclear cell inflammatory infiltrate with numerous lymphoid aggregates and plasma cells with perivascular disposition. Immunohistochemistry showed staining for cytokeratins (AE1/AE3), vimentin and smooth muscle actin, without staining for the neurofilament and S100 proteins, synaptophysin, calretinin, CD117 (c-kit), CD34, desmin, caldesmon or anaplastic lymphoma kinase (ALK-1). Complete excision was performed, and no evidence of disease was found 4 months later. After analysing clinical, morphological and immunohistochemical features of this entity, the main differential diagnoses will be discussed, including calcifying fibrous pseudotumor, which shares morphological characteristics with RNFP, but which immunohistochemistry and the ultrastructural study suggest that it may be a result of another reactive process.
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- "These tumors generally arise in the setting of previous trauma or inflammation and, thus, represent an exuberant inflammatory response rather than a true neoplasm. Within the literature, RNFP has been associated with longstanding peptic ulcer  , pancreatitis , duodenal diverticulum , endometriosis , foreign bodies , and postoperative adhesions . In this patient, however, as well as a handful of others, the precise cause of RNFP remains unknown. "
ABSTRACT: We describe a case of a 13-year-old girl presenting with acute abdominal pain and imaging suggesting acute appendicitis. Upon laparoscopy, she was found to have a mass attached to the jejunum that had torsed upon its blood supply. On histopathologic studies, the mass was determined to be a reactive nodular fibrous pseudotumor. This lesion is a benign neoplasm that may arise from the gastrointestinal tract and has only been recently described in the literature. Our case is unique because it is the first report of reactive nodular fibrous pseudotumor presenting as a torsed polypoid lesion and the first arising in an adolescent.Journal of Pediatric Surgery 04/2012; 47(4):795-8. DOI:10.1016/j.jpedsurg.2012.01.001 · 1.39 Impact Factor
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ABSTRACT: Hyalinised fibrous nodules have been encountered within the gastrointestinal tract (GIT) and been labelled as reactive nodular fibrous tumours. Several have a history of abdominal surgery and/or sepsis that acts as a precipitating cause for the fibrosis. Recently, much attention has been focused on IgG4 related fibrosing lesions that are typically associated with a high population of IgG4 positive plasma cells and tissue fibrosis. There may be attendant elevated serum IgG4 levels and associated autoimmune disease. We present four patients with well-circumscribed fibrous nodular lesions occurring in the GIT. Tissue was formalin fixed after microwave antigen retrieval and H&E stains and immunohistochemistry were performed. IgG4/IgG ratios were calculated from the three high power fields containing the densest concentration of positive plasma cells. The patients were two females (45 and 56 years) and two males (47 and 60 years) who presented with gastric (2 cases), caecal and sigmoid flexure involvement. One case had four lesions while the other three cases were solitary nodules. Two patients had coexistent autoimmune disease. All lesions were nodular and composed of paucicellular, hyalinised fibrous tissue associated with chronic inflammation. In all lesions the plasma cell population was strongly IgG4 positive. This paper describes unique, well-circumscribed sclerosing nodules containing IgG4 positive plasma cells within the bowel wall that may cause mucosal polypoid lesions. It is possible that these lesions may be related to the spectrum of IgG4 related sclerosing disease or belong to a separate subset of inflammatory reactive conditions that are rich in IgG4 plasma cells.Pathology 01/2011; 43(1):31-5. DOI:10.1097/PAT.0b013e328340e450 · 2.19 Impact Factor
- Surgery for Obesity and Related Diseases 03/2013; 9(5). DOI:10.1016/j.soard.2013.03.003 · 4.07 Impact Factor