Reactive nodular fibrous pseudotumors of the gastrointestinal tract: Report of 8 cases
ABSTRACT Eight cases of reactive nodular fibrous pseudotumor of the gastrointestinal tract are presented. The patients included 6 males and 2 females between the ages of 1 and 68 years (mean age 41.5 years). Three tumors involved the small intestine, and 5 of the investigated lesions were located in the large bowel. Of these, 2 originated in the sigmoid colon, 1 in the cecum, 1 in the appendix, and 1 in the large bowel not otherwise specified. The tumors' size varied from 3 to 10 cm in the greatest diameter (mean 6.2 cm). Histologically they were composed of stellate or spindle shaped cells resembling fibroblasts arranged haphazardly or in intersecting fascicles, embedded in a collagen-rich stroma, with sparse intralesional mononuclear cells frequently arranged in lymphoid aggregates. Immunohistochemically, the lesions were positive for vimentin (7/7), smooth muscle actin (8/8), muscle-specific actin (5/7), cytokeratins AE1/AE3 (6/7), and CAM 5.2 (1/7), and antigen CD68 (1/7). No case (0/8) reacted positively with antibody to CD117 (c-kit). Genetically no substitutions, deletions, or insertions occurred in exon 11 in all analyzed samples. Likewise, no deletions or insertions in part of exon 9 were observed. Ultrastructurally the tumor cells revealed features typical of myofibroblasts. According to the morphologic, immunohistochemical, and ultrastructural features mentioned above, especially to the positivity of low-molecular-weight cytokeratins, we propose this lesion to be related to a proliferation of multipotential subserosal cells rather than ordinary myofibroblasts or fibroblasts.
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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 · 1.31 Impact Factor
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ABSTRACT: We report the rare occurrence of an inflammatory fibroid polyp of the appendix. The lesion was diagnosed in a 33-year-old woman presenting with abdominal pain, fever and localized tenderness in right iliac fossa on abdominal palpation. CT-scan showed an 8 cm appendiceal mass and a laparoscopic appendectomy was consequently performed. On microscopic examination, the tumor consisted of spindle cells dispersed in a loose fibromyxoid stroma containing numerous blood cells and inflammatory cells with abundant eosinophils. On immunohistochemistry, the spindle tumor cells were positive for vimentin, fascin and focally for CD34 and CD35. They were negative for smooth muscle actin, desmin, CD21, CD23, CD117 and S100 protein. Inflammatory fibroid polyp is a rare benign mesenchymal tumor of the gastrointestinal tract rarely reported in the appendix. This tumor shares some common pathologic features with the myofibroblatic inflammatory tumor but they are two different entities. The pathogenesis of this tumor remains unclear but fascin and CD35 immunoreactivity of the tumor cells suggests a probable dendritic cell origin.Gastroentérologie Clinique et Biologique 04/2008; 32(3):274-7. DOI:10.1016/j.gcb.2007.07.003 · 1.14 Impact Factor
Article: Tumoral, quasitumoral and pseudotumoral lesions of the superficial and somatic soft tissue: new entities and new variants of old entities recorded during the last 25 years. Part XII: Appendix Lesioni tumorali, quasitumorali e pseudotumorali delle parti molli somatiche e superficiali: entità nuove e varianti di entità già note, descritte negli ultimi 25 anni. Parte XII: Appendix