Content area
Full Text
Virchows Arch (2010) 456:491497 DOI 10.1007/s00428-010-0914-8
ORIGINAL ARTICLE
Comparison of morphological, immunohistochemical, and molecular genetic features of inflammatory fibroid polyps (Vaneks tumors)
Ondrej Daum & Jana Hatlova & Vaclav Mandys &
Petr Grossmann & Petr Mukensnabl & Zdenek Benes &
Michal Michal
Received: 19 January 2010 /Revised: 26 February 2010 /Accepted: 25 March 2010 /Published online: 15 April 2010 # Springer-Verlag 2010
Abstract Vaneks tumor (inflammatory fibroid polyp) is a rare benign lesion occurring throughout the digestive tract. Histologically, two patterns can be recognized. Classical Vaneks tumor contains concentric formations of proliferating spindle cells which are CD34 positive. Atypical, inflammatory pseudotumor-like Vaneks tumor lacks concentric formations and is CD34 negative. Recently, mutations in platelet-derived growth factor receptor alpha (PDGFRA) were reported in gastric and small intestinal Vaneks tumors. In this study, KIT exons 9, 11, 13, and 17, PDGFRA exons 12, 14, and 18, and a part of exon 15 BRAF for point mutation V600E were screened in 23 cases
of Vaneks tumor, both classical (n=16) and inflammatory pseudotumor-like (n=7). No mutations in all analyzed exons of KIT and BRAF and in exon 14 of PDGFRA were detected. Six Vaneks tumors harbored activating mutations in PDGFRA exons 12 (n=5) and 18 (n=1), respectively: S566_E571delinsK (n=1), S566_E571delinsR (n=4), and D842 del (n=1). The mutations were detected in the classical (n=5), as well as inflammatory pseudotumor-like (n=1) Vaneks tumors. The results of this study suggest that the two morphological patterns of Vaneks tumor more probably represent only variants of one type of tumor than two different lesions. Furthermore, BRAF mutations were not shown to drive growth of PDGFRA wild-type Vaneks tumors.
Keywords GIT. Inflammatory fibroid polyp . Vaneks tumor. PDGFRA . BRAF. CD34
Introduction
Vaneks tumor (inflammatory fibroid polyp, IFP) is a rare mesenchymal lesion of the gastrointestinal tract first described by Vanek in 1949 [1]. Histologically, it is distinguished as a localized proliferation of spindle, stellate, or epithelioid cells centered in the submucosa, accompanied by an inflammatory reaction predominantly composed of lymphocytes and eosinophilic granulocytes, with lymphatic vessels, capillaries, and vascular channels in the stroma having propensity for fibroproduction and edema. Most investigators considered this lesion to be of non-neoplastic, benign, and reactive origin. However, recently, mutations in platelet-derived growth factor receptor alpha (PDGFRA) were reported...