Comparison of morphological, immunohistochemical, and molecular genetic features of inflammatory fibroid polyps (Vanek's tumors).

Abstract

Vanek's tumor (inflammatory fibroid polyp) is a rare benign lesion occurring throughout the digestive tract. Histologically, two patterns can be recognized. Classical Vanek's tumor contains concentric formations of proliferating spindle cells which are CD34 positive. Atypical, inflammatory pseudotumor-like Vanek's 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 Vanek's 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 Vanek's 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 Vanek's 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) Vanek's tumors. The results of this study suggest that the two morphological patterns of Vanek's 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 Vanek's tumors.

• Authors: Ondrej Daum, Jana Hatlova, Vaclav Mandys, Petr Grossmann, Petr Mukensnabl, Zdenek Benes, Michal Michal
• Journal: Virchows Archiv : an international journal of pathology (Virchows Arch) Vol. 456 Issue 5 Pg. 491-7 (May 2010) ISSN: 1432-2307 [Electronic] Germany
• PMID: 20393746 (Publication Type: Journal Article)

Chemical References

• Receptor, Platelet-Derived Growth Factor alpha
• BRAF protein, human
• Proto-Oncogene Proteins B-raf

Topics

• Adult
• Aged
• Aged, 80 and over
• Exons
• Female
• Gastrointestinal Tract (pathology)
• Humans
• Intestinal Diseases (genetics, pathology)
• Leiomyoma (genetics, pathology)
• Male
• Middle Aged
• Mutation
• Polyps (genetics, pathology)
• Proto-Oncogene Proteins B-raf (genetics)
• Receptor, Platelet-Derived Growth Factor alpha (genetics)
• Stomach Diseases (genetics, pathology)