GIST in NF1 (neurofibromatosis) (see left sidebar for detailed criteria for GIST)
Germ line NF1 mutation
Autosomal dominant
Associated with café au lait spots, neurofibromas, pheochromocytomas
0-15% with identifiable somatic CKIT or PDGFRA mutations in GIST
CKIT and DOG1 positive in 90-100%
Mean age 40-50
Males and females affected
Usually small intestine
Frequently multiple
Nearly all are spindled
Skeinoid fibers very common (80%)
Interstitial cell of Cajal hyperplasia in most cases
35-65% of GIST are S100 positive
May be patchy
Usual GIST 5% positive
Most are small and benign
May be aggressive if large and mitotically active
References (see left side bar for general GIST bibliography)
Takazawa Y, Sakurai S, Sakuma Y, Ikeda T, Yamaguchi J, Hashizume Y, Yokoyama S, Motegi A, Fukayama M. Gastrointestinal stromal tumors of neurofibromatosis type I (von Recklinghausen's disease). Am J Surg Pathol. 2005 Jun;29(6):755-63.
Andersson J, Sihto H, Meis-Kindblom JM, Joensuu H, Nupponen N, Kindblom LG. NF1-associated gastrointestinal stromal tumors have unique clinical, phenotypic, and genotypic characteristics. Am J Surg Pathol. 2005 Sep;29(9):1170-6.
Miettinen M, Fetsch JF, Sobin LH, Lasota J. Gastrointestinal stromal tumors in patients with neurofibromatosis 1: a clinicopathologic and molecular genetic study of 45 cases. Am J Surg Pathol. 2006 Jan;30(1):90-6.
Wang JH, Lasota J, Miettinen M. Succinate Dehydrogenase Subunit B (SDHB) Is Expressed in Neurofibromatosis 1-Associated Gastrointestinal Stromal Tumors (Gists): Implications for the SDHB Expression Based Classification of Gists. J Cancer. 2011 Feb 16;2:90-3.
