Gastrointestinal stromal tumor presenting as a rectovaginal mass. Clinicopathologic and molecular-genetic characterization of a rare tumor with a literature review.
Rectal gastrointestinal stromal tumors are rare. To date, 12 gastrointestinal stromal tumors have been reported as pelvic vaginal masses. We describe a rectovaginal tumor in a 39-year-old woman. The tumor frequently recurred after multiple surgical excisions and interrupted imatinib treatment without metastasizing. Magnetic resonance tomography demonstrated a partial response under imatinib. The patient was alive with stable disease under imatinib 44 months from initial diagnosis. Molecular analysis showed a somatic 6-base pair deletion in exon 11 of c-KIT (W557_K558del) in both the primary tumor and the third recurrence; the recurrence had an additional exon 17 mutation (N822K). Comparative genomic hybridization analysis of the primary tumor showed loss of 14q and gain of 1q. Recurrence showed complete loss of nuclear p16 expression. Molecular studies and p16 status confirmed the typical characteristics of gastrointestinal stromal tumors with an aggressive phenotype underscoring the need for a special interdisciplinary treatment and for achieving complete local excision with free margins.
Department of Human Genetics, University of Magdeburg, 39112 Magdeburg, Germany.
Antje-Friederike
AF
Pelz
Abbas
A
Agaimy
Marc
M
Daniels
Matthias
M
Evert
Hans-Ulrich
HU
Schulz
Petra
P
Lüders
Gudrun
G
Müller
Jerzy
J
Lasota
Albrecht
A
Röpke
Peter
P
Wieacker
Markku
M
Miettinen
Regine
R
Schneider-Stock
D000328:Adult; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001483:Base Sequence; D001549:Benzamides; D055028:Comparative Genomic Hybridization; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000235:genetics* / Q000473:pathology* / Q000628:therapy; D006801:Humans; D000068877:Imatinib Mesylate; D007150:Immunohistochemistry; D008967:Molecular Biology; D008969:Molecular Sequence Data; D009154:Mutation; D009364:Neoplasm Recurrence, Local / Q000235:genetics / Q000473:pathology / Q000628:therapy; D010879:Piperazines / Q000627:therapeutic use; D016133:Polymerase Chain Reaction; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics; D011743:Pyrimidines / Q000627:therapeutic use; D012004:Rectal Neoplasms / Q000235:genetics* / Q000473:pathology* / Q000628:therapy; D014625:Vaginal Neoplasms / Q000235:genetics* / Q000473:pathology* / Q000628:therapy
D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate; D019009:Proto-Oncogene Proteins c-kit