Concurrent GIST of large & small bowel: A rare case

R Gokul.k.shanker, MS, Praveen Patil, MS, Hariprasad D, MS, Vg Mohanprasad, MS, Balu Kuppusamy, MS. Vgm Hospital Institute Of Gastroenterology.

BACKGROUND:
Concurrent gastrointestinal stromal tumour(GIST) in large & small bowel is unreported in the literature.Over the last years the management of GISTs has evolved rapidly. A lot of changes have been reported in histological diagnostic criteria, in understanding of GISTs’ molecular biology and pathogenesis, in imaging strategy, in surgical and adjuvant treatment [1]. Although the outcomes of several published series helped in understanding
their pathogenesis, little is known about their coincidence with other tumors of different histogenesis. There are
some data regarding the co-occurrence, the association and the potential common origin (genetic pathways of
tumorigenesis), between GIST and other tumors [2,3]. The limited number of these cases can not confirm the
existence of a common factor in tumorigenesis of these histopathologically completely different tumors and further
studies are needed to clarify the possible association [3]. The coexistence of GISTs with other primaries is usually discovered incidentally during GI surgery for carcinomas [4].

DESIGN OBJECTIVES & PROCEDURE:

A 59 year old female was admitted with chief complaints of abdominal pain in right upper quadrant with loss of weight & appetite since 6 months.No history of gastrointestinal bleed ,back pain,jaundice.On physical examination abdomen was normal.Blood investigations revealed low haemoglobin with rest all parameters being normal.Colonoscopy showed proliferative friable growth at ascending colon with histology showing poorly differentiated adenocarcinoma(Fig.1).CT scan of abdomen & pelvis showed large intraluminal polypoidal growth 4.6×3.8 cm in ascending colon,with no local infiltration & rest of bowel loops normal(Fig.2).
Laparotomy revealed large polypoidal growth of 7×4 cm size in ascending colon with concurrent growth in small bowel of 4×3 cm size 60 cm from ileocaecal junction.Right hemicolectomy done with ileotransverse anastomosis (Fig.3).Post operatively she received imatinib therapy.

RESULTS:

Histopathological examination of resected specimen showed malignant epitheloid GIST with marked necrosis,marked pleomorphism and atypical mitoses more than 20 mitoses/10 high power field(Fig.4,5).Immunohistochemistry analysis revelead CD 117/KIT positive with brisk mitosis more than 25/10 high power field in both large & small bowel tumours(Fig 6,7).
Epitheloid GISTs are often diagnosed in an endoscopic biopsy as a poorly differentiated adenocarcinoma.

CONCLUSION:

Incidence of concurrent GIST in large & small bowel is unreported.In any case of GIST surgeon should be alert to recognise a possible co-existent tumour which secures the patient’s best prognosis.

REFERENCES:
1.Maiorana A, Fante R, Maria Casinaro A, Adriano Fano R: Synchronous occurrence of epithelial stromal tumors in the stomach: a report of 6 cases. Arch Pathol Lab Med 2000, 124:682-686.
2. Sugimura T, Fujimura S, Baba T: Tumor production in the glandular stomach and alimentary tract of the rat by N-methyl- N’-nitro-N-nitrosoguanidine. Cancer Res 1970, 30:455-465.
3. Melis M, Choi EA, Anders R, Christiansen P, Fichera A: Synchronous colorectal adenocarcinoma and gastrointestinal stromal tumor (GIST). Int J Colorectal Dis 2006, 22:109-114.
4. Agaimy A, Wunsch PH, Sobin LH, Lasota J, Miettinen CM: Occurrence of other malignancies in patients with gastrointestinal stromal tumors. Semin Diagn Pathol 2006, 23(2):120-129

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