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OJHAS Vol. 9, Issue 3:
(Jul - Sep, 2010) |
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| Role of RBC labeled 99m-Tc scan, Histopathology and Immunohistochemistry
in Diagnosis of Jejunal Gastrointestinal Stromal Tumor presenting as
obscure gastrointestinal haemorrhage |
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Prasad K Shetty, Department
of Pathology, Bhagwan Mahaveer Jain Hospital, Bangalore, India,
Sameer V Baliga, Department
of Surgical Gastroentrology, Bhagwan Mahaveer Jain Hospital, Bangalore,
India,
Balaiah K, Department of Pathology,
Bhagwan Mahaveer Jain Hospital, Bangalore, India,
Gnana Prakash S, Department of
Radiology, Bhagwan Mahaveer Jain Hospital, Bangalore, India. |
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Address For Correspondence |
Surgical Pathologist,
Bhagwan Mahaveer Jain
Hospital,
Vasanth Nagar, Millers Road,
Bangalore
- 560052, India.
E-mail:
dr.pkshetty@gmail.com |
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Shetty PK, Baliga SV, Balaiah K, Gnana Prakash S. Role of RBC labeled 99m-Tc scan, Histopathology and Immunohistochemistry
in Diagnosis of Jejunal Gastrointestinal Stromal Tumor presenting as
obscure gastrointestinal haemorrhage. Online J Health Allied Scs.
2010;9(3):21 |
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Submitted: Aug 21, 2010;
Accepted:
Sep 22, 2010; Published: Oct 15, 2010 |
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| Abstract: |
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Gastrointestinal stromal tumors (GIST) are relatively rare tumors of
gastrointestinal (GI) tract, most commonly arise from the stomach followed
by small intestine and colon, clinically GIST present with occult GI
bleeding, abdominal pain and intestinal obstruction. We present a case
of a jejunal GIST, which presented as an obscure GI haemorrhage. This
case highlights how oesophagogastrodudenectomy and colonoscopy proved
inconclusive in determining source of bleeding and the importance of
RBC labeled 99m-Tc scan in detecting the source of GI bleeding
and also emphasizes on histopathology and immunohistochemistry in diagnosis
of GIST.
Key Words: Gastrointestinal
stromal tumor; RBC labeled 99m-Tc scan; Immunohistochemistry
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A
75 years old male presented to surgical gastroentrology department with
3- 4 days history of passing black colored stools, no history of abdominal
pain/vomiting/hematemesis. He had no significant previous medical history.
Clinical examination reveled pallor and his blood test showed a hemoglobin
level of 7.3g/dl, his peripheral smear showed microcytic hypochromic
anemia consistent with iron deficiency. Hemospot test (standard guaiac
method) for stool reveled positive for occult blood. An oesophagogastroduodenoscopy
was done and showed mild gastritis, colonoscopy was done upto distal
10 cms of ileum revealed stools mixed with dark-red blood suggestive
of small bowel bleed. Since the GI bleeding was obscure patient was
asked to under go RBC labeled 99m-Tc scan and multiple images were taken
over a period of 5 hours which reveled accumulation of labeled RBC’s
in the small bowel at 1.5 hours and passing along large intestine in
subsequent images, which suggested slow active Gastrointestinal (GI)
bleed form small bowel probably from Jejunum.(Figure1)
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Figure1: RBC labeled
99m-Tc scan with multiple images taken over a period of 5 hours,
images taken at 1.5hours and later show Tc labeled RBC’s in the small
bowel. |
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Figure 2: Gross Photo of segment
of jejunum with a well-circumscribed gray white, lobulated tumor in the jejunal wall. |
Based
on the RBC labelled 99m-Tc scan findings an emergency laprotomy was
performed which reveled a hard, eccentric and nodular tumor in the antimesentric
border of the jejunum approximately 4 feet distal to the duodeno-jejunal
flexure . This part of the small bowel was kinked. This segment of the
jejunum was resected with the tumor with end to end anastomosis. Rest
of the small and large bowel were unremarkable.
Grossly
jejunal segment measured 11cms, out surface antimesentric border showed
a bossulated mass 4cms from one resected margin, on cut opening jejunum
lumen showed blood colts, mucosal surface covering the tumor showed
irregularities, however no frank ulceration was seen on gross examination.
On sectioning, jejunal wall showed a well-circumscribed gray white,
smooth, lobulated tumor measuring 3.5x3.5cms with whorled-appearance.(Figure 2)
Microscopy: Jejunal mucosa showed erosion, submucosa shows tumor extending up to
serosa with pushing borders, tumor showed fascicles of spindle cells
with bipolar nucleus and eosinophilic cytoplasm with 3 mitosis/50 hpf,
there was no evidence of necrosis and resected margins were free of
tumor.(Figure 3)
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Figure3: Jejunal wall with tumor showing fascicles of spindle
cells with bipolar nucleus and eosinophilic cytoplasm. (Hematoxylin
and eosin x10). |
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Figure 4: Tumor cells showing immunopositivity for CD-117 (IHC,
x 200). |
On Immunohistochemistry tumor
cells showed wide spread positively for CD117 and negative for S100
protein.(Figure 4)
Based
on Histological and immunohistochemical features we made a diagnosis
of Gastrointestinal stromal tumor (GIST) smooth muscle type benign.
Patient
had uneventful recovery.
GI bleeding is most commonly caused by polyps, inflammatory bowel disease,
infectious diarrhoea vascular anomalies and malignancies. 95% of these
disorders are usually be diagnosed by standard upper GI endoscopy and
colonoscopy. 5% of GI haemorrhage is obscure in nature and small bowel
GISTs have been described as one of the commonest cause.1-3
It has an incidence of 15 per million and forms 0.1-3% of all GI tumors,
more commonly occur in middle-aged and older people with approximately
equal sex distribution and have an overall 5-year survival of about
35%.4 GISTs predominantly occur in stomach followed by
the small intestine, colon, rectum, and oesophagus.1 Clinically
presents as GI bleeding (50%), followed by abdominal pain (20–50%) and
intestinal obstruction (20%).5
In
cases of obscure GI bleeding one must be able to image the small bowel
effectively to establish the source of bleeding. Investegations like
video capsule endoscopy (VCE) and double balloon enteroscopy (DBE) contrast-enhanced
computed tomography (CT), CT angiography and RBC labeled 99m-Tc scan
are of diagnostic importance for determining source of bleeding.6
GIST
were thought to originate form smooth muscle and were designated as
leiomyomas and leiomyosarcomas. In 1983 Maxur and Clark coined
the term gastrointestinal stormal tumor to which includes benign and
malignant mesenchymal tumors of gastrointestinal tract with myogenic
or neural phenotype based on electron microscopy and immunohistochemical
study.7
GIST
cells closely resemble the interstitial cells of Cajal which arise from
precursor mesenchymal cells, and express the transmembrane tyrosine
kinase receptor. Gene mutations in these cells result in overexpression,
causing neoplastic transformation and development of gastrointestinal
stromal tumors. This may be detected by immunohistochemistry using the
antibody CD117.8,9
GIST
are divided into four major categories on the basis of their phenotypical
features:
Category
I: GIST showing morphological differentiation towards smooth muscle cells/epitheloid
cells, as evidenced immunohistochemically by the expression of actin
and desmin. These tumors constitute by far the largest category.
Category I is further classified into three groups: (1) benign: mitotic
count less than 5 / 50 HPF, tumor size 5 cm or less; (2) borderline,
same mitotic number but tumor size larger than 5 cm; (3) malignant:
mitotic count greater than 5 / 50 HPF, any size tumor. Category
II: GIST Neural type (Malignant) showing apparent differentiation toward
neural elements, and the tumors are designated as gastrointestinal autonomic
nerve tumors (GANs), immunohistochemically positive for S-100 protein
constitute the second largest group. Category III: GIST (Potentially
malignant) showing dual differentiation toward smooth muscle and neural
elements. Category
IV: (Potentially malignant) Tumors lacking differentiation toward either
cell type. In presented case histoimmunochemical features were of GIST
smooth muscle benign.10-12
In
conclusion, RBC labeled 99m-Tc scan is one of the most important investigation
in locating the source of bleeding and Immunohistological markers CD117
and S100 in Diagnosis of GIST.
- Miettinen M, Lasota J. Gastrointestinal
stromal tumours-definition, clinical, histological, immunohistochemical,
and molecular genetic features and differential diagnosis. Virchows
Arch 2001 Jan;438(1):1-12.
- Spiller RC, Parkins RA. Recurrent
gastrointestinal bleeding of obscure origin: report of 17 cases and
a guide to logical management. Br J Surg 1983 Aug;70(8):489-493.
- Fox VL. Gastrointestinal
bleeding in infancy and childhood. Gastroenterol Clin North Am 2000;29:37–66.
- Suster S. Gastrointestinal stromal tumors: Radiologic Features with Pathologic Correlation.
Semin
Diagn Pathol 1996;13:297-313.
- Mucciarini C, Rossi G,
Bertolini F, Valli R, Cirilli C, Rashid I et al. Incidence and clinicopathologic
features of gastrointestinal stromal tumours. A population-based study.
BMC Cancer 2007;7:230.
- Hadithi M, Heine GD, Jacobs
MA, Van Bodegraven AA, Mulder CJ. A prospective study comparing video
capsule endoscopy with double balloon enteroscopy in patients with obscure gastrointestinal bleeding.
Am J Gatroenterol 2006;101:52–57.
- Connolly EM, Gaffney E, Reynolds
JV. Gastrointestinal stromal tumors. Br. J Surg 2003;90:1178- 1186.
- Graadt van Roggen JF, van
Velthuysen MLF Hogendoorn PC. The histopathological differential diagnosis
of gastrointestinal stromal tumors. J Clin Pathol 2001;54:96- 102.
- Sircar K, Hewlett BR, Huizinga
JD, Chorneyko K, Berezin I, Riddel RH. Interstitial cells of Cajal as
precursors of gastrointestinal stromal tumors. AM J Surg Pathol 1999;23:377-
389.
- Amin MB, Ma CK, Linden MD,
Kubus JJ, Zarbo RJ. Prognostic value of proliferating cell nuclear antigen
index in gastric stromal tumors. Correlation with mitotic count and
clinical outcome. Am J Clin Pathol 1993;100:428-32.
- Suster S, Sorace D, Moran
CA. Gastrointestinal stromal tumors with prominent myxoid matrix. Clinicopathologic,
immunohistochemical, and ultrastructural study of nine cases of a distinctive
morphologic variant of myogenic stromal tumor. Am J Surg Pathol 1995;19:59-70.
- Saul SH, Rast ML, Brooks
JJ. The immunohistochemistry of gastrointestinal stromal tumors. Evidence
supporting an origin from smooth muscle. Am J Surg Pathol 1987;11:464-473.
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