OTHER NEOPLASMSOTHER NEOPLASMSOF STOMACHOF STOMACH

By Dr.R.Vinoth Prabu

1

Prof Dr.S.R.Dhamotharan MS IV Surgical unitAssistants:Dr Shanthi Nirmala MSDr Celine Foustina Mary MSDr Arulraj Kumar MS

Constitutes 10%

• Lymphoma 3-4%

• Mesenchymal tumors– GIST 1-2%– leiomyosarcoma 1% others 1%

• Endocrine tumors 1%– Carcinoid - commonest

2

3

LYMPHOMA

• Stomach – MC site of primary GI Lymphoma(95% NHL)

• Sixth to seventh decades

• Most common B cell type(MALT) Next DLBCL

• H.Pylori

4

55-65%

20-35%

7-20%

What is MALT?

– Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT)

– Heterogeneous, predominantly small B-lymphocytes 5Lymphoepithelial lesions

Diagnosis

Barium study

CT scan

Endoscopy

Endoscopic ultrasound

6

7

1 2Endoscopy

Dawson’s criteria

• No palpable superficial lymphadenopathy

• No mediastinal involvement on CXR

• Normal Total & Diff. Count

• At surgery– disease limited to dominant bowel lesion and adjacent

nodes– No liver or spleen involvement

8

9

MALT

10

• RCHOP

• RT

• Both

11

DLBCL

12

GIST

• Distinct group of mesenchymal tumors recognized after

1990 with IHC

• Adults

• M>F

• Small asymptomatic GISTs are found at autopsy in more than 50 % of individuals over the age of 50

13

GISTs are identified by

either c-kit immunoreactivity (detection of the CD117 antigen) or the presence of activating mutations in kit or PDGFRA

cell of origin – interstitial cells of cajal– c.kit proto oncogene is responsible for development of

tumor

14

Cellular Morphology

• Three relatively distinctive types

Spindle cell type – 70 percent Epithelioid type – 20 percent, more commonly c-kit negative

and found in omentum and mesentery Mixed type – 10 percent.

15

Histopathology

• Differential Diagnosis • H&E stain: Melanoma, leiomyoma/sarcoma,

peripheral nerve sheath tumor, desmoid • Histology difficult

• Immunophenotyping crucial 95 % are positive for C-kit (CD117) 60-70 % positive for CD34 • Negative for alpha-smooth muscle actin

(SMA) (leiomyoma) • Negative for S100 protein (Schwannoma) • Negative for Desmin (desmoids)

16

Determinants of Malignant Behavior Determinants of Malignant Behavior

17

Metastasis

GISTs behave differently than other soft tissue sarcomas:

• GISTs frequently metastasize to the liver and rarely to regional lymph nodes

• GISTs virtually never metastasize to lungs whereas this is the most common site of metastasis for leiomyosarcomas

18

Clinical Manifestations

• Mesenchymal tumors of the GI tract are often asymptomatic and discovered incidentally during endoscopic or barium studies.

• Overt GI bleeding — 40 percent • Abdominal mass — 40 percent • Abdominal pain — 20 percent

• The vast majority of GIST metastases at presentation are intra-abdominal, either with metastases to the liver, omentum, or peritoneal cavity .

19

Investigations

20

CT Scan

EndoscopySpecimen

21

EUS

Imatinib (Gleevec) a Tyrosine Kinase Inhibitor

• Imatinib mesylate is a protein-tyrosine kinase inhibitor that inhibits the Bcr-Abl tyrosine kinase.

• Thyrosine kinase inhibtor effective in metastatic and unresectable disease.

• Shows > 50% regression.

• Duration of therapy not yet known. 22

23

Management

24

Progressive disease

25

TUMOR ARISING FROM LESSER CURVATURE STOMACHTUMOR ARISING FROM LESSER CURVATURE STOMACHAND GROWING INTO LESSER OMENTUMAND GROWING INTO LESSER OMENTUM

26

TUMOR ISOLATED AND FREE MARGIN AFTER EXCISIONTUMOR ISOLATED AND FREE MARGIN AFTER EXCISION

27

28

CARCINOID

• Composed of argyrophlic ECL cells

• 8% of all GI Carcinoids

• Pernicious anemia and atropic gastritis

• 5% will produce carcinoid syndromes

• Carcinoid tumors of stomach produce atypical symptoms or asymptomatic

29

30

Endoscopy

31

32

Endoscopic Ultrasound

33

34

35

?

THANKTHANK YOU YOU

36