Case of the month

1
Case of the month

• Dr Thanikachalam Pasupati
• IMU

2

• A 56-year-old female presented with loss of
  appetite, easy fatigability and upper abdominal
  fullness.
• There was no apparent loss of weight.
• Non-smoker, but consumed wine regularly over
  weekends.

3

• On examination, there were no palpable masses in
  the abdomen.
• There was no guarding or rebound tenderness.
• Liver and spleen were within normal limits.

4

• Haemogram
• Low PCV
• Microcytic hypochromic picture
• Normal platelet count

5

• FOBT was positive.
• Endoscopy
• A fairly large, single, polypoidal lesion in the
  stomach.
• No ulcers noted.

6

• The lesion was excised and sent to the
  pathologist for a final diagnosis.

7

• What is the differential diagnosis at this
  stage?( any three)
• Ans adenoma, leiomyoma, malignant polyp
• Will any other investigation be helpful?
• Ans Not necessarily. A CT scan to rule out any
  suspicion of malignancy with secondary deposits
  or lymph node enlargement.

8
Gross picture of the excised lesion
Shows a large polypoidal lesion with areas of
haemorrhage and a central fibrosed scar.
9
H E stain
Cytoplasmic vacuoles indenting the nuclear poles
10
H E stain
Tumour cells have a round epithelioid appearance.
Cytoplasm is clear. Cell membranes are well
defined. Mitotic figure as shown by the arrow.
11
H E stain
Epithelioid appearance of cells but they are
more pleomorphic. Cell borders well defined.
12
PAS stain
PAS stain showing skenoid fibres
13
H E stain
Prominent palisading of cells
14
Marker study CD 117
Strong positvity of CD117
15

• What is your final diagnosis?
• Ans
• This tumour is called GIST- gastrointestinal
  stromal tumour.

16
GIST

• Gastric stromal tumours( GST) or gastrointestinal
  stromal tumours (GIST) may affect any part of the
  stomach.
• Most occur in adults aged over 30 yrs.
• M F ratio is 11

17
GIST

• May be single or multiple and vary in size.
• Most tumours project into the lumen as an
  endophytic polypoidal lesion as like in this
  case.
• Lesions are prone to surface ulceration and
  bleeding( FOBT is positive in such cases)

18
GIST

• Well circumscribed but no true capsule.
• Cut surface is gray to pink with a rubbery
  consistency.
• Microscopic appearance
• Wide range of histological patterns.
• Two basic cell types- spindle and epithelioid are
  recognized.
• In the case presented both the components are
  present.
• Some show neural differentiation.

19
GIST

• Immunohistochemistry positive for vimentin, CD
  34 and c-kit (CD117).
• The pathologic assessment of malignancy in GIST
  is difficult unless invasion of adjacent
  structures is apparent or there are overt
  metastases.

20
GIST

• Further reading
• Gastrointestinal stromal tumours with prominent
  myoid matrix. Am J Surg Pathol1959-70
• Ackermans Surgical Pathology 9th edition.