APCON 2008 Chennai
NATIONAL
PATHOLOGY QUIZ – 7
Answers
Q 1: Fetus in fetu
Fetus in fetu is a rare congenital anomaly in which there is unequal division of totipotential cells of a blastocyst with the inclusion of these cells into the more mature embryo. It is probably due to embryonic duplication with anomalous inclusion of one twin in the body of a host twin.
Fetus in fetu is usually differentiated from a highly differentiated fetiform teratoma (also known as 'homunculus') with well formed external structures like limbs and organs by the presence of a segmented axial skeleton. This distinction is somewhat arbitrary but is based on the hypothesis that an axial skeleton implies development past the primitive streak stage, which is thought to be unlikely in a teratoma. There are however exceptions and molecular studies are the only real way of differentiating the two. Fetus in fetu occurs usually in infancy, whereas a differentiated teratoma occurs in the ovaries of adult women.
The case presented showed a rudimentary vertebral column as shown in the figure (arrow) and because it occurred in an infant it was diagnosed as a 'Fetus in fetu'.
The diagnosis of a Fetiform teratoma will also earn full
credit.
Correct answers: 80.6%
Links
Q 2: Immunoelectrophoresis
/ Immunofixation for Alpha Heavy chain disease
A grey white fleshy mass in the wall of the small intestine. Microscopy shows an infiltrate composed of small cells infiltrating the crypts and extending below the submucosa. The cells are plasma cells, plasmacytoid lymphocytes and few lymphocytes. A lympho-plasmacytic lymphoma of the small intestine occurs most often in a setting of Alpha heavy chain disease or Immunoproliferative small intestinal disease (IPSID). This disease is also of interest for the recent demonstration of association with an infectious organism – campylobacter jejuni.
Correct answers: 55.6%
Links
1. IPSID
2. IPSID and Campylobacter jejuni
Q 3: Perineural invasion of adenocarcinoma, prostate
A fibromuscular tissue with many nerves. The perineural spaces contain dark cells. In the high power picture a small microacinus is seen in the perineural space. Diagnosis of perineural invasion is sufficient for full credit. Many of you have diagnosed it as Hirschsprung’s disease. But these are not the hypertrophied nerve bundles of Hirschsprung’s which lie between the compact circular and longitudinal smooth muscle. Besides, there is something abnormal definitely around the nerves - don’t you think?
Correct answers: 27.8%
Links
1. Significance of perineural invasion in carcinoma prostate
Q 4:
Angioimmunoblastic lymphadenopathy / lymphoma
Pictures for pattern recognition. The first two shows the arborising small vessel proliferation shown by Reticulin stain. These are mostly venules with prominent endothelial cells as shown in the third and fourth pictures which are that of a PAS stained slide. Also seen is a PAS positive eosinophilic material, mainly around the vessels.
Correct answers: 33.3%
Links
1. Angioimmunoblastic lymphadenopathy
Q 5: Hemochromatosis,
liver, Prussian blue stain
A simple one. Prussian blue staining is helpful in quantifying the iron content of liver, semi-quantitatively.
Correct answers: 83.3%
Links:
Q 6: Harald
zur Hausen
Zur Hausen is winner of this year’s Nobel Prize for Physiology and Medicine for his work on the link between cervical cancer and Human Papilloma viruses. The clues given are a gross image of cervical carcinoma and a picture of In situ hybridization for HPV in cervical carcinoma cells (from one of Zur Hausen’s papers).
Correct answers: 61.1%
Links:
1. Harald
zur Hausen and the HPV story