APCON 2009 Kolkata
NATIONAL
PATHOLOGY
Answers
Q 10: Fluorescent
in situ hybridization (FISH) of the human karyotype probed for Alu sequences
indicating gene rich areas
What you see in the picture is the typical human female karyotype. There are bright green fluorescent areas of varying lengths in all the chromosomes. The background is obviously a red counterstain.
Look at the pattern. Largest green areas are seen on chromosome 19. This is the most gene rich chromosome. This is followed by chromosomes 16 and 17. Chromosomes 13, 18 and 21 are the least stained and incidentally they are the most gene-poor of all the chromosomes. If you had ever wondered why it is in trisomies of these chromosomes (Edward, Patau, Down) but not in others, that the fetus survives to birth and beyond, this is the reason.
Isn’t it wonderful how molecular biology is able to answer these long pending questions?
Here the probe used
is one against Alu sequences. They are a sort of proxy for the gene rich areas
of the genome because they tend to cluster in such areas.
Alu sequences probably originated from duplication of a 7SL
RNA gene which is a part of the signal recognition particle (
They are retrotransposons which constitute 10% of the human genome. They are particularly associated with segmental duplications and may have played an important part in human evolution.
Breast cancer,
Correct answers: 11.5%
Links
- Alu repeat analysis in the human genome
- Whole genome analysis of alu and evolution
- The Genomic Trade in Spare Parts
Q 11: Hydatid cyst
The easy one. Cyst with rough shaggy interior and a soft material that resembles the kernel of tender coconut. It is a bit off-white rather than pure white. But it does indeed resemble the tender coconut. Take my word for it. I am from Kerala – the land of coconuts.
Correct answers: 69.2%
Links
1. Hydatid Disease: Radiologic and Pathologic Features
Q 12: Nesidioblastosis / Diffuse islet cell
hyperplasia
This section is from a 45 year old man who had episodes of hypoglycemia and hyperinsulinemia. No definite tumor was found in the pancreas on imaging studies and at surgery. The surgeon removed 90% of the pancreas. The blood sugar and insulin levels became normal after surgery.
The islets of Langerhans were somewhat larger than normal. More characteristically, islet cells and groups of cells were seen budding from the ducts – the so called ductulo-insular complexes. This is well seen in the Chromogranin stained slides shown in the picture. There were also small nests and individual chromogranin positive cells scattered between islets.
Islet cell hyperplasia has been defined as an increase in number of normal sized or larger islets indicating increased pancreatic islet cell mass and nesidioblastosis as a hyperfunctional disorder with small clusters of islet cells scattered without connection to the main islets as well as hypertrophic beta cells within enlarged or normal appearing islets. Ductulo-insular complexes are said to be characteristic of the latter.
Personally, I find
this distinction arbitrary and unnecessary hair-splitting.
Noninsulinoma
Pancreatogenous Hypoglycemia can have multiple causes. In infants it may be
caused by specific mutations. In adults the commonest cause seems to be gastric
bye-pass surgery. It has also been observed in rare cases of adults with
hyperinsulinemic hypoglycemia, in pancreatic tissue resected from hypoglycemic
patients who had concomitant insulinoma or had previously been treated with
insulin or a sulfonylurea, and in other clinical syndromes, such as Werner
Morrison, Zollinger-Ellison, and multiple endocrine neoplasia type 1.
Correct answers: 30.8%
Links
1. Noninsulinoma Pancreatogenous Hypoglycemia
2. Nesidioblastosis after Gastric-Bypass Surgery
3. Islet cell hyperplasia in adults
Q 13: Cystic hygroma and Fetal hydrops:
Most common cause – Turner syndrome
Fetus with a swelling at the back of the neck and generalized edema, best appreciated on the feet. Histology of the neck swelling was lymphangioma.
The combination of cystic hygroma in the neck and generalized edema (hydrops) is very suggestive of a chromosomal abnormality, the most common being Turner syndrome followed by autosomal trisomies. The autosomal trisomies are likely to be associated with other features like low set ears, Rocker-bottom feet etc. which seem to be absent in this case. No, it is not Rocker-bottom feet that you see in this case as someone has suggested, but merely edema. The former is a bony deformity characterized by a vertical talus.
All in all, Turner syndrome seems the most likely cause. Those suggesting trisomies also get full credit.
Correct answers: 37.5%
Links
1. Cystic hygroma and hydrops - Pubmed abstracts
Q 14: Metastasis from transitional cell carcinoma
Shown in the images given to you are the characteristic and supposedly diagnostic ‘cercariform cells’. Cercariform cells are described as single tumor cells with nucleated globular bodies and unipolar cytoplasmic processes with a nontapering, flattened, or bulbous or fish tail-like end. Their name is derived from the resemblance to the cercariae or larval form of certain trematode worms like schistosoma. Here are some pictures of these cercariae.
Cercariform cells if seen in large numbers are very typical of metastatic transitional cell carcinoma. Smaller numbers may be seen in other poorly differentiated malignant epithelial neoplasms.
Some have diagnosed this as squamous cell carcinoma. Tadpole cells of squamous cell carcinoma may resemble these cells. But note the total absence of keratinized cells and cells with dark pyknotic nuclei. I don’t think the tennis racket and other cells of embryonal rhabdomyosarcoma would be a serious differential diagnosis. They are much too smaller.
Correct answers: 28.8%
Links:
Q 15: Rhinosporidium seeberi – Gomori’s Methanamine Silver
Section of a large spherical sporangium bearing spores, each of which contains round black spherical bodies. The black staining and green background suggests a silver stain.
This is the sporangium of Rhinosporidium seeberi containing the so called ‘mature endospores’. The striking feature of the fully mature endospore is the presence of spherules numbering about 8 to 16. They have been designated as ‘Electron dense bodies (EDB)’ due to their electron microscopic appearance. They stain lightly with H&E and are lightly positive with PAS. They are sharply delineated and stain strikingly black with Gomori’s methenamine silver.
The resemblance of these endospores to the morular form of prototheca is great; but prototheca do not reside within such huge sporangia.
Correct answers: 30.8%
Links:
1. Rhinosporidium seeberi - review
Q 16: Herpes viral vesicle
Fully intraepidermal vesicle. There is acantholysis. If you strain your eyes a bit, you would see that many epidermal nuclei have a ground glass appearance. Don’t believe? Here is a higher power picture.
This appearance is typical of a Herpes viral blister. Could be simplex or zoster.
Correct answers: 50%
Links:
Q 17: Papillary urothelial carcinoma,
bladder with granulomatous reaction possibly due to intravesical BCG
The video begins with the normal mucosa and muscle of the bladder and moves on to the abnormal area. There is a papillary tumor located superficially and the cytological features leave no doubt that it is a carcinoma. The tumor infiltrates the subepithelial connective tissue but not the muscle. So it is a non muscle-invasive papillary urothelial carcinoma.
The tumor interior as well as the tumor bed shows marked inflammation. There are distinct epithelioid granulomas with giant cells and caseation in the tumor bed.
Is this a papillary urothelial tumor with co-existing tuberculosis or fungal infection? Or are we seeing a granulomatous inflammatory response to the tumor?
Note that the granulomas are seen precisely beneath the tumor and not in the adjacent tissue; a definite point in favor of the latter possibility.
The patient gives history of intravesical treatment done after diagnostic biopsy – presumably BCG (This was a consultation slide and old records were not available).
Doesn’t it look as though the inflammatory response is trying desperately to throw off the tumor and not quite managing it? BCG acts by arming the T cells to act against the tumor. The granulomatous response may be the weaker and eventually failed response.
Correct answers: 21.2%
Links: 1. Pubmed
abstracts