APCON 2008 Chennai
NATIONAL
PATHOLOGY QUIZ – 6
Answers
Q 1: Hashimoto thyroiditis
Everything needed to diagnose Hashimoto thyroiditis is there – Oncocytes, lymphoid follicles and follicular disruption. The intended red herring was the presence of many giant cells. Some of you fell for it and diagnosed subacute thyroiditis. Yet others have made a diagnosis of papillary carcinoma in addition to Hashimoto thyroiditis. The nuclei in Hashimoto thyroiditis can exhibit crowding, clearing, irregular contours, and grooves, mimicking papillary carcinoma and this can be a problem in FNAC, though no evidence of it is seen in any of the pictures in this case.
Giant cells can be a feature of Hashimoto thyroiditis, though such large numbers and very big ones
are unusual. They are seen to lie singly within the follicles. In contrast, the
giant cells of subacute thyroiditis
are accompanied by granulomas and are seen around
disrupted follicles. Also, many of them contain colloid.
Correct answers: 35.7%
Links
Q 2: Fungal
Olecranon Bursitis. GMS stain.
A cystic lesion with necrotic material inside and rimmed by histiocytes and multinucleated giant cells. Back of the elbow is the site of the olecranon bursa. Subcutaneous localized bursae such the prepatellar and olecranon bursae are often the site of infectious bursitis – the common organisms being bacteria (most often Staph aureus), mycobacteria and fungi. Bacterial bursitis would show a purulent exudates and mycobacterial would contain well formed epithelioid granulomas and often caseous material.
Palisading of histiocytes and giant cells should make you suspect a fungal origin. Absence of eosinophils would preclude parasites.
The fungi may be very often so lightly stained that it is almost invisible under the H&E stain. In such cases, lowering the condenser of the microscope and increasing the light may enable you to see the fungi as retractile hyphae within giant cells. Of course, a GMS stain would be confirmatory.
See the pictures taken with the condenser in the up and down positions as well as the GMS stained slide.
Credit is given for all answers suggesting a fungal infection.
Correct answers: 31.0%
Links
Q 3: Polypoid gastric heterotopia
of small intestine
Gastric mucosa with foveolar epithelium in a polypoid configuration can be seen within the small intestine with its typical villous mucosa. Heterotopic gastric mucosa may be found anywhere in the gastrointestinal tract, most often in a Meckel's diverticulum. In the small intestinal it can be a cause for intususseption.
Correct answers: 21.4%
Links
1. Gastric heterotopia of intestinal mucosa
Q 4:
The Nobel Prize in Chemistry 2008 "for the discovery and development of
the green fluorescent protein (GFP)
The Royal Swedish Academy of Sciences has awarded the Nobel Prize in Chemistry for 2008 jointly to Osamu Shimomura, of the Marine Biological Laboratory and Boston University Medical School, Martin Chalfie of Columbia University, and Roger Y. Tsien of the University of California, San Diego "for the discovery and development of the green fluorescent protein (GFP)”.
GFP first isolated from jellyfish - which emits green fluorescence under blue light - is not toxic to living cells unlike other fluorescent substances like FITC. So it can be used to literally light up proteins in living cells. It can be used as a reporter gene to track proteins in live cells by fluorescence microscopy.
The first picture shown is that of transgenic mice with GFP gene. They were fathered by a mouse receiving a donation of spermatogonial stem cells from mice expressing green fluorescent protein. Only half the baby mice show the green color. This is because each spermatogonial stem cell has only one copy of the gene for green fluorescent protein.
The second picture is a confocal photomicrograph of a migrating cell expressing a green fluorescent protein (GFP)-tagged, actin binding protein that localizes to the leading front of the cell (right side).
Correct answers: 28.6%
Links
1. Nobel prize for Chemistry 2008
A simple one for those who have seen at least pictures of it.
1. Tissue microarray technology
95.2% have got this one right. Need I say more? Remind me not to post such easy ones next time.