The Histopathologoid

O'Brien M J ,  Zhao Q ,  Yang S  ( 2015 )  Histopathology   66 ,  49 – 65 . DOI:  10.1111/his.12564 Colorectal serrated pathway cancers and precursors Again had another read of a free review article in Histopathology regarding colorectal serrated lesions, because lo and behold I have a diagnostic dilemma between hyperplastic polyp and sessile serrated polyp. To be continued.

... according to RCPA General Module 15-2 is: 15 or more eosinophils in a high power field OR 20-25 eosinophils in any field.

Mention the term 'serrated lesions" (of the colorectum) and immediately I will get a brief panic attack.  Based on my limited knowledge, the lesions sound and look the same.  Even when a senior teacher made a nice diagram of how to differentiate all of these lesions, it still did not hit me how things work... until today. There is a nice review article in Journal of Clinical Pathology regarding pathological diagnosis of serrated lesions by Bateman and Shepherd ( J Clin Pathol   2015 ; 68 : 585 - 591).   I think it very helpful in terms of clearing up the terminologies involved. Basically, the recommended terminology of serrated lesions in the colorectum is as follows: 1. Hyperplastic polyp 2.  Sessile serrated lesion (SSL) 3.  SSL with dysplasia 4. Traditional serrated adenoma 5. Mixed polyp Hyperplastic polyp is easy enough, but what about sessile serrated lesions?  They have listed the key histological features as follows: ...

Just mentioning presence of a Whipple's specimen in the lab would bring throngs of histopathology trainees to observe the grossing of the specimen.  It is associated with intimidating combination of organs, many margins to remember, and last but definitely not least, the lament of a trainee saying: "Where is the tumour??" When I was a second year Pathology Masters student (first year Histopathology trainee), a senior trainee taught us a simplified way to gross a Whipple's specimen.  It is the same as any other textbook, but the lack of wordiness (as compared to the textbook) make it less intimidating.                                                            (Picture from www.pancreapedia.org) 1. Margins Stomach (proximal margin) Duodenum (distal margin) Uncinate (Soft tissue margin) Anterior pancreas Common...

Had a case today about EMPD which actually was an old case from last year.  It made me open my notes, and voila!  Another bunch of pearls of wisdom. 1.  EMPD has similar features as glandular cells eg vacuolated. 2.  Differential diagnosis of EMPD to keep in mind:      i. Porocarcinoma      ii. Bowen disease 3.  However, Bowen disease is CK5/6 positive, and EMPD is negative. 4.  Another useful immunohistochemistry is p63.  P63 is supposed to be positive for primary EMPD and negative for secondary EMPD. Point number 4 caused me a headache because it was negative although clinically and histologically it does look like primary EMPD.  But like a certain teacher once said, trust your immunohistochemistry like you trust your spouse.  You can love them 100%, but you cannot trust them 100%. Holy moly!

Information regarding Histopathology in particular, and Anatomical Pathology in general, is so vast that in my four-year study, I sometimes got lost in navigating my way in terms of what I really should study for exams.  How to pass the exams, sadly, is not the same as how to navigate your life as a full-fledged Pathologist, so I am told. Thankfully, my friends and I had dedicated teachers who kept drilling us on the final two months, on what to remember for the exams.  It may seem like a training in pattern recognition (hence the deviation from real life), but remember that our undergraduate exam is a training in pattern recognition too?  Such as ABCDs of Resuscitation, how to recognise 5%, 10% and 20% dehydration, and so on.  Similar difference. As in today, I am barely 1 week old junior specialist.  My aim here is to put as much Pearls of Wisdom (or POWs as I will put it) from our dedicated teachers, which I have written as notes.  Hopefully it will ...

Here are the list of favourite exam questions that may come up.  Among them are: 1. Ovarian/testicular germ cell tumour 2. Adenomatoid tumour 3. Blue naevus 4. Chromophone cell carcinoma vs oncocytoma (Renal) 5. Mucinous carcinoma 6. Lobular carcinoma of the breast.