What are the best pathology books?

Q. I’m will be starting my pathology residency in about a year. Any suggestions for getting prepared for residency? I have been reviewing www.enjoypath.com and others, but wanted to get your opinion.

A. Good for you! When many people think of pathology (do many people think of pathology?), they think of surgical pathology – stuff that comes out of the operating room, biopsies, etc. But there are many other parts to a pathology residency, such as hematopathology, microbiology, forensic pathology, and blood banking. I’ll run through some of the books used in these areas, then I’ll tell you what I would have done if I knew then what I know now.

Surgical pathology: Rosai’s Surgical Pathology is probably the most commonly-used book; another good source is the set of AFIP Fascicles (there’s a fascicle on pretty much every organ system). These sources are too in-depth for you now (with one exception that I’ll mention in a minute), and probably too expensive. They’re more for reference than for reading through on a Sunday night. You’ll use them until you’re nauseated when you’re a resident though.

Hematopathology: The best source for this is the AFIP Fascicle on the subject: Tumors of the Bone Marrow. This is the exception to what I said above about reading the fascicles before residency – this one would be great to go through ahead of time. There’s a lot to learn, and if you go through it once, it will make a lot more sense when you get to it in your residency. It’s small enough that you can certainly get through it in a few months.

Microbiology: We used Koneman in our residency program, and I think it is a good textbook. It’s more than you’d want to go through ahead of time though; I’d use something like Clinical Microbiology Made Ridiculously Simple. It has nice drawings and mnemonics, which is something you need in microbiology.

Forensic pathology: A couple good ones for this are put out by DiMaio: a textbook (long) and a handbook (short).

Blood banking: We used McCullough’s Transfusion Medicine text in residency. Nice and short and readable. Here’s a fun game that you might want to try too.

I think if I had it to do over again, I would do three things:
1. Read Robbins. All of it. Maybe twice. I know, I know, it is a “med-school” textbook, but we used it all the time in residency. So did the attendings at times, by the way. It’s no small feat, but should be possible in a year, and it would prepare you well. You might even take notes on the histologic appearance of different tumors and diseases; you would have those to refer to during residency. You can look at websites too (like Webpath and Ed’s Pathology Notes) – and you should – but Robbins will give you a systematic and thorough review.
2. Read the AFIP bone marrow fascicle. I actually did this before my med school rotation in hematopathology, and I was so glad I did. It will make you shine when you get to your rotation.
3. Not worry about the other stuff. The other rotations will be easy enough to go through without advance preparation.

Good luck!

How to identify lymphocytes in a blood smear

Q. Currently I am in a residency course to finish up my training as a medical laboratory technician; for the next two weeks I’ll be doing nothing but cell differentials in the hematology lab. Today as I was skimming the abnormal slides I found that I was having some difficulty distinguishing lymphocytes (particularly plasmacytic lymphs) from plasma cells found in the peripheral blood. Any pointers? In addition, I’m having a similar issue making the distinction from activated lymphocytes and monocytes. Pesky lymphs…

A. Those are very legitimate questions and ones that trouble even people with lots of experience from time to time. The key to both of these problems (and most problems where you’re trying to distinguish one cell from another) is to look at the chromatin.

1. Lymphocytes vs. plasma cells vs. plasmacytoid lymphocytes

Lymphocyte chromatin has a unique look in that it is clumpy and smudgy at the same time. Check out the top photo of normal lymphs – there are light and dark areas (clumping) within the chromatin, but the distinction between the two is not sharp (it’s smudgy). It’s like you licked your thumb and smudged the chromatin. Okay, that’s a weird analogy, but whatever. Plasma cell chromatin is blocky and discrete; it is sometimes arranged in a “clock-face” pattern around the edge of the nucleus. Not smudgy. Plasmacytoid lymphs have the chromatin of a lymphocyte (clumpy and smudgy) but the cytoplasm of a plasma cell (eccentric nucleus with a clearing where the golgi apparatus is).

2. Reactive (activated) lymphocytes vs. monocytes

Reactive lymphocytes – particularly big ones – can look a lot like monocytes. Again, the key is to look at the chromatin. Large reactive lymphocytes are usually immunoblasts, and as such, they have a big nucleolus (or two). In the bottom photo, there is a big reactive lymphocyte (called a Downey 3 cell) on the right. These cells also have fine chromatin (it has to be fine, or you wouldn’t be seeing the nucleolus). Monocyte chromatin is more dense (no nucleoli) and has a “raked” appearance. It is like you dragged a tiny garden rake across the nucleus. Also, the nucleus is often kidney-bean or horse-shoe shaped, or at least has a nice indentation or two. In addition to the chromatin differences, there are cytoplasmic differences (though these are less consistent): monocyte cytoplasm is typically dishwater grey with tiny dust-like granules, whereas reactive lymphocyte cytoplasm is usually light blue (either pale light blue or a relatively bright light blue) and if granules are present, they tend to be larger.

It just takes time and practice. Show everything you’re wondering about to someone who’s been in the lab a while – that’s the best way to learn. Most techs – as you no doubt know – are really nice and very knowledgeable!