Lymphadenopathy: Introduction – White Blood Cell Pathology

00:01 Our topic here is WBC pathology.

00:04 The various lymphoid tissue that we shall take a look at in this section include the lymph node.

00:09 Examples clinically of when and how the lymph node will be affected.

00:14 It’s important that we walk through the anatomy of it.

00:18 A few words about the spleen and the thymus, all of this dealing with leukemias and lymphomas in this section in which students tend to confuse quite a bit.

00:28 But by the time we are done, you’ll be well-organized with the WBC pathology.

00:36 At first, we’ll take a look at the normal lymph node.

00:41 Think about the lymph node that we have in our body.

00:44 Think about spread that might take place within the lymph node depending as to what kind of cancer.

00:50 For example, I mentioned a few times that if it was breast cancer, a prognostic indicator there would be the axillary lymph node.

00:57 Whereas if you had a male and there was lymph node involvement with either your testicular cancer or your scrotal cancer.

01:06 If it’s testicular cancer, then the spread will be to the paraaortic.

01:10 We’ll mention these types of spreads when the time is right.

01:13 At this point, it is important for us to identify the following structures.

01:18 I’d like for us to start in the middle.

01:20 And by the middle, I mean the germinal center.

01:23 This germinal center that you’re noticing -- indentify it please – In the middle.

01:28 Responsible for B-cell type of proliferation.

01:31 Quite active.

01:33 Beyond that, you start getting into the cortex, so this will be outer side.

01:37 And we have paracortex.

01:39 The paracortex will be the area in which the T-cells are housed.

01:44 You have the subcapsular sinus and this sinus will become important to us at some point when we talk about a particular WBC pathology known as your Langerhans cell histiocytosis.

01:57 Remember once again that this is a lymph node and so therefore, just like you would have organization of many organs, the cortex will always be the outer.

02:06 The medulla will always be the inner.

02:09 Therefore, in the middle here, we have the medulla.

02:11 And through here, you might find macrophages and company that might be located as eventually making way through what’s known as the afferent and efferent lymphatics.

02:23 Our topic at first is benign lymphadenopathy.

02:27 What does this mean to you? “Hey, doc, it hurts.” Where? In my neck.

02:34 And upon further examination, you’d find erythema in the back of the neck with oral examination.

02:41 This to you is a good news.

02:43 Of course, you’re not going to tell the patient that you’re happy that it’s a painful lymph node.

02:47 But at least, you know most likely that it can be cured and treated And most likely due to bacterial infection.

02:55 My topic is benign lymphadenopathy here and the lymph node will be called tender.

03:00 Acute nonspecific lymphadenitis.

03:03 Inflammation of lymph node characterized by cortical and/or paracortical hyperplasia.

03:08 Acute.

03:11 Usually caused by acute infections and by acute infection, we’ll be having strep or staph being the most common.

03:18 Maybe perhaps causing pharyngitis.

03:23 Cat-scratch disease.

03:25 A cat-scratch disease is rather interesting.

03:27 If you have an immunocompetent patient and gets scratched by a cat and maybe perhaps passes off a bacteria called Bartonella henselae.

03:37 I mentioned immunocompetent whereas you have a patient who is immunocompromised, maybe perhaps HIV positive, completely changes the story, doesn’t it? And this patient who is HIV positive, immunocompromised, the introduction of Bartonella in such a patient results in a skin manifestation known as bacillary angiomatosis.

03:56 It changes a complexion completely.

04:01 Tularaemia.

04:03 Tularaemia will be let’s say your patient that goes into the woods, goes for hunting and then ends up developing an acute infection.

04:11 And so therefore, we talk about rabbits.

04:17 Most frequent presentation would be tender enlarged lymph nodes, what that means is the fact that it actually hurts.

04:23 And if the lymph node hurts, this is a good news for you as a clinician.

04:26 It means that you have quite a bit of arsenal to make sure that you take care of that acute inflammation.

04:36 Whereas if it’s chronic nonspecific lymphadenitis, Usually, case is long-standing and the lymph node here, “Hey, doc." 'I have a lump on my neck.” Does it hurt? "No." Nontender lymphadenopathy.

04:50 Take a look at your differentials.

04:52 Autoimmune diseases.

04:53 HIV.

04:55 Chronic infection.

04:57 Drugs.