Local Cancer Growth and Invasion

00:01 Welcome back.

00:02 Let's get into some additional information about how malignancy causes pathology.

00:11 We've talked about paraneoplastic syndromes, things related to molecules that are secreted by tumors.

00:18 Now we're going to talk about local growth and invasion and how the various ways that that can actually cause disease, pathology, death.

00:29 What's shown here is a surgical specimen of a bladder cancer.

00:33 It looks like there's a ring around it, a black ring that was actually the doing of the pathologist to identify surgical margins, so that when we look down the slide after we sample this, we will see black and know that that's our surgical margin.

00:47 The main point to get out of this is that the wall is the bladder, inside that black ring is markedly thickened.

00:56 And that is an infiltrative tumor that is completely replacing the normal wall structures.

01:02 A consequence of this tumor invading into the wall is that we also had ureteral obstruction.

01:09 Ureters coming in were totally obliterated by virtue of this tumor growing and squeezing them out.

01:15 And the upstream consequence in this particular malignancy of the bladder tumor is that we have massive hydronephrosis with renal failure.

01:25 Now, this is a direct effect of the tumor invading into the ureters and then having pressure back up to cause that profound hydronephrosis, markedly dilated calyceal system in the kidney, which compromises renal function.

01:39 Okay.

01:40 Another example, this is a portion of rectum.

01:44 On the right hand side, you can see actually the anal skin, and we have a tumor that has become deeply invasive, into the wall of the of the rectum.

01:57 And you can see that, in that red area, it has actually eroded into a blood vessel.

02:02 In this patient presented with massive hematochezia, that is to say bright red blood per rectum, as a result of the tumor eroding into a vessel.

02:14 Another example of direct invasion, here's rectal cancer again, and we're looking at a portion of the rectum that has had tumor erode all the way through it.

02:24 We can see that because there's a probe in the lower panel poking all the way through and the tumor, has as a result of that erosion, allowed fecal material, bacteria, stool and things like that to get into the peritoneal space around the rectum and that is causing a peritonitis.

02:49 An example of a pathologic fracture.

02:50 So pathologic fractures occur when a break in the bone occurs with activity that should not otherwise induce a break.

02:59 In this particular case, it's due to this rather large chondrosarcoma, and this happens to be in the humerus.

03:07 You can see the head of the humerus on the left hand side and the shaft on the right hand side.

03:11 This comes from a middle aged woman who was reaching into the trunk of her car to pull out a gallon of milk and her humerus fractured.

03:21 This is due to the tumor, that kind of grayish black mucoid looking thing eroding through the bone, disrupting the normal architecture.

03:31 And by direct invasion, we are getting loss of bone and being prone to a pathologic fracture.

03:39 Mesothelioma.

03:41 So the rather voluminous amounts of white material is tumor, and that is growing on the surface of the lung, and compressing the underlying lung.

03:53 In the lower left hand corner is kind of that residual lung and there was respiratory failure due to the expansion of the tumor.

04:01 So a secondary consequence of tumor invasion locally.

04:06 This is a rather unusual tumor, it's called a mucoepidermoid carcinoma, and it per se is not particularly invasive.

04:16 But in this patient, it was in the airways and was obstructing the bronchus.

04:23 It was kind of a one way valve.

04:25 The patient could breathe in and get air in and couldn't get it back out behind that obstruction.

04:32 Also, they could have bacteria be inhaled, that didn't come out with each exhalation.

04:38 So the lung behind this area of obstruction is prone to recurrent pneumonias.

04:44 And that's actually why this was taken out as a surgical specimen and we were able then to identify the mucoepidermoid carcinoma that was causing that obstruction.

04:54 This is a cardiac fibroma, an example of a benign tumor that nevertheless caused the death of the patient.

05:04 So this was a pediatric patient who had a rather large left ventricular wall fibroma.

05:10 You can see it as that white, rather large mass and it didn't metastasize, didn't go anywhere else but by compressing the ventricle, the patient died of heart failure.

05:22 This was something where we couldn't excise the tumor.

05:24 We knew it was there, but couldn't excise it because it's largely replacing a lot of the lateral wall of the left ventricle.

05:33 Glioblastoma is just another example.

05:35 GBMs, Glioblastoma multiforme are very invasive tumors, and as they expand, they can have necrosis.

05:45 They can have areas of bleeding, but they're also going to have effects due to the expansion of of the tumor within a confined space that is to say, the skull.

05:56 So you can see an artist's rendition of a glioblastoma multiforme.

06:00 This would have been the right frontal lobe of the patient if we were looking by an MRI, and we are seeing kind of the equivalent on the MRI scan on the right hand side.

06:14 And with that, we kind of talked about the ways that tumors directly can impact their host.