 So, you see a soft tissue at the attic or mesotempanum as you can see here and there's a soft tissue here. The ocular chain seems to be intact at least here but you see an air cell which looks like a coalescent cell and there is a fluid level there. And there is no osceous erosions in this particular patient. Fluid level at the mastoid. There is a history. There was an autoria here, the patient has got an ear pain and this is otomastoditis. So, this is very straightforward as long as the ocular chain is intact and there is no scutum erosion you know reasonable to suggest this is an otomastoditis. So, in acute you tend to have fluid levels. There was no sclerosis but in chronic you get start getting sclerosis and obliteration of cells. Here is a patient who has got lot of fluid attenuation, soft tissue attenuation within the middle ear and almost all of the mastoid air cells. This is again a otomastoditis. Another patient who has got a repeated inflammation and again lot of soft tissue filling some of the mastoid cells. You start getting some sclerosis here and you start getting large cells formation here. So, you start getting walls get broken down because of the pressure and enzymes and it is gradually getting coalescent and this is coalescent mastoditis and then it will lead on to sclerotic changes. Here is a soft tissue which is located in the attic non-dependent location. It is actually at the Prusak space as you can see here in the axial plane and there is blunting of the scutum. The scutum is here eroded and blunted and compared to a normal scutum which is sharp and the ocular chain is eroded. The ice cream is little eroded here. The cone is also little unhealthy and the pigment is actually eroded. So, you got a diagnosis which I am sure everybody knows now is a colostatoma. So, this is a easy diagnosis to make. So, if you see a soft tissue you look for all these abnormal disc. Look at the tegman, look at the location of the ossicles, look at the erosions on this side or that side, look at the scutum. This also gives you contributory information to make the diagnosis of colostatoma. Then you have to look for the complications and that is where the key thing for radiologist is lying is to exclude complications because we all know that colostatoma is a benign lesion but it is an expanding and a destructive epithelial lesion. Here there is ocular chain erosion, here there is the tegman is thin and eroded, it is significantly eroded and it is also extending into the internal layer, there is complete erosion here and there is also erosion of the lateral wall as well. The complications are here for you to see. So, this is one of the classifications and we all wanted to give some classifications in every lecture but as you can see parts flacida, parts tensor, colostatomas, secondary to perforation or congenital and the location classification is one thing so called the spam system. The difficult access sites, the sinus tympanic colostatoma, anterior epithympanic resist colostatoma comes under this so called S, then the tympanic colostatoma tick location and mastoid location and the difficult access sites are the S1 and S2. So stage one is if it is in one location, stage two is two or more, stage three is extra cranial intra temporal complications like lateral semicircular canal erosion and stage four has gone into the intra cranial complications. I don't routinely use this, I just tell the description, I don't tell is there any complications specifically there is one paragraph dedicated for eggman erosion and all those things, it is there, it is not there, I tend to mention it and here is a patient, large soft tissue eroding the sinus plate, eroding the tegman, eroding the semicircular canal and forming a labyrinthine fistula. So this is again, if you look for it you will be able to see it every time and again you can see the defect and it is not a big science here and here is a patient is ice cream is intact but the cone is eroded as you can see that is normal, that is abnormal and there is here another soft tissue here which is actually going close to the horizontal facial canal and that is something you might want to mention to your clinician that the soft tissue is very close to the inferior margin of the horizontal facial canal and another patient was eroded and going into the external ear. Colostatoma can come into the external ear either from the middle ear and occasionally dino within the external artery canal. Another patient who has got a soft tissue here eroding and then you do a CT scan and see an abscess formation in the temporal fossa, again a complication of colostatoma with an intracranial complication and this patient who has got a lot of erosions involving the facial canal here near the first part of the facial canal and the horizontal facial canal area is also involved with the horizontal semicircular canal is also eroded and there is also a little expansion which is happening at the posterior genus in the region of facial canal. This patient did not have any history of surgery but there was some sort of a defect which was happening and patient had a history of something discharges. This is like an auto mast atectomy created by the colostatoma. Another patient you can see here the scutum is intact a child there is a soft tissue here there is thinning an expansion of the lateral mastoid wall the segment is intact there is some blunting of the head of malleus and there was no history of ear discharge or infections but there is there is there is an ocular chain erosion and this is where you suggest the possibility of a congenital colostatoma. So congenital colostatoma usually this scutum is intact and there is no history of ear discharge. Sometimes it is difficult sometimes it is difficult and it's the sort of location which is commonly mentioned in textbooks but often it's sort of there everywhere. It's a young male patient presented with meatal stenosis and hearing loss they thought it was a congenital middle ear anomaly then you can see here large lesion large lesion here within the right mastoid middle ear going everywhere and you can see it here and then we give final diagnosis was actually a congenital colostatoma in this patient and this patient we did an MRI as well as you can see MR the appearances of colostatoma is a high signal on T2 low signal on T1 does not show enhancement following contrast because these are all non vascular epithelial pearls and shows sometimes a remanagement and you can see here sometimes a thin remanagement can be present due to marginal granulation and non EPIDWI imaging has been promoted as one of the areas to pick up colostatoma if you are not sure what it is and and this is called non EPIDWI in Phillips turbospin echo DWI in Siemens propeller in GE and and and there's some papers published on this as well so here is a patient who has got surgery done there are some soft tissue still there they wanted to know is that a colostatoma or not so already surgery done so it's very difficult for you to suggest is that a colostatoma or not the non EPIDWI you see this diffusion restriction and it gives a confidence to say yes there is some residual colostatoma is left another patient who is actually a child discharge was there and the patient was having a sinus plate erosion there's a defect there is ocular chain erosion this was from last month and there is also Tegman thinning and we all know this is a colostatoma and because of the sinus plate erosion and thinning we did an MRI and during the MRI did the venogram make sure it is intact but also did the non EPIDWI you can see this diffusion restriction in a colostatoma and this was confirmed on surgery so different patient who has got an ocular long standing ear discharge and you start seeing small bony spicules surrounding the ossicles so that means it is you can see this tiny bony spicules so this is this is actually a long-standing disease a soft tissue in the middle ear with classification calcification and this is tympanosclerosis