Sunday, July 21, 2013

81 - Herring Bone Pattern

*We will start from basics :

*Question No.1: What is Herring?
-Answer: It is the name given to a type of fish which looks something like the figure shown below and is usually found in the shallow waters of north pacific and north atlantic.

*Question No.2: What is Herring Bone?
-Answer: The Herring Bone is nothing but the name given to the skeleton of the Herring fish, that looks something like the image shown below.

*Question No.3: What is so unique about the pattern of bones in the Herring fish skeleton, that it got the name Herring bone pattern?
-Answer: As is obvious from the image of the Herring Bone/Skeleton above, the skeleton of the herring fish has a beautiful pattern that is exploited in various industries like Cloth making and Tile making or it could just be a coincidence that the bone pattern matches the design.Have a look at the Herring Bone pattern on a cloth and on a pavement in the images below.

*Question No.4: Ok Ok Ok, But what the hell does this have to do with Medicine?
-Answer: Suppose you are the surgical oncologist/radiologist/General Surgeon/Paediatrician/Physician in a hospital and you came across a patient with a soft tissue tumor in some part of the body. The patient was operated upon and the soft tissue tumor was removed. The next step in the process is usually that the Specimen of tumor tissue is sent to the pathology department for confirmation of the diagnosis. The pathologist does all the preliminary things and finally colours it with dyes and watches the slide made from the specimen under the microscope.
                                                  If the pathologist sees the same HERRING BONE PATTERN, i was talking about previously in the slide, then the resected tumor is probably FIBROSARCOMA(congenital/infantile type or adult type). The slide will look something like the image shown below because of arrangement of cells{fibroblasts} in columns of short parallel lines with all the lines in one column sloping one way and lines in adjacent columns sloping the other way.

*It has to be remembered this same pattern can appear in a case of MONOPHASIC SYNOVIAL SARCOMA, which is another type of soft tissue tumor.

*To keep things simple - Herring Bone pattern on histology is seen in soft tissue tumors like fibrosarcoma(congenital/infantile or adult) or Monophasic synovial sarcoma.

-I would like to thank Wikipedia for the images.

Thursday, November 29, 2012

80 - Tiger eye sign (Eye of the tiger sign)

- Lets begin from the basics and go on to the main stuff ....

*At birth, the central nervous system does not contain any iron in it.

*As the child grows into an adult there is (physiologically normal) gradual deposition of iron in the central nervous system.

*The part of the central nervous system where this iron deposition is most significant is the globus pallidus.

*Given below is an axial MRI image (T1 weighted) of the brain showing the exact location of the globus pallidus.

*Now this excessive iron deposition in the globus pallidus bilaterally with a central area of gliosis and edema changes gives the appearance of tigers eyes because of the different shape of globus pallidus.

*The peripheral iron appears hypointense (black on MRI) and the central gliosis and edema changes appear hyperintense (white on MRI) giving the appearance described above.

*One of the conditions in which this occurs is Hallervorden-Spatz syndrome.

*The exact image of the tiger eye sign cannot be posted here due to copyright issues, but you can see the image here ----> click here 

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