Achondroplasia

Achondroplasia is basically is of the most common forms of dwarfism. So obviously is marked by short arms, short legs, and a rather large forehead (frontal bossing). Midface hypotonia *decreased muscle tone* is another characteristic that is an obvious sign, especially in childhood. Spinal curvatures are also common. Motor skills are usually delayed, but life span and intelligence are usually normal. Though in rare cases, this deformity could block an infant’s airway or cause compression on the spinal cord.

This pathology is due to genetics believe it or not! Well, to be more specific, a mutation a certain gene; to be even more specific, the gene FGFR3. So in order to detect this certain mutation, ‘molecular genetic testing’ must be done. This testing is in fact 99% efficient in detecting this mutation. Another form of diagnosis includes radiology, such as CT or MRI. But if it is undetectable in these modalities, then the molecular genetic testing would be done.

This condition is irreversible, but there are ways of monitoring it. It is important to monitor height, weight, and head circumference. It is also important for MRI and CT evaluation to make sure there is no spinal cord compression or severe hypotonia.

Interesting to know, out of the children who are diagnosed with achondroplasia, 80% have both parents of normal stature, which means that the gene mutations or mostly spontaneous. But if a parent has the condition, the infant has a 50% of inheriting it. If both parents have it, the infants chances are increased to 75%.


Below is a T1 weighted MRI image of an infant with achondroplasia. notice the distinct frontal bossing.http://radpod.org/wp-content/uploads/2007/03/achondroplasia_arrows.jpg

Below is a father and a son out exercising, both diagnosed with achondroplasia.http://www.sciencemuseum.org.uk/on-line/genes/images/1-3-5-1-4-2-1-1-1-0-0.jpg

Juvenile Nasopharyngeal Angioblastoma

Juvenile Nasopharyngeal Angioblastoma is a benign tumor of the nasal cavities occurring almost entirely in males anywhere from 14 to 18 years old. The article goes on further more to say that if a female is diagnosed that this particular diagnosis should be questioned and undergo chromosomal studies…wow I know, right? It is most commonly found in the back of the nose and upper throat. This noncancerous growth is not common and occurs in about 1 in 60,000 nose and throat patients. Instead of invading surrounding tissue, it adds pressure which therefore distorts and displaces. This causes necrosis of tissue by pressure. Intracranial extension happen in about 10 to 20% of cases. How the tumor occurs no one knows for sure, but scientists predict it derives from sex-steroid tissue located in the nasal cartilage.

Symptons include bloody snot from the nose, rhinorrhea (more commonly called a runny nose), loss of hearing, eye pain, and double vision.

Treatments vary for this disease. To reduce the size of the tumor, doctors can use hormonal treatments, chemotherapy, or external beam irradiation. Surgery greatly depends on the location and the size of the tumor. CTs and MRIs help map out the possibility of this option, as well as help diagnose this disease.


Below is a junvile boy with angiofibroma. Notice the bulge of his eyes and middle of his face due to the pressure of the tumor.
http://eyepathologist.com/images/KL18434.jpg

This is a contrast ehanced axial MR image of the tumorright behind and into the nasal cavity.
http://www.radpod.org/wp-content/uploads/2007/07/juvenile_angiofibroma_gd_ax.jpg

Retinoblastoma

Retinoblastoma is a type of intraocular cancer that occurs most often in children. Only about 300 children are diagnosed in the US per year. Basically it forms in the retina and is caused by a mutation in the genes. The chemicals in our DNA are vital to how our cells will function. For example, a chemical called ‘oncogenes’ tell cells how fast to divide. Then there is a chemical known as the ‘tumor suppressor’ chemical. Mutations in these genes can tell them to do the opposite, this turning off the ‘tumor suppressor’ chemical, which can very easily cause cancers.

Retinoblastoma itself affects the tumor suppressor gene Rb. This is the gene that stops uncontrolled cell growth. So when that gene becomes ineffective, if unchecked the cells can then very easily become cancerous.

Nearly three-fourths of children who are diagnosed have a white pupil, also known as leukocoria. They may also have symptons such as poorly aligned eyes are red and swollen eyes. These symptoms mentioned in the previous sentence could also be mistaken for other pathologies, such as congenital cataract, or coats disease. The main way to tell the difference is through testing; blood tests, CT’s, digital photography, or biopsy. Though biopsy is a 100% effective, doctors tend to veer away with this form of diagnosis because it could potentially spread the cancer cells elsewhere.

Since the nineteen seventies doctors and scientist have developed treatments that have gone from total eye removal, to chemo-based therapy treatments, or radiotherapy. The chemo can shrink them and from there they can use laser therapy or freezing therapy.

Notice in the picture below of a axial CT image the calcification.
http://www.eyecancer.com/ViewImage.aspx?sImgSource=2005719183420.gif&sDesc=A+CT+scan+of+a+retinoblastoma+demonstrates+calcification+within+the+right+eye+(arrow).


These are "seeds" of the disease showing through the iris.
http://www.eyecancer.com/ViewImage.aspx?sImgSource=2005719183229.gif&sDesc="Seeds"+of+retinoblastoma+have+migrated+onto+the+iris+surface.

This is the white pupil appearence 75% of children with this disease get.

http://www.eyecancer.com/Patient/Condition.aspx?nID=53&Category=Retinal+Tumors&Condition=Retinoblastoma