to snoo-finity ... and beyond!
Welcome to spow's page.
Contributor score: 5
"live-born offspring" ← baited
why is it 50% females tho?
felt like an idiot after i figured out why i got this wrong.
This isn't exactly right as males can still be born as evidenced by individuals III 6,9,11. This basically an x-linked recessive disease. A carrier mother can still pass her normal X chromosome to a son (50% chance). It's just that the other 50% chance of passing an affected X chromosome results in death of the fetus in utero. Thus all males actually born will not be affected.
@suckitnbme, Correct, but if you're a live-born male, you 100% for sure do NOT have the disease, so the chance of a live-born male "being affected" is 0.
@suckitnbme it's not X-linked recessive, otherwise every single son would be affected and therefore have died in utero. It's X-linked dominant
But if you had a TSH secreting adenoma, you would NOT have had weight gain (hyperthyroid = weight loss)
Looking back, I know it's osteosarcoma but the lung metastases made me think of Ewing's
Ewing sarcoma is common in boys <15 years old. This patient is a 70 year old woman. The stem notes elevated periosteum and a sunburst pattern which are characteristic of osteosarcoma.
It would affect the dorsal column tract and the spinothalamic tract. It wont affect the spinocerebellar tract (Thus Rombergs sign in B12 deficiency will be positive)
All three of the tracts are affected in Friedrichs Ataxia
Sorry. Just checked on FA. It will also affect the spinocerebellar tract
Sensation to pinprick is DCML
Great explanation - just one addition. The retroperitoneal fibrosis could also be a direct consequence of the external beam radiation. It's linked to both causes. Either way, it's a better fit than urothelial carcinoma (in retrospect).
Why would the onset be 15 years later though?
I was thinking the same thing @spow. I had put urothelial carcinoma, thinking that a field defect would result in bilateral tumor.
But why are there no bite cells? Question stem states that there is normal morphology? That's why I didn't pick accessory spleen
Bite cells are seen when splenic macrophages take "bites" out of hemoglobin precipitates in G6PD deficiency, which doesn't have to do with our question.
This patient had a splenectomy 3 months ago, 6 weeks later showed Howell-Jolly bodies (asplenia), and then today now has normal erythrocytes (spleen is working again somehow = accessory spleen)
I was thinking that "Diffuse fibrosis" was trying to point to IgG4 Riedel Thyroiditis rather than Hashimoto's.
It's only been 10 months, per the question stem. This probably isn't long enough for fibrosis to be correct
I think this is standard for restrictive lung diseases. In obstructive the airways collapse during expiration so it's hard to expire, but there's a long drawn out end to epiration as little by little it escapes, leading to a decreased FEV1/FVC. In restrictive pt's just aren't able to move and expand their lungs enough, so when they expire it's of a small volume, but there isn't any collapse involved. It's like a normal expiration just with a restricted volume, making the FEV1/FVC normal.
@usmlecharserssss In restrictive lung diseases, the ratio is either normal or increased.
And the reason why FEV1/FVC is either normal or increased in restrictive lung disease is very simple: the FEV1 and FVC both decrease because you are restricting airflow, but the FVC will decrease MORE than the FEV1, and thus because the denominator is larger, the fraction either stays normal, or increases slightly
Contrast this to obstructive lung disease where you have an obstruction to air FLOW, e.g. the FEV1 will decrease more than the FVC, leading to a low ratio by defition
What does "fixed cardiac output" signify?
"fixed cardiac output" might mean that with the stenosis (ie. narrowed aortic valve) there is a limited or rather reduced cardiac output. Exercise would not increase cardiac output because the stenosis is caused by a mechanical (physical) rather than a biochemical process. Therefore, At any given moment the heart can not increase its output no matter how forcefully it contracts.
why not option A?arterial compression ?
@fallot4logy LVH does not lead to coronary artery compression. only reallyyyy rarely will pulmonary artery dilation cause coronary artery compression. plus that would cause angina but probably wouldnt decrease cerebral bloodflow to syncope. her murmur + LVH point us toward aortic stenosis which does cause those --> fixed CO
@fallot4logy LVH can cause coronary artery compression, but typically leading to coronary ischemia after exercise (i.e. stable angina in this patient). The question is asking what leads to her syncope. Syncope actually means her brain is lacking blood supply abruptly.
how do we rule out mitral valve prolapse in this case?
@rainlad murmurs at the right upper sternal border are aortic in nature. Mitral murmurs are heard at left 5th intercostal at the midaxillary line.