USMLE Confusing endocrine Question!

[allojay]

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I was searching online and came across a certain question that seemed to perplex me. I'm not the best at endocrine, so I'd appreciate any assistance on the question.

So the question states that a patient came in with a pituitary adenoma and then underwent surgery to remove it. After the procedure, the patient now has bitemporal hemianopsia. The question then asked what hormone is increased?

Is it Prolactin? I'm not too sure..It had me stumbled.

 

[Jabbed]

I was searching online and came across a certain question that seemed to perplex me. I'm not the best at endocrine, so I'd appreciate any assistance on the question.

So the question states that a patient came in with a pituitary adenoma and then underwent surgery to remove it. After the procedure, the patient now has bitemporal hemianopsia. The question then asked what hormone is increased?

Is it Prolactin? I'm not too sure..It had me stumbled.

If it's presumably a pituitary adenoma that's refractory to surgery and there are not other sxs presented, I would choose prolactin on the basis of it being the single most common pituitary tumor (~35%). With that said, I feel like there's more to the question..

 

[allojay]

If it's presumably a pituitary adenoma that's refractory to surgery and there are not other sxs presented, I would choose prolactin on the basis of it being the single most common pituitary tumor (~35%). With that said, I feel like there's more to the question..

Thanks for your response. I agree with you that there should be more to the question but the site I read it on just provided those facts so there wasn't much to go on. But I was thinking prolactinoma as well.

 

[Brorthopedic]

Why would you still have hyper-secretion of prolactin if the tumor has been removed?

 

[Qester]

Were there options given with the question?

 

[Transposony]

So the question states that a patient came in with a pituitary adenoma and then underwent surgery to remove it. After the procedure, the patient now has bitemporal hemianopsia. The question then asked what hormone is increased?

Why would patient have bitemporal hemianopsia AFTER removal of pituitary adenoma?
What am I missing here?

 

[general987]

Was there an answer posted for this? I feel I could come up with a range of answers depending on what the answer choices entail

 

[Phloston]

Not really sure but stalk compression or severance for whatever reason leads to lack of dopamine-mediated inhibition of prolactin. Ergo increased prolactin.

Otherwise craniopharyngioma (not a true pituitary tumour) is specifically known for high rate of recurrence following surgical excision. Those are obviously non-secretory but mass effect could compress the stalk. So I'd go with prolactin.

 

[plasmodium]

GnRH.

 

[allojay]

Why would you still have hyper-secretion of prolactin if the tumor has been removed?

That's what I was wondering! But i guess we have to assume that the tumor wasn't respected appropriately then.

 

[allojay]

Were there options given with the question?

They had no options given. The person who posted it just posed the question. Apparently they or a friend of theirs saw it on a recent exam.

But again, I think there's a lot more to the question than what was posted. But prolactin seems to be the best choice.

 

[W19]

Recurrence of these tumors is not uncommon due to incomplete resection..

 

[Transposony]

Prolactin can't be the answer since you already removed the pituitary adenoma and the patient developed bitemporal hemianopsia after the procedure.
Only possibility can be development of hematoma following surgery leading to bitemporal hemianopsia.
Now to answer correctly, answer choices are needed but in their absence my best guess would be ADH (which increases transiently following surgery) which maybe followed by DI later.

 

[plasmodium]

While I think these are all good guesses, I feel the best answer is GnRH. The sequelae of hyperprolactinemia can be most attributed to its inhibitory affects on GnRH and its downstream effects (e.g. gynecomastia, amenorrhea). Following resection, loss of prolactin-mediated inhibition of GnRH would cause it to be increased relative to presurgical levels. The bitemporal hemianopia could be explained by damage during the procedure (e.g. iatrogenic).

 

[Phloston]

Plasmodium I noticed u deleted your previous reasoning above. Why? Also if prolactin is suppressing GnRH it would take time for the gonadotrophs to resume secreting at normal levels because of prior chronic suppression. But they would eventually become normal not increased. Unless you're talking about rate of change instead of absolute levels.

 

[Blue Flame]

I saw the same question. So plot twist, apparently the choice of prolactin wasn't on there. For those of you who chose prolactin, what would be your guys' next choice? The only choice I know of is dopamine, which apparently this person's friend went with.

 

[Transposony]

An incomplete question without choices is not worth spending any more time on.

 

[slz1900]

Development of a hematoma or recurrence would probably be outside of the purview of step without an obvious hint that that was what was occurring, wouldn't it? It seems more likely that it is asking what hormone was being inhibited by high prolactin and was now increased, so I agree that GnRH makes sense.

 

[NagisaStar]

What it be a case of Nelson's syndrome? Where maybe it was an incomplete pituitary excision, and the remaining part underwent hyperplasia and is now over secreting ACTH? I know Nelson's is mainly after bilateral adrenalectomy, but you never know!