NBME 22 Metastatic carcinoma (NBME Answers)

Retired NBME 22 Answers

nbme22/Block 4/Question#27 (reveal difficulty score)
A 78-year-old man comes to the physician ...
Metastatic carcinoma 🔍 / 📺 / 🌳 / 📖
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+8 upvote downvote
submitted by ∗notadoctor(175)

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Metastatic disease is more common than primary bone tumors.

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lba9587 Might be helpful to consider eg. of a lung tumor. one lesion? you’re leaning lung primary. Multiple lesions in lung? METS. Q stem here included, “numerous lytic lesions along the vertebral column.” Thus, METS. +

jurrutia Also, pain that is worse at nights and persists regardless of activity. Paget's is typically asymptomatic (although pain is the most common symptom) and would have other findings (deformities, AV shunts, etc.) +

umpalumpa increased ALP is weird, considering that the lesion is lytic.. +1

l0ud_minority @umpalumpa I agree lytic lesions don't make sense with an elevated ALP. Like an idiot I thought isolated ALP and chose Paget Disease +

+5 upvote downvote
submitted by ∗j000(17)

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multiple myeloma is the most common PRIMARY malignancy of bone (pathoma), so it's not MM.

it's not paget (lack other Sx, would also have sclerotic lesions)

mostly likely renal or lung cancer metast to the bone

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+4 upvote downvote
submitted by ∗oznefu(22)

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I’m having trouble understanding why this is a better choice than Paget disease, especially with the increased ALP?

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zelderonmorningstar Paget’s would also show some sclerosis. +5

seagull ALK is increased in bone breakdown too. Prostate loves spreading to the lumbar Spine. It's like crack-cocaine for cancer. +32

aesalmon I think the "Worse at night" lends itself more towards mets, and the pt demographics lean towards prostate cancer, which loves to go to the lumbar spine via the Batson plexus. I picked Paget but i think they would have given something more telling if they wanted pagets, histology or another clue +2

fcambridge @seagull and aesalmon, I think you're a bit off here. Prostate mets would be osteoblastic, not osteolytic as is described in the vignette. +17

sup Yeah I chose Paget's too bcz I figured if it wasn't prostate cancer (which as @fcambridge said would present w/ osteoblastic lesions) they would give us another presenting sx of the metastatic cancer (lung, renal, skin) that might point us in that direction. I got distracted by the increased ALP too and fell for Paget :( +1

kernicterusthefrog @fcambridge, not exactly. Yes, prostate mets tends to be osteoblastic, but about 30% are found to be lytic, per this study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2768452/ Additionally, the night bone pains point to mets, and Paget's is much more commonly found in the cranial bones and appendicular skeleton, than axial. This could also be RCC mets! +

sweetmed I mainly ruled out pagets because they said the physical examination was normal. He would def have other symptoms. +4

cathartic_medstu From what I remember from Pathoma: Metastasis to bone is usually osteolytic with exception to prostate, which is osteoblastic. Therefore, stem says NUMEROUS lytic lesions and sounds more like metastasis. +5

medguru2295 If this is Metastatic cancer, it is likely MM. MM spreads to the spinal cord and causes Lytic lesions. It is NOT prostate as stated above. While Adenocarcinoma does spread to the Prostate, it produces only BLASTIC lesions. +

but prostate cancer is not lytic as blastic lesions

+5/- titanesxvi(106)

+1 upvote downvote
submitted by amphotericin(11)

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I ruled out Paget's because Paget's is usually localized, per FA, Pathoma, B&B. Although this patient definitely fits the demographic picture, prostate cancer is definitely not the only cancer that can metastasize to the bones. Because these are lytic lesions, it's probably some other cancer that's spread to the bones

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medguru2295 Possibly Multiple Myeloma. That is classic for an older person with back pain and lytic lesions in the back. +

asharm10 osteolytic- multiple myeloma, Osteoblastic- Prostate; dont think beyond this for this exam, i have never seen a question in NBME or uworld they tried to fool us off on this concept so far. +2

euchromatin69 u world 341 same concept +

skuutnasty I'd like to reiterate what's stated above... dx NOT MM in this question because MM is PRIMARY not METASTATIC @ bone (answer reads: metastatic carcinoma) <3 +

+1 upvote downvote
submitted by ∗imgdoc(183)

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Chondrosarcoma occurs in the hip or axial skeleton. I'd imagine that it is specifically located in one region rather than multiple lesions throughout the vertebra. Thats why I ruled this out.

I ruled out osteosarcoma and ewing sarcoma based on age alone. These tumors are seen in 15-25 year olds, and the clinical manifestations don't match up.

Paget's disease has an elevated Alkaline phosphatase level, but there would definitely be a sclerotic phase of bone deposition, rather than multiple osteolytic lesions. Besides, on a clinical vignette they would talk about enlarging head size, CN 8 impingement, fractures, etc. Even if you did go this route, paget's disease causes osteosarcoma, not multiple lytic lesions.

This left me with metastatic carcinoma.

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imgdoc I honestly thought this was multiple myeloma before I went the metastatic carcinoma route lol +

+0 upvote downvote
submitted by ∗paperbackwriter(161)

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I also chose Paget :/ but realized this which I didn't before:

The stages are not uniform across different bones, so you could have some bones that are in the osteoblastic stage, while others are in the lytic stage etc.

orthobullets.com/topic/8040/images/paget's%20bone%20scan.jpg

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paperbackwriter oops: https://upload.orthobullets.com/topic/8040/images/paget's%20bone%20scan.jpg +

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