NBME 21 Answers ↦
(46.1 difficulty score)
An 11-year-old boy has had persistent pain in ...
Perfect way to remember it. Thank you!
Iused the mnemonic PB (lead) KeTtLe....looking at the stem it said "osteolytic mass" meaning that it has to be either Breast, Kidney, thyroid or lungs. none of the rest are options leaving lungs. but jambo2222 very noiice that works too!
@chandlerbas I think you might be using the mneumonic backwards- PB-KTL is for primary cancers that met to bone. For example, a primary lung cancer can met to bone and cause an osteolytic lesion. But in this case the primary cancer is the osteosarcoma. Meaning that the mneumonic doesn't actually apply to this question
ya you're right good stuff!! I dont know why that made sense during the question...anyways to add to the other comments...osteosarcomas are aggressive and 10% metastasize to the lungs via hematogenously at the time of diagnosis.
just to add, in terms of venous circulation everything goes to heart via vena cava and then to the lungs. The only way the bone would metastasize to these other structures would be if it continued through arterial circulation without seeding, which seems unlikely. The only ones that spread to the liver are from the PORTAL venous system, aka not bone only colon etc.
Ya, but its asking where a primary bone lesion metastasizes to. Not lung -> bone