There seems to be two separate issues with the current wording of this card. 1) It suggests that walled-off necrosis will always present with elevated serum amylase. 2) It has no mention of serum lipase (which UpToDate says may be elevated)
There's no evidence for this in either First Aid or Amboss regarding this.
Furthermore, I could only find two mentions of lipase and amylase in the specific context of walled-off pancreatic necrosis on UpToDate:
[https://www.uptodate.com/contents/approach-to-walled-off-pancreatic-fluid-collections-in-adults?search=pancreatic%20necrosis&topicRef=5633&source=see_link#H1288853302]
First, "Laboratory studies — An elevated lipase level is common in patients with walled-off PFCs."
Second, "....Elevated fluid amylase can also be seen in patients with intraductal papillary mucinous neoplasms communicating with the pancreatic duct. Thus, an elevated amylase level alone is not sufficient to establish a diagnosis of walled-off PFC"