Kid had a viral URI then took aspirn -> Reye syndrome, a hepatic encephalopathy. There is increased ammonia production because of the liver damage, leading to hyperammonemia. This gets to the brain, is ocnverted to glutamine (an osmolyte). This causes the brain swelling.

It's not E) viral encephalitis because it implies the virus is directly causing the encephalitis. Instead, the viral infection -> aspirin -> liver damage -> ammonia -> crosses BBB -> converted to glutamine -> draws in water -> cerebral edema

https://step1.medbullets.com/gastrointestinal/107080/hepatic-encephalopathy

• Burning Abdominal Pain hours after eating = Gastric ulcer
• Black stools for 2 days = ???
• Refractory to OTC Antacids and H2 Blockers
• Sweating and Low BP
• Pancreatic Mass = most likely GASTRINOMA

Immunohistochemical labeling uses antibodies as markers for what they want to find. In this case, we're suspecting gastrin given the symptoms

Note: You should revise the function, stimulation, and site of release for each of the hormones mentioned as well

REFERENCE: Zollinger-Ellison Syndrome

This is metastatic renal cell carcinoma (FA2020 p605) for the following reasons:

• Polycythemia - this is the primary clue, as it is associated with ectopic EPO (erythropoitin) secretion in paraneoplastic syndromes (FA2020 p228), which can be caused by pheochromocytoma, renal cell carcinoma, heptocellular carcinoma, hemangioblastoma and leiomyoma. Of these, only liver and kidney would be a choice given and hepatocellular carcinoma is incorrect because he did not have any associated finding of jaundice, hepatomegaly, ascites, or anorexia (FA2020 p392). Plus, the liver does not commonly metastasize to brain whereas kidney does (FA2020 p223)
• Hypercalcemia - this is likely indicative of PTHrP secretion, and renal cell carcinoma is one of the cancers that can do this. However, this is fairly nonspecific as there are many cancers that can secrete PTHrP.
• Heamaturia - suggestive of kidney/urinary tract involvement
• Negative for carcinoembryonic antigen - this is a nonspecific marker mainly for colon and pancreatic cancers (FA2020 p226)

I cell disease —inherited lysosomal storage disorder (autosomal recessive); defect in N-acetylglucosaminyl-1-phosphotransferase --> failure of the Golgi to phosphorylate mannose residues (decrease mannose-6-phosphate) on glycoproteins -->  proteins are secreted extracellularly rather than delivered to lysosomes