Lab tests

Question 1

What lab value is elevated in Duchenne muscular dystrophy?

Answer 1

Creatine phosphokinase levels are elevated in Duchenne muscular dystrophy.

Duchenne muscular dystrophy is an X-linked recessive disorder

dystrophin

Question 2

When should you test for Alkaline phosphatase (ALP)

Answer 2

Alkaine phosphatase levels are considered reasonable to test when there is suspicion of abnormalities in bone, liver, or intestinal disease.

You may also see elevated levels when there is an ostruction with cholestasis because the liver will increase production of ALP

Question 3

What is a serologic marker for hepato cellular carcinoma?

Answer 3

Alpha-fetoprotein

Alpha-fetoprotein is also a tumor marker for yold sac tumors and is often elevated in pregnant patients whose fetuses have a neural tube defect

Question 4

Hepatic Encephalopathy is associated with an increase in what?

Answer 4

Ammonia

Ammonia is a waste product from protein metabolism and is usually metabolized to urea in the liver. If it is not metabolized it can persist in the blood and cause swelling in the brain, causing symptoms ranging from somnolence and asterixis (hand flapping tremor) to coma

Question 5

elevated levels of homogentisic acid in the urine are indicitive of what disorder?

Answer 5

homogentisic acid in the urine is indicitive of Alkaptonuria.

Alkaptonuria is an AR disorder that results from deficient activity of the enzyme homogentisic oxidase.

You’ll see dark pigments deposited in the joints and lumbosacral spine as well as urine that turns dark after standing

Question 6

immunohistochemical stains for leiomyosarcoma are positive for?

Answer 6

Immunohistochemical stains of liomyosarcomas are positive for desmin

Uterine sarcomas arise from the myometrium or connective tissue of the endometrium and are more aggressive than endometrial carcinomas. They are more common in black women and are most commonly leiomyosarcomas.

Leiomyosarcomas are smooth muscle tumors characterized by prominent cellular atypia, abundant mitoses, and an area of coagulative necrosis.

Desmin is an intermediate filamennt found near the Z line of sarcomeres. Desmin staining in a retroperitoneal mass would confirm the presence of a leiomyosarcoma.

Question 7

Positive staning for chromogranin would denote the presence of what?

Answer 7

Chromogranin is a secretory protein found in the vesicles of

endocrine and neuro-endocrine cells.

Positive staining would denote the presence of a neuroendocrine carcinoma (pheochromocytoma, thyroid medullary tumor, a pancreatic tumor, etc).

Question 8

Positive staning for cytokeratin would denote the presence of what type of tissue?

Answer 8

Cytokeratin is an epithelial cell stain that marks intermediate fibers. It is often used to identify squamous cells or glandular epithelium.