Neoplasm

Question 1

A patient has a tumor that you find to have a BRAF mutation. What should you suspect?

Answer 1

Melanoma. With a mutated BRAF, growth becomes independent of NRAS, and can go crazy. So you have a lot more DNA multiplication activation, lots of growth, differentiation, and survival, and ultimately: METASTASIS

Question 2

What are the 3 chronic myeloproliferative disorders, what mutations are involved with them, and what are classic clinical signs?

Answer 2

Polycythemia Vera, Essential Thrombocytosis, and Primary Myelofibrosis.
Mutations: JAK and STAT–>JAK-STAT. (JAK is a kinase, Stat isn’t).
Signs: Hepatomegaly, Splenomegaly, Pancytopenia, Tear-drop shaped cells

Question 3

From highest to lowest, list:

1) 3 most common cancers in women
2) 3 cancers that kill most women

Answer 3

1) Breast>Lung>Colon

2) Lung>Breast>Colon

Question 4

What is the most common thyroid cancer? For each type, give common characteristics:
Papillary
Follicular
Medullary
Undifferentiated/Anaplastic
Lymphoma

Answer 4

Papillary: Most common. Large cells, nuclei w/ finely dispersed chromatin and ground glass look (Orphan Annie)
Follicular: Uniform follicles, invades thyroid capsule.
Medullary: Parafollicular “C” cells, calcitonin. Amyloid stroma. MEN 2A and 2B (RET mutations)
Undiff: Older patients, invades local structures, poor prognosis.
Lymphoma: Hashimoto Thyroiditis (attacks thyroid peroxidase)

Question 5

A certain lung cancer is found to have prominent nucleoli. What enzyme found in the nucleolus would be unique to the nucleolus?

Answer 5

RNA Pol I–>produces ribosomal RNA.

Remember it transcribes the 45S pre-RNA gene, which codes for ribosomal subunits (18 S, 5.8S, 28S)