Precancer Conditon Molecular Basis

19 Questions | By Chachelly | Last updated: Nov 15, 2016 | Total Attempts: 336

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1.

A 50-year-old nulliparous female presents with menorrhagia. An ultrasound examination reveals a polypoid mass in the fundus. The patient undergoes a hysterectomy, which reveals a poorly differentiated endometrial adenocarcinoma. The development of this neoplasm was preceded by which of the following changes in the glandular epithelium?
- A.
  
  Atrophy
- B.
  
  Hydropic swelling
- C.
  
  Hyperplasia
- D.
  
  Hypertrophy
- E.
  
  Metaplasia
2.

A 62-year-old man with a urinalysis revealing hematuria has cystoscopy performed, and an irregular erythematous area in the right dome is biopsied. Atypical transitional epithelial cells extend half the thickness of the epithelium, but not extending beneath the basement membrane:
- A.
  
  Hyperplasia
- B.
  
  Metaplasia
- C.
  
  Dysplasia
- D.
  
  Carcinoma in situ
- E.
  
  Carcinoma
3.

An 8-yr-old girl presents with multiple skin nodules on her face. A skin biopsy from one of the nodules shows a squamous cell carcinoma. Molecular biology reveals germline mutation in the gene encoding a nucleotide excision repair (NER) enzyme. Which of the following is the most likely diagnosis?
- A.
  
  Ataxia telengiectasia
- B.
  
  Li-Fraumeni syndrome
- C.
  
  Xeroderma pigmentosum
- D.
  
  Neurofibromatosis, type I
- E.
  
  Fanconi anemia
4.

A 33-year-old female presents with a breast lump. Her sister and mother both had breast cancer. A mammogram shows an ill-defined density in the outer quadrant of left breast. Genetic screening identifies a mutation in the BRCA1. in addition to cell cycle control, BRCA1 protein promotes which of the following cellular functions?
- A.
  
  Apoptosis
- B.
  
  Cell adhesion
- C.
  
  DNA repair
- D.
  
  Gene transcription
5.

A change in bowel habits prompts a 53-year-old woman to see her physician, who finds that the patient's stool is positive for occult blood. A colonoscopy is performed and reveals a 6 cm friable mass located in the cecum. A biopsy of this mass demonstrates a moderately differentiated adenocarcinoma. Which of the following findings is most likely to be present in this patient?
- A.
  
  K-RAS mutation in neoplastic cells
- B.
  
  Immuno-histochemical stain positive for vimentin in the neoplastic cells
- C.
  
  Translocation between chromosomes 9 and 22
- D.
  
  Translocation between chromosomes 8 and 14
6.

A 67-year-old man presents with jaundice and weight loss. An abdominal CT scan shows a mass in the head of the pancreas. A biopsy is performed. The neoplastic cells analyzed from the tumor show continued activation of cytoplasmic kinases. Which of the following oncogenes is most likely to be involved?
- A.
  
  MYC
- B.
  
  APC
- C.
  
  RAS
- D.
  
  ERBB2
- E.
  
  Sis
7.

Which of the following mechanisms is most likely to be involved in the pathogenesis of this patient’s condition?
- A.
  
  Point mutation
- B.
  
  Chromosomal translocation
- C.
  
  Gene amplification
- D.
  
  Deletion
- E.
  
  Epigenetic modification
8.

Cytogenetic studies in malignant cells from a patient with AML-M3 demonstrate a chromosomal abnormality. Which of the following genes is most likely found at the translocation site?
- A.
  
  ABL
- B.
  
  BCL-1
- C.
  
  BCL-2
- D.
  
  MYC
- E.
  
  Retinoic acid receptor (RAR)
9.

A 4-year-old African boy presents with a rapidly enlarging mass that involves the right side of his face. Based on the biopsy findings, a diagnosis of Burkitt lymphoma is made. Mutational activation of which of the following nuclear oncogenes is most likely to be present in this tumor?
- A.
  
  ERBB2
- B.
  
  P53
- C.
  
  RAS
- D.
  
  MYC
- E.
  
  APC
10.

A 45-year-old man presents with fatigue and weight loss. Physical examination reveals a generalized non-tender lymphadenopathy and hepatosplenomegaly. A biopsy from the LN shows a malignant tumor of lymphoid cells. Immuno-histochemical staining of tumor cells with antibody to BCL2 is positive in the lymphocyte cell nuclei. Which of the following mechanisms has most likely produced the lymphoma?
- A.
  
  Increased tyrosine kinase activity
- B.
  
  Lack of apoptosis
- C.
  
  Gene amplification
- D.
  
  Reduced DNA repair
- E.
  
  Loss of cell cycle inhibition
11.

The mother of a 5-year-old boy notices an enlarged abdomen. Physical examination reveals an ill-defined abdominal mass. A CT scan shows a 9-cm mass in the region of the adrenal gland. Surgical resection of the mass shows a neuroblastoma. Cytogenetic analysis shows many double minutes and homogenously staining region?
- A.
  
  BCL1 (cyclin gene)
- B.
  
  BCL2 (anti-apoptosis gene)
- C.
  
  K-RAS (GTP-binding protein gene)
- D.
  
  N-MYC (transcription factor gene)
- E.
  
  P53 ( DNA damage response gene)
12.

A 6-month-old girl is brought to the physician as the mother notices a mass on the left side of the child’s abdomen. Urinalysis shows high levels of vanillylmandelic acid (VMA). A CT scan shows an abdominal tumor with bony metastasis. Histological examination of the resected mass shows a neuroblastoma. Evaluation of the N-myc proto-oncogene in this child’s tumor will most likely demonstrate which of the following genetic changes
- A.
  
  Chromosomal translocation
- B.
  
  Exon deletion
- C.
  
  Frame-shift mutation
- D.
  
  Gene amplification
- E.
  
  Expansion of a tri-nucleotide repeat
13.

A 35-year-old man with a history of colon carcinoma undergoes a surveillance colonoscopy. It reveals hundreds of polyps in the colon and two focal 0.5 cm ulcerated areas. A biopsy from the ulcerated area reveals irregular glands penetrating the muscular layer. Which of the following molecular events is believed to occur very early in the evolution of his colonic disease process?
- A.
  
  Mutation in mismatch repair genes
- B.
  
  Inability to hydrolyze GTP-bound RAS
- C.
  
  Activation of WNT signaling pathway
- D.
  
  Loss of heterozygosity affecting p53 gene
- E.
  
  Translocation of BCL2 from mitochondria to cytoplasm
14.

A 76-year-old man presents with abdominal pain. An abdominal CT scan shows a 10-cm mass in the head of the pancreas. A biopsy shows an adenocarcinoma. Mutational analysis of the carcinoma cells show inactivation ofSMAD4 so that transcriptional activation of cyclin-dependent kinases with growth-suppressing effects is diminished. Which of the following regulatory pathways is most likely to be affected?
- A.
  
  BCL2
- B.
  
  Beta-catenin
- C.
  
  MYC
- D.
  
  P53
- E.
  
  TGF-beta
15.

A 2-year-old boy is found to have bilateral retinal tumors. Molecular studies demonstrate a germline mutation in one allele of the Rb gene. Which of the following genetic events best explains the mechanism of carcinogenesis in this patient?
- A.
  
  Balanced translocation
- B.
  
  Expansion of tri-nucleotide repeat
- C.
  
  Gene amplification
- D.
  
  Loss of heterozygosity
- E.
  
  Maternal non-disjunction
16.

A 55-year-old female presents with post-menopausal bleeding. The excised uterus on surgery shows a polypoid mass in the uterine fundus. Histology reveals a moderately differentiated adenocarcinoma. Neoplastic cells obtained from this patient would most likely show loss of function of which of the following cell cycle proteins?
- A.
  
  P53
- B.
  
  PTEN
- C.
  
  Rb
- D.
  
  RET
- E.
  
  WT-1
17.

A 50-year-old female, who has a positive history of breast cancer presents with abdominal discomfort. Physical examination reveals a palpable adnexal mass and ascites. Further investigations reveal a papillary cystadenocarcinoma of the ovary. A mutation in which of the following structures is most likely associated with this patient’s malignant process?
- A.
  
  BRCA1
- B.
  
  P53
- C.
  
  Rb
- D.
  
  VHL
- E.
  
  WT-1
18.

Which of the following molecular alterations allows neoplastic cells with limitless replicative ability in vivo and vitro?
- A.
  
  Activation of telomerase
- B.
  
  Activation of BCL2 gene
- C.
  
  Activation of VEGF
- D.
  
  Inability to repair errors in DNA replication
- E.
  
  Activation of cyclin gene
19.

Compared to normal cells, neoplastic cells would most likely show high levels of expression of which of the following proteins?
- A.
  
  Desmin
- B.
  
  Telomerase
- C.
  
  P selectin
- D.
  
  E cadherin