A patient comes to your office with a history of skin cancer. He tells you that the skin lesions were especially prevalent when he worked outdoors as a construction worker. You conclude that this patient's cancer is due to a defect in his skin cells. This defect is most likely due to an abnormality in which of the following enzyme systems?A. poly-A polymerase activityB. DNA repair mechanismC. DNA polymerase activityD. helicase activityE. protein synthesis machinery

A 50-year-old patient who smokes cigarettes and has lung cancer, asks how nicotine, just a small, organic molecule can cause disease. A physician says that nicotine is a carcinogen that promotes excessive growth in cells of the patient's lungs resulting in cancerous tumors. Nicotine and other carcinogens cause uncontrolled cell growth and cancer by promoting errors in what cellular event?A. Protein synthesisB. RNA transcriptionC. DNA synthesisD. DNA supercoilingE. Protein targeting

A 28-year-old woman is seen by her primary care physician because she is concerned about a mole on her abdomen that has shown changes over the past several months. Upon questioning, the doctor learns that the patient spent several summers tanning in her youth and has used a sunlamp in the previous year. A biopsy is done and a diagnosis of cutaneous malignant melanoma is made. In this instance, ultraviolet light exposure has acted as aA. CarcinogenB. CongenitalC. DeletionD. MutagenE. Teratogen

In which cell function is BRCA1, a gene mutated in women with familial breast carcinoma, involved?a.Cell adhesionb.Growth inhibitionc.Signal transductiond.Cell surface channele.Transcriptional regulation and DNA repair

Matrix metalloproteinases secreted by tumor cells are important for which feature of malignant tumors?a.Desmoplasiab.Anaplasiac.Invasivenessd.Apoptosise.Differentiation

A 28-year-old woman is seen by her primary care physician because she is concerned about a mole on her abdomen that has shown changes over the past several months. Upon questioning, the doctor learns that the patient spent several summers tanning in her youth and has used a sunlamp in the previous year. A biopsy is done and a diagnosis of cutaneous malignant melanoma is made. In this instance, ultraviolet light exposure has acted as aA. CarcinogenB. CongenitalC. DeletionD. MutagenE. Teratogen

Helicobacter pylori infection predisposes to formation of gastric tumors, but the association between the bacterial infection and a gastric tumor is the strongest for

a.adenocarcinoma of the stomachb.gastrointestinal stromal tumorsc.marginal zone lymphomasd.T-cell lymphomae.Burkitt lymphoma

The best and strongest evidence links Helicobacter pylori infection with the onset of mucosa-associated B-cell lymphomas (MALTomas) of the stomach, which are also known as marginal zone lymphomas. It is thought that H. pylori activates T cells, which in turn promote polyclonal proliferation of B cells in the gastric mucosa. In this process, some cells obviously become malignant and give rise to T-cell independent low-grade monoclonal lymphomas.

A 50-year-old woman presents with a lump in her breast. A 4-cm firm and fixed mass is noted on breast examination. Excisional biopsy reveals malignant cells that form gland-like structures and solid nests, surrounded by a dense collagenous stroma. A connective tissue stain (trichrome) of the biopsy is shown in the image (FIG1). Which of the following descriptive terms best describes the blue areas observed in this specimen?

A. Colloid carcinoma B. Comedocarcinoma C. Desmoplastic changes D. Medullary carcinoma E. Papillomatosis

The answer is desmoplastic change. Secondary descriptors are used to refer to a tumors morphologic and functional characteristics

• Papillomatosis - describes frondlike structures. Medullary - signifies a soft cellular tumor, Scirrhous or desmoplastic implies dense fibrous stroma.

• Colloid carcinomas secrete abundant mucus. • Comedocarcmoma is an intra-ductal neoplasm

in which necrotic material can be expressed from the ducts

A 48-year-old nulliparous woman complains that her menstrual blood flow is more abundant than usual. An ultrasound examination reveals a polypoid mass in the uterine fundus. The patient subsequently undergoes a hysterectomy, which reveal a poorly differentiated endometrial adenocarcinoma. The development of this neoplasm was preceded by which of the following histopathologic changes in the glandular epithelium?:

A. Hyperplasia B. Hydropic swelling C. Atrophy D. Hypertrophy E. Metaplasia

Cytogenetic studies in a 40-year-old woman with Follicular lymphoma demonstrate a t (14,18) chromosomal translocation involving the bcl-2 gene. Constitutive expression of the protein encoded by the bcl-2 gene inhibits which of the following processes in this patients transformed lymphocytes?:

A. Oxidative phosphorylation B. DNA excision repair C. G1-to-S cell cycle progression D. Apoptosis E. Protein (N-linked) glycosylation

A 54-year-old woman feels a lump in her left breast. On physical examination there is an irregular, non-movable firm 3 cm upper outer quadrant mass. A mastectomy is performed. Gross examination reveals stromal invasion. Immunohistochemical staining of the cells in the mastectomy reveals the pattern seen here. Which of the following substances, which aids in matrix degradation, is most likely shown here? A Reverse transcriptase B Telomerase C DNA topoisomerase II D Protein kinase E Cathepsin

A 48-year-old previously healthy woman develops increasing malaise over the past 4 months. On physical examination there are no abnormal findings. Laboratory studies show her Hgb is 8.5 g/dL with WBC count 241,400/microliter. A bone marrow biopsy is performed and shows a 100% cellular marrow. Chromosome analysis of the cells from the marrow yields the karyotype shown here. Which of the following is the most likely diagnosis?

A Chronic myelogenous leukemia B Metastatic breast carcinoma C Myeloid hyperplasia D Granulomatous infection E Multiple myeloma

A 60-year-old man presents with a 4-month history of increasing weight loss, wheezing, and shortness of breath. He has smoked two packs of cigarettes a day lot 40 years. His past medical history is significant for emphysema and chronic bronchitis. A chest x-ray shows a 10-cm mass in the left lung Bronchoscopy discloses obstruction ol the left main stem bronchus. A biopsy is obtained (shown) Immunohistochemical studies of this biopsy specimen would most likely show strong expression of which of the following tumor markers?

(A) Alpha-fetoprotein(B) Calretinin(C) Carcinoembryonic antigen(D)Cytokeratins (E) Synapiophysin

Which mechanism affecting the genes or chromosomes accounts for the activation of the c-myc protooncogene in Burkitt lymphoma cells?

a.Overexpressionb.Amplificationc.Point mutationd.Translocatione.Inactivation of its promotor

In which cell function is BRCA1, a gene mutated in women with familial breast carcinoma, involved?

a.

Cell adhesion

b.

Growth inhibition

c.

Signal transduction

d.

Cell surface channel

e.

Transcriptional regulation and DNA repair

Germ line mutation of the Von Hippel–Lindau (VHL) gene is associated with formation of retinal angiomas and a.glioblastoma multiformeb.Oligodendrogliomac.Neurinomasd.Ependymomase.cerebellar hemangioblastomas

Von Hippel–Lindau syndrome was originally described as a syndrome comprising angiomas of the retina and hemangioblastomas of the cerebellum. It is linked to the germ line mutation of the VHL tumor suppressor gene. These patients are at risk of developing renal cell carcinoma and pheochromocytomas. Mutations of the VHL gene also have been found in sporadic renal carcinomas unrelated to Von Hippel–Lindau syndrome.

Which enzymes in the liver account for the activation of most procarcinogens into carcinogens?a.Cytochrome P-450-dependent mono-oxidasesb.Aminotransferasesc.Hydroxylasesd.Glutathione dehydrogenasee.Caspases