1.
A 60-year-old man with a 90 pack-year history of smoking experiences an episode of hemoptysis. A chest x-ray reveals a 5 cm right upper lobe lung mass. An FNA yields cells consistent with small cell anaplastic ("oat cell") carcinoma. O/E -Puffiness of face, pedal edema, skin bruises, BP-165/100 mm Hg. A bone scan shows no metastases. Immunohistochemical staining of tumor cells is likely to be positive for:
Correct Answer
C. ACTH
Explanation
C. Correct. Small cell carcinoma of the lung is associated with 2 important paraneoplastic syndromes. ACTH secretion leads to Cushing syndrome; ADH secretion results in a SIADH and causes hyponatremia. This patient has hypertension, skin bruising, and pedal edema S/O Cushing syndrome. B. Erythropoietin is usually elaborated by renal cell carcinomas and would result in polycythemia. D. Insulin is secreted by insulinomas and would result in hypoglycemia.
2.
A 63-year-old chronic smoker presents with a 15 kg wt loss over past 3 months. Labs: Na+ 114 mmol/L, K+ 4.1 mmol/L, Cl- 86 mmol/L, CO2 22 mmol/L, glucose 78 mg/dL, creatinine 0.9 mg/dL, BUN 20 mg/dL, alk. phos. 38 U/L, total bil 0.8 mg/dL, alb. 3.3 g/dL. CBC shows Hb 13.9 g/dL, hematocrit 41.8%, MCV 92 fL, platelets 155,000/μL, WBC count 8300/ μL. Which of the following neoplasms is most likely to be present?
Correct Answer
C. Small cell anaplastic carcinoma
Explanation
(C) He has marked hyponatremia with the syndrome of inappropriate ADH, a paraneoplastic syndrome most often due to an 'oat cell' carcinoma of the lung. A. Renal cell carcinoma is associated with polycythemia (due to erythropoietin production by the tumor). B. Colon adenocarcinoma is associated with an iron deficiency anemia (microcytic hypochromic). D. Hepatocellular carcinoma is associated with the abnormal liver profile, but not hyponatremia and smoking. E. Seminomas are associated with undescended testes.
3.
A young man from Sub-Saharan Africa with a history of Hepatitis B infection presented to the ER complaining of vague abdominal pain, intermittent fevers, and a 20-lb weight loss over the past 6 months. O/E- Diffuse abdominal tenderness, hepatomegaly, and yellow sclera. A CT scan showed a diffusely nodular liver with a dominant nodule mass. 3 cm. Which of the following serum markers is useful for monitoring the disease progression in this patient?
Correct Answer
A. AFP
Explanation
A. Correct. AFP is a useful serum tumor marker for monitoring hepatocellular carcinoma as well as yolks sac tumors of ovary and testes.
4.
Liver metastasis of a tumor that secretes carcinoembryonic antigen was found by biopsy. The lung, pancreas, gall bladder, and stomach were devoid of tumors. What is the most likely primary site of such a tumor?
Correct Answer
B. Colon
Explanation
B. Correct. Colon cancers secrete CEA. CEA can also be elaborated by pancreatic cancers.
5.
A neoplasm on biopsy is found to be composed predominantly of cells with spindle shape and a high N/C ratio with marked pleomorphism. These cells are vimentin-positive, cytokeratin negative, and CD45 negative by immunohistochemical staining. This neoplasm is most likely to have been diagnosed in which of the following patients:
Correct Answer
D. A 15-year-old man with a mass in left femur and lung metastases
Explanation
(D) He probably has an osteosarcoma with hematogenous metastases to lung.
6.
A 70-year-old healthy man is found to have a palpable firm nodule in the prostate gland on digital rectal examination. His serum prostate-specific antigen (PSA) is found to be elevated. The microscopic appearance seen on biopsy of the prostate will probably be most consistent with which of the following conditions:
Correct Answer
B. Adenocarcinoma of prostate
Explanation
The presence of a palpable firm nodule in the prostate gland and an elevated serum prostate-specific antigen (PSA) suggests the possibility of prostate cancer. Adenocarcinoma of the prostate is the most common type of prostate cancer, making it the most likely condition based on the given information. The other options, such as adenocarcinoma of colon, yolk sac tumor of testes, squamous cell carcinoma of lung, and malignant lymphoma, are not consistent with the clinical presentation described.
7.
A 64-year-old man has suffered and. pain for the past week. He has had a 20 kg wt loss along with withing fatigue over the past year. He has developed and. distention with lack of stools in the past 2 days. O/E, bowel sounds are reduced. An abdominal CT scan reveals a mass involving descending colon. At laparotomy, partial resection of the colon is performed, with the removal of an encircling mass in descending colon. Microscopically, the mass is found to be a moderately differentiated adenocarcinoma. Which of the following lab finding is most likely to be present in this patient?
Correct Answer
A. Microcytic hypochromic anemia
Explanation
A. Correct. Many patients of colon cancer present with occult bleeding in stools resulting in an iron deficiency anemia.
8.
Smoking predisposes to which of the following tumors?
Correct Answer
D. Bronchogenic carcinoma
Explanation
. Correct. Bronchogenic carcinoma refers to carcinoma arising from the lining epithelium of the bronchus. The tumors may be squamous cell carcinoma, adenocarcinoma, bronchoalveolar carcinoma, small cell carcinoma, or large cell carcinoma. A. Incorrect. Choriocarcinoma is a malignant neoplasm of trophoblastic cells. B. Incorrect. Yolk sac tumor is a malignant germ cell tumor that differentiates along the extra-embryonic yolk sac lineage. C. Incorrect. Embryonal carcinoma is a highly malignant tumor that is composed of undifferentiated embryonic stem cells. E. Incorrect. Neuroblastoma is a malignant tumor of sympathetic ganglia and adrenal medulla that are derived from primordial neural crest cells. F. Incorrect. Multiple myeloma is a malignant tumor of terminally differentiated B-cells (plasma cells) in the bone marrow.
9.
Carcinoma of which organ has been linked to occupational exposure to aniline dyes?
Correct Answer
E. Bladder
Explanation
Answer. E- Bladder cancer is associated with exposure to aniline dyes, rubber; drugs like cyclophosphamide and parasites like schistosoma hematobium.
B, C. Breast and kidney cancers are not associated with aniline dye.
C. Lung cancer is associated with exposure to polycyclic hydrocarbons, arsenic, nickel and absestos.
10.
A 51-year-old man has worked in a factory producing plastic pipe. He has weight loss, nausea, and vomiting. His serum alkaline phosphatase is 405 U/L with AST 67 U/L, ALT 55 U/L, total bilirubin 1.2 mg/dL. An abd. CT scan reveals a 12 cm right liver lobe mass. Liver biopsy reveals a neoplasm composed of spindle cells forming irregular vascular channels. The cells demonstrate vimentin positivity and cytokeratin negativity with IHC staining. Exposure to which of the following substances
Correct Answer
E. Vinyl chloride
Explanation
Answer. E. Exposure to plastics or vinyl chloride can result in a rare, but the highly malignant tumor in the liver – angiosarcoma. Benzene exposure is associated with leukemias and lymphomas. B Radon is the 2nd most common cause of lung cancer. C Cyclophosphamide is associated with cancer of the urinary bladder. D Asbestos is strongly associated with malignant mesothelioma and is also a risk factor for lung cancer.
11.
A 1.2 cm darkly pigmented skin lesion is excised from the dorsum of the right hand of a previously healthy 42-year-old man. He noted that this lesion had become larger and darker with more irregular outlines over the past 3 mths. Several non-tender enlarged lymph nodes are palpable in the right axilla. Which of the following risk factors is most important for the development of this neoplasm:
Correct Answer
E. Chronic exposure to ultraviolet radiation
Explanation
E. Correct. Risk of melanoma increases with increasing exposure to uv radiation.
12.
A 56-year-old man has had a chronic cough for the past year. He is a non-smoker. He recently had an episode of hemoptysis. A chest x-ray demonstrates a 6 cm peri-hilar mass. A sputum sample is collected, and the sputum cytology report reads "Atypical cells present suggestive of squamous cell carcinoma." Which of the following environmental exposures is most likely to be associated with these findings?
Correct Answer
B. Radon
Explanation
B. Correct. Smoking and radon exposure are the two most important risk factors for lung cancer.
13.
A 22-year-old woman has a palpable nodule in the right lobe of her thyroid gland. An FNA of the nodule reveals cells present consistent with papillary carcinoma of the thyroid. No LN noted. Chest x-ray – normal; no positive family history. She works as a secretary for an accounting firm part-time and is earning a college degree. Which of the following findings would you consider most relevant in her past history:
Correct Answer
B. Radiation therapy in childhood
Explanation
Answer. B. papillary carcinomas of thyroid are associated with exposure to radiation. Other cancers associated with radiation are leukemias and lymphomas. A. Chronic alcoholism is associated with cancers of the liver, oral cavity, and esophagus. C. Ataxia-telangiectasia is associated with leukemias and lymphomas. D. Arsenic exposure is associated with lung and skin cancer. E. DES exposure in utero results in a clear cell adenocarcinoma of the vagina
14.
A 26-year-old student incurs a needlestick injury while starting an IV on a combative patient in the ER. He thinks no more about it, but 25 yrs later, he has increasing malaise along with a 5 kg wt loss over 5 months. On examination, his liver edge is firm. An abdominal CT scan shows a 7 cm mass in the right lobe of his liver. Which of the following neoplasms, is the most likely to have?
Correct Answer
B. Hepatocellular carcinoma
Explanation
(B) CORRECT. Hepatitis B and C infection are the most likely infections acquired via needlestick injury--2 to 6% risk per needlestick (HIV infection can occur, too, but is much less likely to occur--with a risk of <0.3%) Viral hepatitis carries the potential risk for development of hepatocellular carcinoma. Worldwide, this is the most common cause of hepatocellular carcinoma. A Hepatoblastoma is rare cancer occurring in children and is not associated with needle stick injuries. C. Hepatic angiosarcomas are associated with exposure to vinyl chloride. D. Cholangiocarcinoma is associated with infestation with liver flukes. E. Hepatic adenomas are associated with anabolic steroids and the use of oral contraceptives.