MCQ Book Questions

Q60102. A 30-year-old woman complains of impaired speech and fre- quent aspiration of food. Physical examination reveals diplo- pia and drooping eyelids. A mediastinal mass is removed and diagnosed as thymoma. The symptoms of muscle weakness in this patient are caused by antibodies directed against which of the following cellular components?

Q60103. A 31-year-old man with AIDS complains of diffi culty swallow- ing. Examination of his oral cavity demonstrates whitish mem- branes covering much of his tongue and palate. Endoscopy also reveals several whitish, ulcerated lesions in the esopha- gus. These pathologic fi ndings are fundamentally caused by loss of which of the following immune cells in this patient?

Q60104. Which of the following enzymes converts the HIV genome into double-stranded DNA in host cells in the patient described in Question 15?

Q60105. A 20-year-old woman with a history of asthma and aller- gies undergoes skin testing to identify potential allergens in her environment. A positive skin reaction to ragweed in this patient would be mediated by which of the following classes of immunoglobulin?

Q60106. A 40-year-old man complains of having yellow skin and sclerae, abdominal tenderness, and dark urine. Physical examination reveals jaundice and mild hepatomegaly. Laboratory studies demonstrate elevated serum bilirubin (3.1 mg/dL), decreased serum albumin (2.5 g/dL), and prolonged prothrombin time (17 seconds). Serologic tests reveal antibodies to hepatitis B core antigen (IgG anti-HBcAg). The serum is also positive for HBsAg and HBeAg. Which of the following glycoproteins serves as the principal cell surface receptor for viral antigens on B lymphocytes in this patient?

Q60107. What glycoprotein on virally infected hepatocytes provides a target for cell-mediated cytotoxicity in the patient described in Question 9?

Q60108. A 45-year-old woman presents with a 1-year history of dry mouth and eyes. A biopsy of a minor salivary gland reveals infi ltrates of lymphocytes forming focal germinal centers. Which of the following cellular organelles is a target for autoantibodies in this patient?

Q60109. An 8-month-old boy with a history of recurrent pneumonia is found to have almost no circulating IgG. Cellular immunity is normal. His brother had this same disease and died of echo- virus encephalitis. His parents and sisters have normal serum levels of IgG. What is the appropriate diagnosis?

Q60110. A 20-year-old gardener presents to his family physician for treatment of what he describes as “poison ivy.” The patient’s hands and arms appear red and are covered with oozing blis- ters and crusts. Which of the following best describes the pathogenesis of these skin lesions?

Q60111. A 9-month-old girl with a history of recurrent pulmonary infections is found to have a congenital defi ciency of adenos- ine deaminase, which is associated with a virtual absence of lymphocytes in her peripheral lymphoid organs. What is the appropriate diagnosis?

Q60112. A 50-year-old man complains of fever, weight loss, abdomi- nal pain, and bloody urine. Physical examination reveals red-purple discoloration of the skin. Serologic fi ndings are inconclusive, but a positive P-ANCA test suggests an autoim- mune disease. Biopsy of lesional skin discloses fi brinoid necro- sis of a small muscular artery (shown in the image). Which of the following immune responses best explains the pathogen- esis of infl ammation and necrotizing vasculitis in this patient?

Q60113. A neonate develops spastic contractions on the second post- partum day. Laboratory studies show hypocalcemia. MRI stud- ies demonstrate aplasia of the thymus and parathyroid glands. What is the appropriate diagnosis?

Q60114. A 53-year-old woman complains of progressive weight loss, nervousness, and sweating (patient shown in the image). Physical examination reveals tachycardia and exophthal- mos. Her thyroid is diffusely enlarged and warm on palpa- tion. Serum levels of thyroid-stimulating hormone (TSH) are low, and levels of thyroid hormones (T3 and T4) are markedly elevated. Which of the following mechanisms of disease best explains the pathogenesis of this patient’s thyroid condition?

Q60115. A 12-month-old infant with a history of recurrent infections, eczema, generalized edema, and easy bruising is diagnosed with an X-linked, recessive, congenital immunodefi ciency. The CBC shows thrombocytopenia. What is the most likely diagnosis?

Q60116. A 24-year-old woman with leukemia receives an allogeneic bone marrow transplant. Three weeks later, she develops a skin rash and diarrhea. Liver function tests show elevated serum levels of AST and ALT. A skin biopsy discloses a sparse lymphocytic infi ltrate in the dermis and epidermis, as well as apoptotic cells in the epidermal basal cell layer. Skin rash and diarrhea in this patient are caused primarily by which of the following cells?

Q60117. A 25-year-old man presents 1 week after discovering that his left testicle is twice the normal size. Physical examina- tion reveals a nontender, testicular mass that cannot be tran- silluminated. Serum levels of alpha-fetoprotein and human chorionic gonadotropin are normal. A hemiorchiectomy is performed, and histologic examination of the surgical speci- men shows embryonal carcinoma. Compared to normal adult somatic cells, this germ cell neoplasm would most likely show high levels of expression of which of the follow- ing proteins?

Q60118. A 25-year-old woman presents for a gynecologic examina- tion. The cervical Pap smear shows “koilocytic atypia” char- acterized by perinuclear halos and wrinkled nuclei (shown in the image). A cervical biopsy reveals invasive squamous cell carcinoma. Molecular tests for human papillomavirus (HPV) in the tumor cells are positive. Which of the following mecha- nisms of disease best explains the role of HPV in the pathogen- esis of neoplasia in this patient?

Q60119. The patient described in Question 2 undergoes a hysterec- tomy. In addition to a focus of invasive carcinoma, the pathol- ogist identifi es dysplastic squamous cells occupying the entire thickness of the cervical epithelium, with no evidence of epi- thelial maturation. The basal membrane in these areas appears intact. Which of the following terms best describes this cervi- cal lesion?

Q60120. A 62-year-old woman presents with a breast lump that she dis- covered 6 days ago. A breast biopsy shows lobular carcinoma in situ. Compared to normal epithelial cells of the breast lob- ule, these malignant cells would most likely show decreased expression of which of the following proteins?

Q60121. An 80-year-old man complains of lower abdominal pain, increasing weakness, and fatigue. He has lost 16 lb (7.3 kg) in the past 6 months. The prostate-specifi c antigen test is elevated (8.5 ng/mL). Rectal examination reveals an enlarged and nodular prostate. A needle biopsy of the prostate discloses invasive prostatic adenocarcinoma. Histologic grading of this patient’s carcinoma is based primarily on which of the following criteria?