Immunohistochemistry — MCQs

A 43-year-old man comes to the physician because of weight loss and swelling on the left side of his neck. Physical examination shows a firm, enlarged left upper cervical lymph node that is immobile. Immunohistochemical testing performed on a biopsy specimen from the lymph node stains positive for cytokeratin. Which of the following is the most likely site of the primary neoplasm in this patient?

An investigator is studying the effect of different cytokines on the growth and differentiation of B cells. The investigator isolates a population of B cells from the germinal center of a lymph node. After exposure to a particular cytokine, these B cells begin to produce an antibody that prevents attachment of pathogens to mucous membranes but does not fix complement. Which of the following cytokines is most likely responsible for the observed changes in B-cell function?

Fluorescein is an artificial dark orange colored organic molecule used in the diagnosis of corneal ulcers and herpetic corneal infections. It is observed that, in experimental animals, the fluorescein binds to receptors on certain B cells, but it does not stimulate them to produce fluorescein specific antibodies unless it is first attached to a larger molecule such as albumin. Which of the following terms best describes fluorescein?

A 45-year-old immigrant presents with unintentional weight loss, sleep hyperhidrosis, and a persistent cough. He says these symptoms have been present for quite some time. Upon imaging, many granulomas in the upper lobes are present. It is noted that these apical granulomas have centers of necrosis that appear cheese-like in appearance. Encircling the area of necrosis are large cells with cytoplasms pale in color. Of the following surface markers, which one is most closely associated with these cells?

What is the primary stimulus for erythropoietin production?

During an experiment, the immunophenotypes of different cells in a sample are determined. The cells are labeled with fluorescent antibodies specific to surface proteins, and a laser is then focused on the samples. The intensity of fluorescence created by the laser beam is then plotted on a scatter plot. The result shows most of the cells in the sample to be positive for CD8 surface protein. Which of the following cell types is most likely represented in this sample?

An investigator studying targeted therapy in patients with gastrointestinal stromal tumors requires a reliable test to determine the spatial distribution of CD117-positive cells in biopsy specimens. Which of the following is the most appropriate test?

A 7-month old boy, born to immigrant parents from Greece, presents to the hospital with pallor and abdominal distention. His parents note that they recently moved into an old apartment building and have been concerned about their son's exposure to chipped paint from the walls. On physical exam, the patient is found to have hepatosplenomegaly and frontal skull bossing. Hemoglobin electrophoresis reveals markedly increased HbF and HbA2 levels. What would be the most likely findings on a peripheral blood smear?

A 52-year-old woman sees you in your office with a complaint of new-onset headaches over the past few weeks. On exam, you find a 2 x 2 cm dark, irregularly shaped, pigmented lesion on her back. She is concerned because her father recently passed away from skin cancer. What tissue type most directly gives rise to the lesion this patient is experiencing?

An investigator is conducting a study to document the histological changes in the respiratory tree of a chronic smoker. He obtains multiple biopsy samples from the respiratory system of a previously healthy 28-year-old man. Histopathological examination of one sample shows simple cuboidal cells with a surrounding layer of smooth muscle. Chondrocytes and goblet cells are absent. This specimen was most likely obtained from which of the following parts of the respiratory system?