Histology USMLE Step 1 Practice Question
A 67-year-old man with a 40 pack-year smoking history presents with progressive dysphagia and unintentional 12-lb weight loss over 2 months. Endoscopy reveals an irregular, ulcerated lesion at the mid-esophagus. Biopsy demonstrates infiltrating nests of malignant squamous cells with formation of keratin pearls and prominent intercellular bridges. Which of the following best explains the histologic appearance of intercellular bridges in this specimen?
Answer choices
- ATight junction proteins (claudins and occludin) sealing the epithelial barrier
- BGap junctions (connexin-43) permitting electrical and metabolic coupling
- CDesmosomes composed of desmogleins and desmocollins anchoring intermediate filamentsCorrect answer
- DAdherens junctions (E-cadherin and catenins) linking actin cytoskeletons
- EHemidesmosomes anchoring keratin filaments to the basement membrane
- FFocal adhesions connecting integrin receptors to extracellular matrix
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