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?
- A)Tight junction proteins (claudins and occludin) sealing the epithelial barrier
- B)Gap junctions (connexin-43) permitting electrical and metabolic coupling
- C)Desmosomes composed of desmogleins and desmocollins anchoring intermediate filamentsGABARITO
- D)Adherens junctions (E-cadherin and catenins) linking actin cytoskeletons
- E)Hemidesmosomes anchoring keratin filaments to the basement membrane
Explicação
Intercellular bridges represent desmosomes (maculae adherentes), which are strong cell-cell adhesion structures characteristic of squamous epithelium. Desmosomes are composed of desmogleins (cadherin-type adhesion molecules) and desmocollins on the cell membra... Ver explicação completa e trilha adaptativa →