A 35-year-old man from rural India presents with a 3-month history of productive cough, fever, and weight loss. Chest X-ray shows cavitary lesions in the apical-posterior segments of both upper lobes with minimal hilar lymphadenopathy. Sputum smear microscopy is positive for acid-fast bacilli. Which histopathological finding would best distinguish this presentation from primary progressive tuberculosis in a child?