<prompt> Characteristic feature of viral pneumonias is ?Interstitial mononuclear infiltrationIntra-alveolar proteinaceous exudateHyaline membrane lining alveoliFibrotic septa  <response>: Ans. is a i.e., Interstitial mononuclear infiltration The predominant histological pattern in case of viral penumonias is the interstitial nature of the inflammatory reaction viually localized within the walls of the alveoli. The infiltrates are usually mononuclear cells such as -lymphocytes, histocytes, plasma cells 