98. HYALEN MEMBRAN HASTALIĞI
(Neonatal Atelektazi)
Alveoller kapalı, açık olan hava yollarında hyalen membranlar
99. HYALEN MEMBRAN HASTALIĞI
(Neonatal Atelektazi)
Alveoller kapalı, açık olan hava yollarında hyalen membranlar
Editor's Notes
The cut surface of this lung demonstrates the typical appearance of a bronchopneumonia with areas of tan-yellow consolidation. Remaining lung is dark red because of marked pulmonary congestion. Bronchopneumonia (lobular pneumonia) is characterized by patchy areas of pulmonary consolidation. These areas become almost confluent in the left lower lobe on the bottom left of the photograph.The areas of consolidation are firmer than the surrounding lung.
At higher magnification, the pattern of patchy distribution of a bronchopneumonia is seen. The consolidated areas here very closely match the pattern of lung lobules (hence the term "lobular" pneumonia).A bronchopneumonia is classically a "hospital acquired" pneumonia seen in persons already ill from another disease process. Typical bacterial organisms include: Staphylococcus aureus, Klebsiella, E. coli, Pseudomonas.
Here is the microscopic appearance of a viral pneumonia with interstitial lymphocytic infiltrates. Note that there is no alveolar exudate. Thus, the patient with this type of pneumonia will probably not have a productive cough. The most common causes for viral pneumonia are influenza A and B, parainfluenza, adenovirus, human metapneumovirus, and respiratory syncytial virus (RSV appears mostly in children). Cytomegalovirus can appear in immunocompromised hosts.
Influenza A viral virulence varies considerably, as the virus undergoes genetic drift and shift with recombinations of its segmented RNA genome, particulary with shift when there are cross species shift, most often involving birds and swine. Examples include: H1N1, H1N5, H7N9.
This is respiratory syntytial virus (RSV) in a child. Note the giant cells which are part of the viral cytopathic effect. The inset demonstrates a typical giant cell with a round, pink intracytoplasmic inclusion. RSV accounts for many cases of pneumonia in children under 2 years, and can be a cause for death in infants 1 to 6 months of age or older.
The Ghon complex is seen here at closer range. Primary tuberculosis is the pattern seen with initial infection with tuberculosis in children. Reactivation, or secondary tuberculosis, is more typically seen in adults
There is a small tan-yellow subpleural granuloma in the mid-lung field on the right. In the hilum is a small yellow tan granuloma in a hilar lymph node next to a bronchus. This is the "Ghon complex" that is the characteristic gross appearance with primary tuberculosis. In most persons, the granulomatous disease will not progress. Over time, the granulomas decrease in size and can calcify, leaving a focal calcified spot on a chest radiograph that suggests remote granulomatous disease.