A 42-year-old male presents with shortness of breath, cough, hemoptysis, and fever following an influenza infection

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Here?s the updated caption with the explanation regarding hemorrhage vs. edema added to the Comment section:
Staphylococcus aureus Necrotizing Pneumonia
A 42-year-old male presents with shortness of breath, cough, hemoptysis, and fever following an influenza infection.
Findings
(a) Frontal chest radiograph shows a right upper lobe (RUL) consolidation with surrounding ground-glass opacities (GGO).
(b, c) Axial CT demonstrates anterior segmental consolidation in the RUL with cavitation and surrounding GGO, consistent with necrotizing pneumonia.
(d) Coronal CT reveals focal RUL consolidation with air bronchograms and surrounding GGO.
(e) Sagittal CT highlights the focal consolidation and cavitating pneumonia with preserved subpleural sparing.
(f) Axial CT further confirms the cavitating consolidation surrounded by diffuse GGO.
Ashley Davidoff MD TheCommonVein.net (b12388-03)(311Lu)

Comment
Necrotizing pneumonia caused by Staphylococcus aureus, often following influenza, is characterized by rapid tissue destruction, leading to cavitation, consolidation, and surrounding ground-glass opacities (GGO). The GGO surrounding the pneumonia likely represents alveolar hemorrhage due to vascular destruction and capillary leak caused by the necrotizing process. This is supported by the clinical presentation of hemoptysis and the aggressive nature of the infection. A component of inflammatory edema may also contribute, but hemorrhage is the dominant mechanism in this context.
The subpleural sparing seen on sagittal CT is a notable feature, providing additional diagnostic clues. Differential diagnosis includes other necrotizing infections (e.g., Klebsiella, Pseudomonas) or cavitating malignancies, though the clinical history of post-influenza infection and rapid progression strongly supports a bacterial etiology.
Early recognition and aggressive treatment are critical, with a combination of broad-spectrum antibiotics and supportive care to prevent further complications.

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Staphylococcus aureus Necrotizing Pneumonia with Cavitating Consolidation
b12388-02 (311Lu)
History
A 42-year-old male presents with shortness of breath, cough, hemoptysis, and fever following an influenza infection, complicated by Staphylococcus aureus necrotizing pneumonia.
Findings
CT axial image demonstrates a cavitating consolidation in the right upper lobe (RUL) surrounded by ground-glass opacities (GGO), indicative of alveolar damage and necrosis.
The GGO exhibits subpleural sparing, a characteristic feature often seen in necrotizing infections.

Ashley Davidoff MD TheCommonVein.net (b12388-02)(310Lu)

Comment
The cavitating consolidation is a hallmark of necrotizing pneumonia, caused by the destructive effects of Staphylococcus aureus, a known complication of post-influenza infections. The surrounding ground-glass opacities reflect alveolar hemorrhage or edema caused by vascular destruction and inflammation.
The subpleural sparing likely results from efficient lymphatic drainage and the mechanical forces of respiration that minimize fluid accumulation in the subpleural regions.
Radiological Pearls
Cavitating consolidations are frequently associated with necrotizing infections caused by virulent pathogens such as:
Staphylococcus aureus
Klebsiella pneumoniae
Pseudomonas aeruginosa
Mycobacterium tuberculosis
Fungal infections (e.g., Aspergillus or mucormycosis)
Anaerobic infections (e.g., aspiration pneumonia or abscesses).
Subpleural sparing in GGO is often a helpful diagnostic clue in defining the nature of the GGO, as it typically reflects an accumulation that is relatively “mobile” and more easily cleared from the subpleural regions via lymphatic drainage and mechanical forces.
Correlation with clinical symptoms (e.g., hemoptysis, fever) and history of predisposing conditions (e.g., influenza, aspiration) is critical for diagnosis.

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Staphylococcus aureus Necrotizing Pneumonia with Cavitating Consolidation
History
A 42-year-old male presents with shortness of breath, cough, hemoptysis, and fever following an influenza infection, complicated by Staphylococcus aureus necrotizing pneumonia.
Findings
CT axial magnified image demonstrates a consolidation with air bronchograms in the right upper lobe (RUL) surrounded by ground-glass opacities (GGO), indicative of alveolar damage and necrosis.
The GGO exhibits subpleural sparing, a characteristic feature often seen in necrotizing infections.
Ashley Davidoff MD TheCommonVein.net (b12388-02b)(311Lu)

 

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Staphylococcus aureus Necrotizing Pneumonia with Right Hilar Lymphadenopathy
b12388-02d (311Lu)
History
A 42-year-old male presents with shortness of breath, cough, hemoptysis, and fever following an influenza infection, complicated by Staphylococcus aureus necrotizing pneumonia.
Findings
CT axial image at the level of the pulmonary bifurcation demonstrates right-sided hilar lymphadenopathy (LAD).
The enlarged lymph node adjacent to the right main bronchus measures 11 mm, consistent with a reactive inflammatory process.

Ashley Davidoff MD TheCommonVein.net (b12388-02d)(310Lu)

Comment
The right hilar lymphadenopathy in this case likely represents a reactive inflammatory response to the right-sided necrotizing pneumonia caused by Staphylococcus aureus, a known post-influenza complication.
Reactive hilar LAD is part of the immune response to infection, with enlargement typically localized to the affected side.
While the clinical context strongly supports a reactive etiology, alternative considerations for unilateral hilar LAD include neoplastic processes (e.g., primary lung cancer or metastases) and granulomatous infections (e.g., tuberculosis).
Radiological Pearls
Right hilar lymphadenopathy appears as soft-tissue density on CT, localized adjacent to the right main bronchus.
The size of 11 mm is consistent with reactive LAD but warrants correlation with clinical and other radiological findings to exclude alternative etiologies.

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Fibrofatty Pleural Reaction Associated with Chronic Atelectasis
History
A 60-year-old male with chronic cough and a history suggestive of chronic aspiration.
Findings
Axial CT (a magnified in c) demonstrates bronchovascular thickening and crescentic atelectasis in the lateral segment of the right lower lobe (RLL) (red asterisk), and fatty proliferation along the pleural surface adjacent to the atelectasis (yellow arrowheads).
Coronal CT (b magnified in d ) reveals a rim of pleural fatty proliferation along the pleural surface adjacent to the atelectasis (red arrowheads) and fatty proliferation along the pleural surface adjacent to the atelectasis (yellow arrowheads).

Ashley Davidoff MD TheCommonVein.net (b12388-03cL)(311Lu)

Comment
The findings in the right lower lobe (RLL) represent chronic crescentic atelectasis, likely caused by chronic aspiration, accompanied by pleural fibrofatty proliferation.
? Chronic atelectasis leads to persistent pleural irritation and inflammation, stimulating localized fibrosis and reactive adipose tissue proliferation in the pleura.
? The bronchovascular thickening suggests chronic inflammatory changes, consistent with recurrent aspiration.
? The rim of fat proliferation (red arrowheads) adjacent to the atelectasis is a hallmark of chronic pleural inflammatory processes, often seen in chronic or localized injury.
Radiological Pearls
? Fatty proliferation appears as low-attenuation fat-density tissue (-50 to -150 HU) within the pleura, often seen adjacent to atelectatic lung segments.
? Crescentic atelectasis is indicative of subsegmental airway obstruction and recurrent lung collapse.

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