Table 1 Clinical and radiological comparison of intrapulmonary teratoma, hydatid cyst of lung, and lung abscess

Intrapulmonary Teratoma

• Typically cystic masses often with focal calcification and peripheral translucency

• Air fluid level is suggestive of bronchial communication if present [9, 19]

• Chest pain

• Hemoptysis

• Cough

• Trichoptysis (most specific) [19]

• Location: left upper lobe [9]

• Unilateral [19]

Hydatid cyst

• Typically, a well-defined homogenous radio-opacity

• Air fluid level in case of a complicated cyst [20]

• Usually asymptomatic for many years

• Chest pain

• Dyspnea

• Dry cough

• Hemoptysis [20]

• Location: lower lobes specially the right basal lobe

• Bilateral in 20% of the cases [20]

Acute Lung abscess

(less than 6 week)

• Usually circumscribed with not so well-defined surrounding to lung parenchyma

• Air fluid level mostly present [21]

• Productive Cough

• Fever

• Night sweats [21]

• Location: posterior segments of the upper lobes and the superior segments of the lower lobes (if caused by aspiration) [21]

• Usually unilateral [22]

Chronic lung abscess

• Usually irregular star-like shape with well-defined surrounding to lung parenchyma

• Air fluid level mostly present [21]

• Productive Cough

• Fever

• Night sweats

• Weight loss [21]

• Location: posterior segments of the upper lobes and the superior segments of the lower lobes (if caused by aspiration) [21]

• Usually unilateral [22]