Table 2 Infectious differential diagnosis of pulmonary nodules
From: Aspergillus nodules; another presentation of Chronic Pulmonary Aspergillosis
Cause of nodule/disease | Underlying disease(s), geography | CT characteristics | Evolution |
|---|---|---|---|
Aspergillus nodule | Emphysema, asthma taking corticosteroids, smoker. Not immunocompromised. Global | Single or multiple nodules. May affect any lobe, although upper lobes most common. Unlikely to be calcified | Slow to change. May cavitate over many months. |
Coccidioidal nodule | None. Visit to, or inhabitant of, endemic area. | Usually single, upper lobes. Occasionally calcified. | Static over months or years. |
Histoplasma nodule | None. Visit to, or inhabitant of, endemic area. May report specific exposure e.g bat cave | Single or multiple. Often calcified. | Static over months or years. |
Nontuberculous mycobacterial nodule | Emphysema, corticosteroids, bronchiectasis. Global | Single or multiple. May be calcified. >5 mm diameter. | Progressive |
Pneumocystis jirovecii | Usually immunocompromised patients, HIV, steroids etc. | Single/multiple | |
Very rare cause of nodules in immunocompetent host. Global | |||
Nocardia spp. | May mimic TB | Single or multiple | |
Up to 1/3 cases occur in immunocompetent hosts. Global | |||
Dirofilariasis | None. Mosquito borne zoonosis, travel to South East Asia | Single or multiple nodules or cavities |