Figure 1: Chest X-Ray PA View


Figure 2: CT Thorax Lung window
Figure3: CT Thorax Lung window


Figure 1: Chest X-Ray PA View shows multiple 1-3mm nodules, which are uniform in size and uniformly distributed
Figure 2: CT Thorax Lung window  shows multiple small nodules, which are uniform in size
Figure3: CT Thorax Lung window shows multiple small nodules, which are uniformly distributed



  • Widespread haematogenous dissemination of Mycobacterium Tuberculosis
  • So named because the nodules are the size of millet seeds(1-5mm with a mean of 2 mm)
  • Miliary TB represents only 1-3% of all cases of TB
  • Older men, African Americans and pregnant women are susceptible
  • Seen both in primary and post-primary tuberculosis and may be associated with tuberculous infection in numerous other tissues and organs.
  • When treated, clearing is frequently rapid
  • Under age 5, there is an increased risk of meningitis 

Risk Factors 

  • Immunosuppression
  • Cancer
  • Transplantation
  • HIV
  • Malnutrition
  • Diabetes
  • Silicosis
  • End-stage renal disease

Imaging Findings

  • Takes weeks between the time of dissemination and the radiographic appearance of disease
  • Up to 30% have a normal chest radiograph
  • When first visible, they measure about 1 mm in size; they can grow to 2-5mm if left untreated
  • Produces innumerable, non-calcified nodules
  • High-resolution CT scans are more sensitive at demonstrating small nodules
  • Nodules are either sharply or poorly defined
  • Diffuse, random distribution
  • May be associated with intra- and interlobular septal thickening


  • Differential Diagnosis

  • Pneumoconiosis, especially silicosis or anthrosilicosis
  • Metastatic nodules, especially from thyroid carcinoma
  • Sarcoidosis


  • Dissemination via bloodstream to
    • Lymph nodes
    • Liver
    • Spleen
    • Skeleton
    • Kidneys
    • Adrenals
    • Prostate
    • Seminal vesicles
    • Epididymis
    • Fallopian tubes
    • Endometrium
    • Meninges 


  • If not treated, almost 100% fatal
  • With treatment, less than 10% mortality