Ranke complex

Q: What’s the definition of a Ghon lesion? show answer

A: A Ghon lesion is the initial tuberculous granuloma in the lung formed during primary tuberculosis, which appears as a round opacity 3-10 mm in diameter, usually located in the peripheral lung. The Ghon lesion may calcify in up 15% of cases when it becomes a Ghon focus, also known as a Ghon nodule.

Q: What is a Ghon complex? show answer

A: A Ghon complex or primary complex consists of a lung parenchymal tuberculous granuloma (Ghon lesion) associated with ipsilateral mediastinal or hilar lymphadenopathy, occasionally forming a dumbbell-shaped opacity due to lymphangitic stranding connecting the primary focus with the hilar lymphadenitis. The Ghon complex occurs in primary pulmonary tuberculosis (TB) infection and precedes the Ranke complex. 

Q: What are the components of the Ranke complex? show answer

A: The Ranke complex combines a calcified granuloma in the lung (Ghon nodule) associated with an ipsilateral calcified mediastinal or hilar lymph node.

Q: What does the Ranke complex represent? show answer

A: The Ranke complex represents an evolution of the Ghon complex; therefore, when calcification of the Ghon lesion occurs with the formation of a calcified pulmonary granuloma (Ghon focus) associated with calcified lymph nodes in the ipsilateral mediastinum or hilum, it is called Ranke complex, which represents a healed primary tuberculous complex. Thus, the Ranke complex corresponds to a progression of the Ghon complex, representing a healed primary pulmonary tuberculosis infection with no significant meaning. The sequelae of histoplasmosis can also produce an image identical to the Ranke complex of tuberculosis.

Q: Are there the imaging findings differences between the Ranke complex of primary tuberculosis from thoracic histoplasmosis? show answer

A: The imaging findings of the Ranke complex in sequelae of primary tuberculosis and thoracic histoplasmosis are identical.