Ghon's complex
Ghon's complexis alesionseen in thelungthat is caused bytuberculosis.[1][2]The lesions consist of aGhon focusalong with pulmonarylymphadenopathywithin a nearby pulmonarylymph node.A Ghon's complex retains viablebacteria,making them sources of long-terminfection,which may reactivate and trigger secondary tuberculosis later in life.[3]
In countries where cowmilkinfected withMycobacterium bovishas been eliminated (due to culling of infected cows andpasteurization), primary tuberculosis is usually caused byMycobacterium tuberculosisand almost always begins in the lungs. Typically, the inhaledbacilliimplant in the distal airspaces of the lower part of the upper lobe or the upper part of the lower lobe, usually close to thepleura.As sensitization develops, a 1 to 1.5 cm area of gray-whiteinflammationwith consolidation emerges, known as theGhon focus.In most cases, the center of this focus undergoescaseous necrosis.Tuberclebacilli, either free or withinphagocytes,drain to theregional nodes,which also often caseate. This combination ofparenchymal lung lesionandnodal involvementis referred to as the Ghon complex. During the first few weeks, there is also lymphatic andhematogenous disseminationto other parts of the body.[citation needed]
In approximately 95% of cases, development ofcell-mediated immunitycontrols the infection.[citation needed]
Differentiation[edit]
The Ghon complex undergoes progressivefibrosis,often followed by radiologically detectablecalcification(Ranke complex), and despite seeding of other organs, no lesions develop. Although they are often confused, Ranke complex and Ghon complex are not synonymous. The Ranke complex is an evolution of the Ghon complex (resulting from further healing and calcification of the lesion).[4][5]
The Ghon complex is named after Austrian pathologistAnton Ghon;the Ranke complex is named in honour of German pulmonologistKarl Ernst Ranke.[6]
References[edit]
- ^Ghon's primary lesionWhonamedit.com, Accessed 21 January 2008
- ^Ober WB (1983). "Ghon but not forgotten: Anton Ghon and his complex".Pathol Annu.18 Pt 2: 79–85.PMID6371678.
- ^Curvo-Semedo L, Teixeira L, Caseiro-Alves F (2005). "Tuberculosis of the chest".Eur J Radiol.55(2): 158–72.doi:10.1016/j.ejrad.2005.04.014.hdl:10400.4/306.PMID15905057.
- ^Robbins and Cotran pathologic basis of disease. – 8th ed. / Vinay Kumar…[et al.] 2010.
- ^Robbins and Cotran pathologic basis of disease. – 8th ed. / Anand Athwal…[et al.] 2010.
- ^Ghon's primary lesionatWho Named It