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A morphological approach to the diagnosis of protozoal infections of the central nervous system.

Chimelli L - Patholog Res Int (2011)

Bottom Line: In addition, immunosuppression associated with various conditions, particularly with HIV infection, favors the occurrence of more severe manifestations and failure to respond to treatments.Predominant presentations are meningoencephalitis (trypanosomiasis), encephalopathy (cerebral malaria), or as single or multiple pseudotumoral enhancing lesions (toxoplasmosis, reactivated Chagas' disease).The immune reconstitution disease, resulting from enhancement of pathogen-specific immune responses after HAART, has altered the typical presentation of toxoplasmosis and microsporidiosis.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, University Hospital, Federal University of Rio de Janeiro, 21941-913 Rio de Janeiro, RJ, Brazil.

ABSTRACT
Protozoal infections, though endemic to certain regions, can be seen all around the world, because of the increase in travel and migration. In addition, immunosuppression associated with various conditions, particularly with HIV infection, favors the occurrence of more severe manifestations and failure to respond to treatments. The CNS may be the only affected system; when not, it is often the most severely affected. Despite information obtained from clinical, laboratory, and imaging procedures that help to narrow the differential diagnosis of intracranial infections, there are cases that need confirmation with biopsy or autopsy. Predominant presentations are meningoencephalitis (trypanosomiasis), encephalopathy (cerebral malaria), or as single or multiple pseudotumoral enhancing lesions (toxoplasmosis, reactivated Chagas' disease). The immune reconstitution disease, resulting from enhancement of pathogen-specific immune responses after HAART, has altered the typical presentation of toxoplasmosis and microsporidiosis. In this paper, a morphological approach for the diagnosis of protozoal infections affecting the CNS (amoebiasis, cerebral malaria, toxoplasmosis, trypanosomiasis, and microsporidiosis) is presented.

No MeSH data available.


Related in: MedlinePlus

Histology of acute petechiae (a) that may surround necrotic arterioles and venules (b). After resorption (c, d) there may be diffusely scattered cellular reaction after the red cells, infected and uninfected, are cleared from hemorrhage. (a, c, d) (H&E) (b) (PTAH).
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fig7: Histology of acute petechiae (a) that may surround necrotic arterioles and venules (b). After resorption (c, d) there may be diffusely scattered cellular reaction after the red cells, infected and uninfected, are cleared from hemorrhage. (a, c, d) (H&E) (b) (PTAH).

Mentions: Other neuropathological features include petechial hemorrhage in the brain parenchyma, ring hemorrhages, and Dürck's granulomas. Petechial or larger hemorrhages can occur in any part of the brain, but are most common in the white matter and may surround necrotic arterioles and venules (Figure 7). Ring hemorrhage consists of a series of concentric rings surrounding a central necrotic cerebral vessel. The outermost ring contains a mixture of parasitized erythrocytes, free pigment, and host monocytes, with an inner layer of uninfected erythrocytes and gliosis surrounding the vessel. The other lesion peculiar to the brain in malaria is the Dürck's granuloma, which are multiple circumscribed diffusely scattered cellular reaction (collections of astrocytes and microglia containing iron pigment), probably related to resorption of ring hemorrhages. It seems that ring hemorrhages and Dürck's granulomas may represent a temporal spectrum of the same lesion, granulomas being what remains after the red cells, infected and uninfected, are cleared from hemorrhage and this begins to be organized by host response. Similarly, petechial hemorrhages may be the result of vessel rupture in areas of no sequestration, where parasites and their products cannot, or have not yet elicited any host reaction [2, 16].


A morphological approach to the diagnosis of protozoal infections of the central nervous system.

Chimelli L - Patholog Res Int (2011)

Histology of acute petechiae (a) that may surround necrotic arterioles and venules (b). After resorption (c, d) there may be diffusely scattered cellular reaction after the red cells, infected and uninfected, are cleared from hemorrhage. (a, c, d) (H&E) (b) (PTAH).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3140201&req=5

fig7: Histology of acute petechiae (a) that may surround necrotic arterioles and venules (b). After resorption (c, d) there may be diffusely scattered cellular reaction after the red cells, infected and uninfected, are cleared from hemorrhage. (a, c, d) (H&E) (b) (PTAH).
Mentions: Other neuropathological features include petechial hemorrhage in the brain parenchyma, ring hemorrhages, and Dürck's granulomas. Petechial or larger hemorrhages can occur in any part of the brain, but are most common in the white matter and may surround necrotic arterioles and venules (Figure 7). Ring hemorrhage consists of a series of concentric rings surrounding a central necrotic cerebral vessel. The outermost ring contains a mixture of parasitized erythrocytes, free pigment, and host monocytes, with an inner layer of uninfected erythrocytes and gliosis surrounding the vessel. The other lesion peculiar to the brain in malaria is the Dürck's granuloma, which are multiple circumscribed diffusely scattered cellular reaction (collections of astrocytes and microglia containing iron pigment), probably related to resorption of ring hemorrhages. It seems that ring hemorrhages and Dürck's granulomas may represent a temporal spectrum of the same lesion, granulomas being what remains after the red cells, infected and uninfected, are cleared from hemorrhage and this begins to be organized by host response. Similarly, petechial hemorrhages may be the result of vessel rupture in areas of no sequestration, where parasites and their products cannot, or have not yet elicited any host reaction [2, 16].

Bottom Line: In addition, immunosuppression associated with various conditions, particularly with HIV infection, favors the occurrence of more severe manifestations and failure to respond to treatments.Predominant presentations are meningoencephalitis (trypanosomiasis), encephalopathy (cerebral malaria), or as single or multiple pseudotumoral enhancing lesions (toxoplasmosis, reactivated Chagas' disease).The immune reconstitution disease, resulting from enhancement of pathogen-specific immune responses after HAART, has altered the typical presentation of toxoplasmosis and microsporidiosis.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, University Hospital, Federal University of Rio de Janeiro, 21941-913 Rio de Janeiro, RJ, Brazil.

ABSTRACT
Protozoal infections, though endemic to certain regions, can be seen all around the world, because of the increase in travel and migration. In addition, immunosuppression associated with various conditions, particularly with HIV infection, favors the occurrence of more severe manifestations and failure to respond to treatments. The CNS may be the only affected system; when not, it is often the most severely affected. Despite information obtained from clinical, laboratory, and imaging procedures that help to narrow the differential diagnosis of intracranial infections, there are cases that need confirmation with biopsy or autopsy. Predominant presentations are meningoencephalitis (trypanosomiasis), encephalopathy (cerebral malaria), or as single or multiple pseudotumoral enhancing lesions (toxoplasmosis, reactivated Chagas' disease). The immune reconstitution disease, resulting from enhancement of pathogen-specific immune responses after HAART, has altered the typical presentation of toxoplasmosis and microsporidiosis. In this paper, a morphological approach for the diagnosis of protozoal infections affecting the CNS (amoebiasis, cerebral malaria, toxoplasmosis, trypanosomiasis, and microsporidiosis) is presented.

No MeSH data available.


Related in: MedlinePlus