Related Experiment Videos
Tissue diagnosis of selected AIDS-related opportunistic infections
Abstract:
Opportunistic infections are the most common initial manifestations of AIDS and, in many instances, are first encountered in surgical specimens. Pneumocystis carinii pneumonitis is by far the most frequent infection seen in biopsy specimens of AIDS patients. Most pathologists are familiar with its histopathologic presentations from previous experience. By contrast, many other opportunistic infections are either new or present clinically and pathologically in unfamiliar ways. Cytomegalovirus affects primarily the alimentary tract and lung. Colitis is the most common presentation. Penetrating ulcers may perforate. Most often, mesenchymal cells, endothelium in particular, show the typical intranuclear and intracytoplasmic inclusion bodies. The greater the number of inclusion bodies in tissues the shorter is the survival of the patient. Mycobacterium avium-intracellulare affects mainly small intestine and lymph nodes and produces a clinical and histologic picture similar to that of Whipple's disease. Diffuse infiltrates of histiocytes stuffed with acid-fast bacilli are characteristic. Cryptosporidiosis is the most ominous enteric opportunistic infection. Protozoa attach themselves to the epithelial surface and produce severe profuse, watery diarrhea. Cryptococcosis is seen in lung, lymph node, and brain biopsy specimens. Large numbers of organisms, sometimes with deficient mucinous capsules, and little or no inflammatory reaction, are notable. Toxoplasmosis is the most common cause of neurological complications in AIDS. Brain biopsy specimens show necrosis, microglial nodules, perivascular lymphocytic infiltrates, and, in 50% of cases, trophozoites.
Insights
Opportunistic infections are common in AIDS patients, often first seen in surgical biopsies. This review details the pathology of various infections, including Cytomegalovirus, Mycobacterium avium-intracellulare, Cryptosporidiosis, Cryptococcosis, and Toxoplasmosis.
Area of Science:
- Pathology
- Infectious Diseases
- Immunology
Background:
- Opportunistic infections are primary manifestations of Acquired Immunodeficiency Syndrome (AIDS).
- Surgical specimens are crucial for diagnosing these infections.
- Familiarity with diverse histopathologic presentations is essential for accurate diagnosis.
Purpose of the Study:
- To review the histopathologic features of common opportunistic infections in AIDS patients.
- To highlight diagnostic challenges and key findings in biopsy specimens.
- To inform pathologists about less common or unusually presenting infections.
Main Methods:
- Review of histopathologic findings in surgical biopsy specimens from AIDS patients.
- Description of characteristic cellular and organismal features for each infection.
- Correlation of histopathology with clinical presentations.
Main Results:
- Pneumocystis carinii pneumonitis is the most frequent finding.
- Cytomegalovirus commonly affects the alimentary tract and lung, with characteristic inclusion bodies.
- Mycobacterium avium-intracellulare, Cryptosporidiosis, Cryptococcosis, and Toxoplasmosis present distinct histopathologic patterns relevant to diagnosis.
Conclusions:
- Accurate histopathologic identification of opportunistic infections is critical for managing AIDS.
- Understanding the varied presentations of these infections improves diagnostic yield.
- Pathologists play a key role in the early diagnosis and management of AIDS-related opportunistic infections.