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DOI:10.2214/AJR.07.2193
AJR 2007; 189:1082-1087
© American Roentgen Ray Society


Pictorial Essay

Oncogenic Viruses in AIDS: Mechanisms of Disease and Intrathoracic Manifestations

Judah Burns1, Rita Shaknovich2, Jason Lau3 and Linda B. Haramati1

1 Department of Radiology, Albert Einstein College of Medicine and Montefiore Medical Center, 111 E 210th St., Bronx, NY 10467.
2 Department of Pathology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY.
3 Albert Einstein College of Medicine, Bronx, NY.

Received March 6, 2007; accepted after revision June 7, 2007.

 
Presented at the 2006 annual meeting of the American Roentgen Ray Society, Vancouver, BC, Canada.

Address correspondence to L. B. Haramati (lharamati{at}aecom.yu.edu).

CME

This article is available for CME credit. See www.arrs.org for more information.


Abstract
Top
Abstract
Introduction
Human Herpesvirus 8
Epstein-Barr Virus
Human Papillomavirus
References
 
OBJECTIVE. The objective of this article is to introduce the reader to the thoracic manifestations of neoplasms that are related to common oncogenic viruses in HIV-infected patients. We review the pathologic basis of the infections and illustrate the imaging features of their thoracic manifestations.

CONCLUSION. The intrathoracic manifestations of oncogenic viral infection in AIDS patients are protean. Understanding their epidemiologic, pathologic, and imaging features is crucial to diagnosing and managing these often-treatable conditions.

Keywords: AIDS • cancer • chest imaging • conventional radiography • CT • lungs • lymphatic system • oncogenic virus


Introduction
Top
Abstract
Introduction
Human Herpesvirus 8
Epstein-Barr Virus
Human Papillomavirus
References
 
Infection and malignancy constitute the bulk of AIDS-related disease [1]. Although the HIV virus is not itself oncogenic, HIV infection renders patients vulnerable to developing malignancies, especially those transmitted by oncogenic viruses. The important role that infection with oncogenic viruses plays in the development of malignancy has become well recognized in the past decade. Understanding the mode of viral transmission sheds light on the epidemiology of these malignancies.

Three oncogenic viruses are strongly linked to HIV-related malignancy: human herpesvirus 8 (HHV-8), Epstein-Barr virus, and human papillomavirus (Table 1). As a rule, the risk of malignant transformation is related to the degree of host immunosuppression.


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TABLE 1: HIV-Related Tumors and Their Associated Viruses

 

In this article we briefly review the mechanisms of disease and imaging features of several AIDS-related oncogenic viruses and illustrate their typical and unusual thoracic imaging manifestations.


Human Herpesvirus 8
Top
Abstract
Introduction
Human Herpesvirus 8
Epstein-Barr Virus
Human Papillomavirus
References
 
Human herpesvirus 8 is the oncogenic virus associated with Kaposi sarcoma and primary effusion lymphoma, otherwise known as body-cavity lymphoma.

Epidemiologic studies of Kaposi sarcoma, an AIDS-defining illness described early in the AIDS epidemic, revealed a disproportionate risk of developing Kaposi sarcoma in a subset of HIV-infected patients, men who had sex with men. This implicated a cofactor, rather than the HIV virus itself. HHV-8 genomic fragments were first discovered in Kaposi sarcoma specimens in 1994 [24]. The virus was seen in all groups of patients with Kaposi sarcoma, including those with classic, endemic, and transplantation- and AIDS-related disease, solidifying the link between HHV-8 and Kaposi sarcoma. In vivo, the prevalence of Kaposi sarcoma in HHV-8–infected individuals was observed to be related to the presence and degree of immunosuppression. Thus, HHV-8 infection was shown to be the causative viral agent associated with the development of Kaposi sarcoma.

Kaposi sarcoma is a spindle cell neoplasm likely derived from endothelial cell lineage. Clinically diverse, the various phenotypic manifestations of Kaposi sarcoma are histologically similar. Classic skin lesions, nodal and lymphatic involvement, and a variable clinical course typify this illness. In HIV-infected individuals, altered gene expression is seen in response to an abnormal cytokine milieu. In particular, the HIV Tat protein has been shown to stimulate growth of Kaposi sarcoma cells in vitro [5]. The development of highly active antiretroviral therapy has influenced the clinical course and reduced the incidence of Kaposi sarcoma.

Imaging features of Kaposi sarcoma include interstitial (Fig. 1A, 1B, 1C) or nodular (Fig. 2) parenchymal opacities [6, 7]. The characteristic peribronchovascular distribution is best seen on CT (Fig. 3A, 3B), and coalescence of nodules is common in late-stage disease. Pleural effusion and lymphadenopathy may also be present. Characteristically, thallium lung scanning is positive, which may discriminate Kaposi sarcoma from other infectious or inflammatory conditions.


Figure 1
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Fig. 1A 43-year-old man with HIV presenting with cutaneous Kaposi sarcoma. Open lung biopsy revealed pulmonary Kaposi sarcoma. Posteroanterior (A) and lateral (B) chest radiographs show bilateral ill-defined nodules and areas of confluence with peribronchovascular and lower lobe predominance.

 

Figure 2
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Fig. 1B 43-year-old man with HIV presenting with cutaneous Kaposi sarcoma. Open lung biopsy revealed pulmonary Kaposi sarcoma. Posteroanterior (A) and lateral (B) chest radiographs show bilateral ill-defined nodules and areas of confluence with peribronchovascular and lower lobe predominance.

 

Figure 3
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Fig. 1C 43-year-old man with HIV presenting with cutaneous Kaposi sarcoma. Open lung biopsy revealed pulmonary Kaposi sarcoma. Axial chest CT scan shows findings typical of extensive Kaposi sarcoma, including ill-defined nodules, some flame-shaped, with areas of confluent consolidation and peribronchovascular predominance.

 

Figure 4
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Fig. 2 33-year-old man with HIV infection, Kaposi sarcoma, and cough. Axial chest CT scan shows bilateral scattered ill-defined nodules, some in peribronchovascular distribution. Compared with Figure 1A, 1B, 1C, nodules are more scattered and less confluent.

 

Figure 5
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Fig. 3A 66-year-old man with Kaposi sarcoma. Posteroanterior radiograph of left chest shows thickening of interlobular septa and ill-defined peribronchovascular nodules.

 

Figure 6
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Fig. 3B 66-year-old man with Kaposi sarcoma. CT image at level of aortic arch shows thickened interlobular septa and ill-defined peribronchovascular nodules.

 
Primary effusion lymphoma is a rare type of lymphoma that is also linked to HHV-8 infection. More common in end-stage AIDS, this disease reflects plasmacytic differentiation of transformed B lymphocytes. HHV-8 is universally present, enabling growth, in part, by autocrine production of interleukin (IL)-6 and the vascular endothelial growth factor [8]. This growth is stimulated by the production of viral homologues to IL-6 and acts to inhibit apoptosis. Typically, primary effusion lymphoma manifests with widespread serosal involvement. Pleural, pericardial, and peritoneal involvement result in pleural and pericardial effusions, ascites, and serosal masses (Fig. 4A, 4B, 4C). Diagnosis requires serosal–surface biopsy or analysis of the effusion.


Figure 7
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Fig. 4A 38-year-old man with HIV infection, fever, and generalized lymphadenopathy. Pleural biopsy showed human herpesvirus 8 and Epstein-Barr virus in lymphoma cells, which is consistent with primary effusion lymphoma. CT digital radiograph shows extensive right pleural opacity, bilateral hilar and mediastinal lymphadenopathy, and splenomegaly (arrows).

 

Figure 8
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Fig. 4B 38-year-old man with HIV infection, fever, and generalized lymphadenopathy. Pleural biopsy showed human herpesvirus 8 and Epstein-Barr virus in lymphoma cells, which is consistent with primary effusion lymphoma. Axial chest CT images show large pleural (arrows, C) and chest wall mass with associated pleural effusion. Note also pronounced right axillary lymphadenopathy.

 

Figure 9
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Fig. 4C 38-year-old man with HIV infection, fever, and generalized lymphadenopathy. Pleural biopsy showed human herpesvirus 8 and Epstein-Barr virus in lymphoma cells, which is consistent with primary effusion lymphoma. Axial chest CT images show large pleural (arrows, C) and chest wall mass with associated pleural effusion. Note also pronounced right axillary lymphadenopathy.

 

Epstein-Barr Virus
Top
Abstract
Introduction
Human Herpesvirus 8
Epstein-Barr Virus
Human Papillomavirus
References
 
Epstein-Barr virus is ubiquitous in the population and is spread through the exchange of oral secretions. Epstein-Barr virus is linked to non-Hodgkin's lymphoma, Hodgkin's lymphoma, spindle cell tumors, and nasopharyngeal carcinomas.

Non-Hodgkin's lymphomas are an important malignancy among HIV-infected individuals, developing in 5–10% as an initial or subsequent AIDS-defining illness [9]. Most cases of non-Hodgkin's lymphoma are of B-cell origin and are often linked to Epstein-Barr virus infection [10]. In HIV-infected patients, de novo Epstein-Barr virus infection or reactivation of latently infected memory B lymphocytes results in the two clinical categories of disease: systemic lymphoma in 80% and primary brain lymphoma in 20%. These share heterogeneous molecular characteristics typified by neoplastic B-cell proliferation [11]. This reflects a multifactorial model of lymphomagenesis. However, although there is dysregulated humoral immunity, HIV antigens are not those driving B-cell proliferation.

HIV-associated non-Hodgkin's lymphoma presents most commonly with extranodal disease [12]. In the chest, usual features include pulmonary parenchymal nodules and masses and pleural masses and effusions (Figs. 5A, 5B, 5C and 6A, 6B). Unlike lymphoma in HIV-negative patients, lymphadenopathy is not usually the dominant imaging feature. Nevertheless, most HIV-infected patients with intrathoracic non-Hodgkin's lymphoma do have lymphadenopathy (Fig. 7A, 7B, 7C).


Figure 10
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Fig. 5A 41-year-old man with HIV infection and cough. Percutaneous biopsy revealed diffuse large B-cell lymphoma. Posteroanterior chest radiograph shows large mass in right upper and middle lobes.

 

Figure 11
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Fig. 5B 41-year-old man with HIV infection and cough. Percutaneous biopsy revealed diffuse large B-cell lymphoma. Axial chest CT scan shows large mass in right upper lobe and surrounding smaller nodules.

 

Figure 12
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Fig. 5C 41-year-old man with HIV infection and cough. Percutaneous biopsy revealed diffuse large B-cell lymphoma. Endobronchial component to mass is seen at level of right upper lobe bronchus.

 

Figure 13
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Fig. 6A 51-year-old woman with lupus and HIV infection who presented with nonresolving pneumonia. Transbronchial biopsy showed B-cell non-Hodgkin's lymphoma. Posteroanterior chest radiograph shows bilateral ill-defined pulmonary nodules and masses that are more prominent on right side.

 

Figure 14
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Fig. 6B 51-year-old woman with lupus and HIV infection who presented with nonresolving pneumonia. Transbronchial biopsy showed B-cell non-Hodgkin's lymphoma. Axial chest CT scan shows bilateral ill-defined pulmonary nodules.

 

Figure 15
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Fig. 7A 48-year-old woman with HIV infection who presented with generalized, palpable lymphadenopathy. Cervical lymph node biopsy showed diffuse large B-cell lymphoma. Posteroanterior chest radiograph shows bilateral hilar and mediastinal lymphadenopathy.

 

Figure 16
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Fig. 7B 48-year-old woman with HIV infection who presented with generalized, palpable lymphadenopathy. Cervical lymph node biopsy showed diffuse large B-cell lymphoma. Axial CT scans through mediastinum show multiple bilateral enlarged lymph nodes.

 

Figure 17
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Fig. 7C 48-year-old woman with HIV infection who presented with generalized, palpable lymphadenopathy. Cervical lymph node biopsy showed diffuse large B-cell lymphoma. Axial CT scans through mediastinum show multiple bilateral enlarged lymph nodes.

 
Hodgkin's lymphoma occurs up to eight times as frequently in HIV-infected patients as in patients without HIV infection and is strongly linked to Epstein-Barr virus infection [13]. The mixed cellularity and lymphocyte-depleted subtypes are most common. Hodgkin's disease is generally aggressive in the HIV-infected population, commonly presenting with widespread illness and an aggressive clinical course.

On imaging, Hodgkin's disease will usually present with lymphadenopathy as the dominant finding (Fig. 8A, 8B, 8C). However, extranodal disease is present in most AIDS patients who have Hodgkin's lymphoma.


Figure 18
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Fig. 8A 34-year-old man with long-standing HIV infection and 2-month history of cough. Transbronchial biopsy was negative. Bone marrow aspirate revealed Hodgkin's disease. Contrast-enhanced chest CT scans show extensive right paratracheal, right hilar, and subcarinal lymphadenopathy.

 

Figure 19
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Fig. 8B 34-year-old man with long-standing HIV infection and 2-month history of cough. Transbronchial biopsy was negative. Bone marrow aspirate revealed Hodgkin's disease. Contrast-enhanced chest CT scans show extensive right paratracheal, right hilar, and subcarinal lymphadenopathy.

 

Figure 20
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Fig. 8C 34-year-old man with long-standing HIV infection and 2-month history of cough. Transbronchial biopsy was negative. Bone marrow aspirate revealed Hodgkin's disease. CT scan at lung window setting shows patchy parenchymal opacities in right upper lobe.

 

Human Papillomavirus
Top
Abstract
Introduction
Human Herpesvirus 8
Epstein-Barr Virus
Human Papillomavirus
References
 
Various subtypes of human papillomavirus cause cervical cancer, anal cancer, and laryngotracheal papillomatosis [14].

Thoracic metastases from HIV-associated extrathoracic malignancies must be recognized and differentiated from infection [15]. Human papillomavirus–induced cervical and anal cancers commonly present with thoracic metastases. Tumorigenesis is promoted through human papillomavirus oncoprotein E6- and E7-enhanced degradation of native tumor suppressor genes p53 and RB.

On imaging, metastases from cervical and anal carcinoma may be localized or widespread (Fig. 9); pulmonary involvement is not rare and often manifests as nodules or masses. When the cervical or anal carcinoma is of the squamous subtype, necrosis is common. In that setting, lung nodules and masses are often cavitary, and lymphadenopathy is of low attenuation or peripherally enhancing (Fig. 10A, 10B). These imaging findings overlap with and must be differentiated from tuberculosis and other mycobacterial or fungal infections.


Figure 21
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Fig. 9 40-year-old woman with cervical cancer. Anteroposterior chest radiograph shows multiple micronodular opacities with some confluence in right upper lobe. Differential diagnosis includes mycobacterial and fungal infection. Biopsy revealed micronodular metastatic cervical cancer.

 

Figure 22
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Fig. 10A 53-year-old woman with HIV infection and metastatic cervical cancer. Axial contrast-enhanced chest CT scan shows low-attenuation, necrotic subcarinal and bilateral hilar lymphadenopathy. Differential diagnosis includes other causes of necrotic lymphadenopathy such as tuberculosis.

 

Figure 23
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Fig. 10B 53-year-old woman with HIV infection and metastatic cervical cancer. Axial contrast-enhanced CT scan of pelvis shows bulky primary mass arising from cervix and regional pelvic lymphadenopathy.

 
Laryngotracheal papillomatosis is usually contracted during vaginal delivery through aspiration of vaginal secretions and may also be sexually transmitted. Although the papillomatous lesions are benign, they may transform into squamous cell carcinoma.

Imaging features of laryngotracheal papillomatosis include irregular tracheobronchial nodules that are often numerous. The lesions can spread to the lung, resulting in lung nodes of varying sizes, often centrally located and cavitary. Pulmonary papillomas may undergo malignant transformation to squamous cell carcinoma (Fig. 11A, 11B, 11C, 11D).


Figure 24
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Fig. 11A 45-year-old man with HIV infection and long history of smoking who presented with persistent cough and difficulty breathing. Transbronchial biopsy and subsequent left lower lobectomy revealed tracheobronchial and pulmonary papillomatosis and multiple foci of invasive squamous cell carcinoma in lung. Posteroanterior chest radiograph shows multiple subtle irregularities of trachea (black arrows) and mainstem bronchi. Left lower lobe nodule (white arrow) is present.

 

Figure 25
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Fig. 11B 45-year-old man with HIV infection and long history of smoking who presented with persistent cough and difficulty breathing. Transbronchial biopsy and subsequent left lower lobectomy revealed tracheobronchial and pulmonary papillomatosis and multiple foci of invasive squamous cell carcinoma in lung. Chest CT scans show multiple irregular tracheobronchial nodules. Parenchymal nodules are also present, some with cavitation.

 

Figure 26
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Fig. 11C 45-year-old man with HIV infection and long history of smoking who presented with persistent cough and difficulty breathing. Transbronchial biopsy and subsequent left lower lobectomy revealed tracheobronchial and pulmonary papillomatosis and multiple foci of invasive squamous cell carcinoma in lung. Chest CT scans show multiple irregular tracheobronchial nodules. Parenchymal nodules are also present, some with cavitation.

 

Figure 27
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Fig. 11D 45-year-old man with HIV infection and long history of smoking who presented with persistent cough and difficulty breathing. Transbronchial biopsy and subsequent left lower lobectomy revealed tracheobronchial and pulmonary papillomatosis and multiple foci of invasive squamous cell carcinoma in lung. Chest CT scans show multiple irregular tracheobronchial nodules. Parenchymal nodules are also present, some with cavitation.

 
In conclusion, many HIV-related malignancies are strongly linked to infection with oncogenic viruses. Familiarity with the mode of transmission and imaging appearances should lead the radiologist to consider these neoplasms in the appropriate patient population.


References
Top
Abstract
Introduction
Human Herpesvirus 8
Epstein-Barr Virus
Human Papillomavirus
References
 

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  13. Herndier BG, Sanchez HC, Chang KL, Chen YY, Weiss LM. High prevalence of Epstein-Barr virus in the Reed-Sternberg cells of HIV-associated Hodgkin's disease. Am J Pathol 1993;142 :1073 –1079[Abstract]
  14. Frisch M, Biggar RJ, Engels EA, Goedert JJ. AIDS-Cancer Match Registry Study Group. Association of cancer with AIDS-related immunosuppression in adults. JAMA 2001;285 :1736 –1745[Abstract/Free Full Text]
  15. Sun XW, Kuhn L, Ellerbrock TV, Chiasson MA, Bush TJ, Wright TC. Human papillomavirus infection in women infected with the human immunodeficiency virus. N Engl J Med1997; 337:1343 –1349[Abstract/Free Full Text]

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