Bacillary angiomatosis in patients with AIDS: multiorgan imaging findings

A comparison of Bartonella henselae infection in immunocompetent and immunocompromised mice

Bartonellosis refers to disease caused by the Bartonella genus of bacteria. The breadth of disease manifestations associated with Bartonella is currently expanding and includes regional lymphadenopathy, rheumatic, ocular, and neurological disorders. The dearth of knowledge regarding diagnosis, treatment and pathogenesis of this disease can be partially attributed to the lack of a reliable small animal model for the disease. For this study, Bartonella henselae, the most common species associated with human disease, was injected into Swiss Webster (SW) mice. When the outcome indicated that productive infection did not occur, SCID/Beige (immune compromised) mice were inoculated. While SW mice may potentially harbor an acute infection, less than 10 days in length, the SCID/Beige model provided a sustained infection lasting up to 30-days. These data indicate that SCID/Beige mice can provide a model to study Bartonella infection, therapeutics, and vector dynamics in the future.

Body Imaging of Bacterial and Parasitic Zoonoses: Keys to Diagnosis

Zoonotic infections, which are transmitted from animals to humans, have been a substantial source of human disease since antiquity. As the human population continues to grow and human influence on the planet expands, humans frequently encounter both domestic and wild animals. This has only increased as deforestation, urbanization, agriculture, habitat fragmentation, outdoor recreation, and international travel evolve in modern society, all of which have resulted in the emergence and reemergence of zoonotic infections. Zoonotic infections pose a diagnostic challenge because of their nonspecific clinical manifestations and the need for specialized testing procedures to confirm these diagnoses. Affected patients often undergo imaging during their evaluation, and a radiologist familiar with the specific and often subtle imaging patterns of these infections can add important clinical value. The authors review the multimodality thoracic, abdominal, and musculoskeletal imaging findings of zoonotic bacterial (eg, Bartonella henselae, Pasteurella multocida, Francisella tularensis, Coxiella burnetii, and Brucella species), spirochetal (eg, Leptospira species), and parasitic (eg, Echinococcus, Paragonimus, Toxocara, and Dirofilaria species) infections that are among the more commonly encountered zoonoses in the United States. Relevant clinical, epidemiologic, and pathophysiologic clues such as exposure history, occupational risk factors, and organism life cycles are also reviewed. Although many of the imaging findings of zoonotic infections overlap with those of nonzoonotic infections, granulomatous diseases, and malignancies, radiologists' familiarity with the imaging patterns can aid in the differential diagnosis in a patient with a suspected or unsuspected zoonotic infection. ^© RSNA, 2023 Quiz questions for this article are available through the Online Learning Center.

Vascular anomalies: diagnostic features and step-wise approach

The first part of this review article emphasized correct nomenclature, classification systems, and imaging algorithm of vascular anomalies. The second part of the review discusses the individual entities, highlighting the characteristic clinico-radiological features of the commonly encountered ones. A step-wise algorithmic approach is also proposed for the evaluation of a suspected case of vascular anomaly.

Pulmonary Kaposi's sarcoma in a female patient: Case report

Kaposi's sarcoma (KS) is a multicentric lymphoproliferative malignancy. Most of the time this tumor is confined to the skin and subcutaneous tissue, but it can present with widespread visceral involvement, such as in the lung. Pulmonary KS is the most frequent form in young adult males, in a ratio of 15:1. The disease usually affects individuals with low CD4 lymphocyte counts (<150-200 cells/mm3). We report a case of a female patient aged 35 years, with the presence of skin lesions, self-limiting episodes of diarrhea and weight loss of 15 kg for nearly 9 months, progressing to persistent fever. AIDS was diagnosed and biopsy of the lesions revealed Kaposi's sarcoma. Computed tomography of the chest showed peribronchovascular thickening, areas of ground glass opacity, condensations with air bronchograms surrounded by ground glass opacity (halo sign) and bilateral pleural effusion. The diagnosis of pulmonary KS is still a challenge, especially due to the occurrence of other opportunistic diseases that may also occur concurrently. Therefore, suspecting this diagnosis based on clinical and laboratory manifestations, and even more with CT findings, is fundamental, especially in patients who already have the cutaneous form of the disease.

Primary pulmonary meningioma: an unusual cause of a nodule with strong and homogeneous enhancement

We report a case of a 61-year-old female with atypical chest pain. The chest CT scan revealed a well-circumscribed large intrapulmonary nodule that showed vigorous and homogeneous contrast enhancement. The nodule was diagnosed as a meningioma after surgery. Metastatic meningioma was excluded by brain and spine MRI scans. Primary pulmonary meningioma usually appears as a solitary well-defined round or lobulated nodule with variable enhancement on CT; this case is unique because of the intense and homogeneous enhancement. Although rare, primary pulmonary meningioma should be considered in the differential diagnosis of a well-defined pulmonary nodule with dense and homogeneous enhancement.

Pulmonary nodules in an immunocompetent child with cat scratch disease

We describe an immunocompetent child with cat scratch disease and pulmonary nodules as part of her initial presentation. Although pulmonary manifestations have been reported with cat scratch disease, nodules are rare in the normal host.

What a differential a virus makes: a practical approach to thoracic imaging findings in the context of HIV infection--part 2, extrapulmonary findings, chronic lung disease, and immune reconstitution syndrome

OBJECTIVE

The Centers for Disease Control and Prevention reported more than one million people with HIV infection in the United States in 2006, an increase of 11% over 3 years. Worldwide, nearly 34 million people are infected with HIV. Pulmonary disease accounts for 30-40% of acute hospitalizations of HIV-seropositive patients, underscoring the importance of understanding the range of cardiothoracic imaging findings associated with HIV infection. This article will cover extrapulmonary thoracic diseases, chronic lung diseases, and immune reconstitution inflammatory syndrome in HIV-infected patients. Our approach is focused on the radiologist's perspective by recognizing and categorizing key imaging findings to generate a differential diagnosis. The differential diagnosis can be further refined by incorporating clinical data, such as patient demographics, CD4 count, and presenting symptoms. In addition, with prolonged survival of HIV-infected patients in the era of highly active antiretroviral therapy, radiologists can also benefit from awareness of imaging features of a myriad of chronic cardiopulmonary diseases in this patient population. Finally, the change of imaging findings and clinical status in response to treatment provides important diagnostic information, such as in immune reconstitution syndrome.

CONCLUSION

Developing a practical approach to key cardiothoracic imaging findings in HIV-infected patients will aid the radiologist in generating a clinically relevant differential diagnosis and interpretation, thereby improving patient care.

Imaging manifestations of neck masses in the immunocompromised host

Human immunodeficiency virus (HIV) infection, haematological malignancy, and immunosuppression for transplantation and autoimmune disorders have led to a large increase in immunocompromised patients. Neck masses are relatively common in this patient group and include both opportunistic and severe manifestations of common infections, benign hyperplasia, and primary or secondary malignancies. Although biopsy may be necessary for definitive diagnosis, features on cross-sectional imaging may suggest a specific diagnosis or limit the differential diagnosis and facilitate optimal patient management. This article will review critical aspects of neck anatomy, illustrate the spectrum of imaging features, and discuss the interpretative pearls and pitfalls when evaluating neck masses in immunocompromised patients.

Imaging Manifestations of Kaposi Sarcoma

Kaposi sarcoma (KS) is a low-grade vascular tumor that typically manifests as one of four variants: classic KS, endemic (African) KS, iatrogenic (organ transplant-related) KS, or acquired immunodeficiency syndrome (AIDS)-related KS. Several clinical and epidemiologic differences have been noted among these variants. Classic KS and endemic KS rarely require radiologic evaluation due to their usually chronic course and stability of skin compromise. However, iatrogenic KS and AIDS-related KS, the most common forms of the disease, are frequently disseminated or symptomatic and may thus require imaging studies for both diagnosis and staging. KS is the most common tumor among AIDS patients, affecting a high percentage of these individuals, and is considered to be an AIDS-defining illness. Multiple organs can be involved by AIDS-related KS. KS has been linked with human herpes virus type 8 infection and other cofactors. Although pulmonary, gastrointestinal, and skin involvement by KS has previously been described, this tumor can affect multiple organs, generating a wide spectrum of imaging findings and pathologic correlates. It is important for the radiologist to be familiar with this spectrum of imaging manifestations and corresponding pathologic findings.

The infected liver: radiologic-pathologic correlation

Recent technologic advances have significantly enhanced the role of imaging in the detection, characterization, and management of infectious diseases involving the liver. In addition, imaging-guided percutaneous drainage has greatly improved the clinical treatment of patients with focal liver abscess. Infectious liver diseases can be accurately evaluated with ultrasonography (US), computed tomography (CT), and magnetic resonance (MR) imaging. Characteristic changes in US echogenicity, CT attenuation, or MR imaging signal intensity and typical enhancement patterns can contribute to the diagnosis of specific infectious diseases, including abscesses, parasitic diseases, fungal diseases, granulomatous diseases, viral hepatitis, and other less common infections. CT is particularly helpful in revealing the presence of calcifications and gas and in detailing the enhancement pattern. The multiplanar capability of MR imaging and its sensitivity to small differences in tissue composition increase its specificity for certain hepatic infections, including hydatid cyst and candidiasis. Radiologic findings may be sufficient to obviate aspiration or histologic examination, although in most instances they are less specific. Nevertheless, imaging findings taken together with appropriate clinical information may provide the most likely diagnosis, even if biopsy is sometimes required for confirmation.

Radiologic approach to the diagnosis of infectious pulmonary diseases in patients infected with the human immunodeficiency virus

Nearly all patients infected with HIV experience respiratory infection at some point in the course of their illness. The spectrum of infections is varied and in order to generate a useful differential diagnosis based on imaging findings it is imperative for the radiologist to be aware of changing trends in disease prevalence and epidemiology, and the possible pathology related to new therapies. The characterization of the radiographic pattern in correlation with clinical findings and laboratory values (in particular the degree of immunosuppression as reflected in the CD4 level) would be helpful in narrowing the differential diagnosis of infectious pulmonary disease in HIV-positive patients. The most common radiologic patterns considered include areas of ground-glass, consolidation, nodules, and lymphadenopathy. We also include airways diseases and cavitary/cystic lesions because their prevalence has increased over recent years, and we also mention the significance of a normal chest radiograph in the suspicion of a lung infection. In most cases, the clinical and radiographic findings are sufficient for confident diagnosis. The radiologic diagnosis of thoracic infections in patients with AIDS has improved with the use of CT. The greatest value of CT is in excluding lung disease when the radiographic findings are equivocal and in confirming the presence of clinically suspected disease when the radiograph is normal.

Imaging features of bacterial respiratory infections in AIDS

PURPOSE OF REVIEW

Although an emphasis has historically been placed on nonbacterial, opportunistic respiratory infections in HIV-infected individuals, it is increasingly important for clinicians to be familiar with the spectrum of bacterial respiratory infections that may occur in this population.

RECENT FINDINGS

Bacterial pneumonia and acute bronchitis are currently the most common causes of respiratory disease in HIV-infected individuals in developed countries. Moreover, these infections are frequently the first clinical manifestation of HIV infection. Among patients with sustained CD4 cell count >200 cells/microL, the discontinuation of Pneumocystis carinii pneumonia prophylaxis is not associated with an increased risk of bacterial pneumonia. The most common radiographic pattern of bacterial pneumonia is focal consolidation, which typically presents in either a segmental or lobar distribution. In cases in which the chest radiograph is inconclusive, high-resolution chest CT has a very high accuracy for detecting pyogenic small airways disease and for distinguishing between P. carinii pneumonia and other lung infections including bacterial infection.

SUMMARY

Knowledge of the characteristic imaging and clinical features of bacterial respiratory infections can enhance their timely diagnosis and treatment.

Otolaryngologic manifestations of human immunodeficiency virus infection

The otolaryngologist is uniquely positioned to detect and pursue manifestations of HIV in the head and neck. The presentation of problems subsequent to HIV infection is quite varied, but close investigation will often reveal treatable problems.

Update on lung disease in AIDS

Pulmonary disorders remain an important complication of HIV infection, even in the current era of potent antiretroviral therapy. Using an integrated approach that combines radiographic pattern recognition with knowledge of a patient's clinical symptoms, laboratory data, immune status level, demographic information, and drug therapy can enhance the interpretation of imaging studies in HIV-infected patients. Although chest radiography remains the mainstay of imaging the HIV-positive patient with respiratory symptoms, CT plays an increasingly important secondary role in selected cases.

Bacillary angiomatosis: description of 13 cases reported in five reference centers for AIDS treatment in Rio de Janeiro, Brazil

The aim of this case series was to describe the clinical, laboratory and epidemiological characteristics and the presentation of bacillary angiomatosis cases (and/or parenchymal bacillary peliosis) that were identified in five public hospitals of Rio de Janeiro state between 1990 and 1997; these cases were compared with those previously described in the medical literature. Thirteen case-patients were enrolled in the study; the median age was 39 years and all patients were male. All patients were human immunodeficiency virus type 1 (HIV-1) infected and they had previous or concomitant HIV-associated opportunistic infections or malignancies diagnosed at the time bacillary angiomatosis was diagnosed. Median T4 helper lymphocyte counts of patients was 96 cells per mm(3). Cutaneous involvement was the most common clinical manifestation of bacillary angiomatosis in this study. Clinical remission following appropriate treatment was more common in our case series than that reported in the medical literature, while the incidence of relapse was similar. The frequency of bacillary angiomatosis in HIV patients calculated from two of the hospitals included in our study was 1.42 cases per 1000 patients, similar to the frequencies reported in the medical literature. Bacillary angiomatosis is an unusual opportunistic pathogen in our setting.

Multimodality demonstration of primary splenic angiosarcoma

Angiosarcomas are rare, accounting for only 1-2% of all soft tissue sarcomas. Primary abdominal angiosarcomas usually arise in the liver or spleen. We report the first color Doppler findings of a rare, low-grade splenic angiosarcoma in a 52-year-old woman.

Bacillary angiomatosis in immunocompromised patients

OBJECTIVES

To report seven cases of bacillary angiomatosis; to evaluate the most useful diagnostic tools; to analyse the clinical and epidemiological features associated with Bartonella quintana or Bartonella henselae infections.

DESIGN

Clinical, diagnostic and epidemiological evaluation of 37 speciated bacillary angiomatosis cases in the literature, including the seven patients in our study.

METHODS

Pathological examination of tissue samples, including Warthin-Starry staining and immunohistology; titre of antibodies to Bartonella sp.; detection of Bartonella sp. in blood and biopsy materials by culture or PCR; and statistical analysis of clinical and epidemiological features associated with B. quintana or B. henselae bacillary angiomatosis cases.

RESULTS

Seven immunocompromised patients (six with AIDS and one patient with acute leukaemia) had bacillary angiomatosis confirmed by histology. B. quintana was cultured in three patients, whereas B. henselae DNA was amplified by PCR in the remaining four patients. Serum from only one patient reacted with Bartonella antigens. Amongst the 14 B. quintana and 23 B. henselae bacillary angiomatosis cases now reported in the literature, lymphadenopathies were significantly more frequent in B. henselae-infected patients, and neurological disorders of the central nervous system in B. quintana-infected patients. Risk factors were contact with cats, and homelessness or poor socioeconomic status in B. henselae and B. quintana bacillary angiomatosis cases, respectively.

CONCLUSIONS

Although diagnosis of bacillary angiomatosis often remains solely based upon histology, culture or PCR-based methods are useful for the detection of Bartonella sp., and allow identification of the species involved, which is necessary to further characterize clinical and epidemiological features associated with B. quintana or B. henselae infections.

CT manifestations of human immunodeficiency virus (HIV)-related pulmonary infections

The infectious pulmonary complications of acquired immunodeficiency syndrome (AIDS) are reviewed, with emphasis on the spectrum of CT imaging findings and diagnostic accuracy and limitations as reported in the current literature. Changes in epidemiologic trends for common AIDS-related infections and the associated ranges of CD4 lymphocyte counts, when these infections are typically encountered, are discussed.

Acquired immunodeficiency syndrome (AIDS) of the abdominal organs: imaging features

The liver, spleen, biliary tract, pancreas, and kidneys are commonly affected by opportunistic infection, malignancy, and inflammatory disorders during the course of human immunodeficiency virus (HIV) infection. Clinical manifestations of solid abdominal visceral involvement are protean and usually nonspecific, but it is important to establish a specific diagnosis promptly in these often critically ill patients. This presentation reviews the cross-sectional imaging spectrum of HIV-associated lesions of these organs.

Bacillary angiomatosis in an HIV seronegative patient on systemic steroid therapy

Bacillary angiomatosis is an unusual systemic vascular proliferation seen predominantly in patients with the acquired immunodeficiency syndrome. These vascular lesions are due to infection with a Bartonella species, most commonly B. henselae, but sometimes B. quintana. It is treatable and often curable, but without therapy may be life-threatening. Clinically, the disorder often resembles several different vascular disorders, particularly pyogenic granuloma and Kaposi's sarcoma. We now report a clinically typical patient with bacillary angiomatosis who was HIV seronegative, but who had idiopathic thrombocytopenic purpura, was status-post splenectomy and to whom long-term systemic prednisone had been administered.