CASE 14306 Published on 08.12.2016

Thoracic Kaposi Sarcoma

Section

Cardiovascular

Case Type

Clinical Cases

Authors

Sampaio-Macedo, C. (1), Araújo, J. (1), Ricardo M. (2), Oliveira, J. (1), Louro, J. (1), Teixeira-Gomes M. (1), Rocha-Neves, J. (3)

(1) Radiology Department, (2) Internal Medicine Department, Centro Hospitalar do Porto; (3) Centro Hospitalar São João Portugal; Email:cssampaiomacedo@gmail.com
Patient

28 years, female

Categories
Area of Interest Thorax, Mediastinum ; Imaging Technique Conventional radiography, CT-High Resolution, CT
Clinical History
A 28-year-old female patient, with a history of over a decade of HIV infection (CD4-cell count 98 cells µ/L), presented with a 6-week history of progressive dyspnoea upon exertion, accompanied by productive cough of yellow sputum. She was previously medicated with antibiotics for bacterial pneumonia.
Imaging Findings
Chest radiograph showed an irregular right hilar consolidation, first thought to correspond to bacterial pneumonia (Fig 1). Despite undergoing antibiotic treatment, the patient's symptoms progressed. The subsequent CT showed a right peribronchovascular consolidation with flame-shaped hilar radiation, and poorly defined lung nodules, which first raised the suspicion of KS (Fig 2-4).
Bronchoscopy revealed diffusely hyperemic, swollen mucosa of the lower airways with mucopurulent secretions. Bronchoalveolar lavage PCR for HHV-8 showed 5600 DNA copies/mL. Transbronchial biopsy was done and pathology was positive for KS.
This case demonstrates the classic imaging features of pulmonary Kaposi Sarcoma. Interestingly, this diagnosis was made in the absence of the typical skin manifestations of the disease. Her disease was complicated by progressive respiratory failure and she eventually died.
Discussion
Kaposi Sarcoma (KS) is a low-grade angioproliferative tumour associated with human herpes virus 8 (HHV-8) [2] and is the most common AIDS defining malignancy worldwide [1]. Nonetheless, in the era of Highly Active Antiretroviral Therapy, the incidence of KS has declined.
At the time of diagnosis most patients with lung KS have previously treated cutaneous lesions or other visceral involvement. Nonetheless, cutaneous involvement is absent in 5–23% of patients with symptomatic pulmonary KS. Manifestations include parenchymal, tracheal, lymphatic, pleural and chest wall abnormalities. Common clinical symptoms include dry chronic cough, dyspnoea, fever, and hemoptysis.
The bronchoscopic appearance is considered characteristic to make a presumptive diagnosis (red or purplish stained lesions).
At radiography, AIDS-related KS may manifest as an isolated finding or in association with an opportunistic infection, further delaying and confusing the diagnosis. Radiography may demonstrate middle to lower lung zone reticular opacities and parenchymal nodules with a peribronchovascular distribution that may progress to consolidation, peribronchial cuffing, pleural effusions, and hilar or mediastinal adenopathies. When fever is present, sometimes it cannot be distinguished from superimposed infection at radiography.
CT scans have more specificity and sensitivity, and can demonstrate characteristic finding such as the presence of unilateral or bilateral ill-defined nodules, involving the peribronchovascular sheaths, often beginning in the peri-hilar regions and extending to the periphery, so called flame-shaped lesions [3]. Other findings include interlobular septal thickening, usually preserving the lobular architecture and simulating carcinomatous lymphangitis; large parenchymal nodules with irregular, poorly defined, and spiculated borders, some of them with a perinodular ground glass halo sign [2]. Other less common findings include asymmetrically distributed nodules and larger masses. Osseous and soft-tissue involvement such as lytic lesions of the sternum, ribs and the spine and soft-tissue masses are seen in up to 53% of cases.
The differential diagnosis includes lymphoma, bronchogenic carcinoma, infection, and bacillary angiomatosis. A diagnosis of mycobacterial or bacterial infection is favoured by the presence of a tree-in-bud pattern or subcentimeter nodules with a centrilobular distribution. P. jiroveci pneumonia does not usually manifest with hilar adenopathies or pleural effusion but may exhibit cavitation. Nodule size is not helpful in differentiating KS from lymphoma or bronchogenic carcinoma, and biopsy may be necessary. Bacillary angiomatosis may mimic AIDS-related KS, with violaceous plaques at bronchoscopy, solitary or multiple pulmonary nodules, and mediastinal lymphadenopathies that demonstrate intense enhancement at contrast-enhanced CT [3].
Differential Diagnosis List
Kaposi Sarcoma
Kaposi Sarcoma
Pulmonary infection
Final Diagnosis
Kaposi Sarcoma
Case information
URL: https://www.eurorad.org/case/14306
DOI: 10.1594/EURORAD/CASE.14306
ISSN: 1563-4086
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