Archived case 216 · February 13-February 20, 2017
IRIS-mediated progression of Kaposi’s Sarcoma
33 y/o male HIV/AIDS recent HAART initiation and significantly worsening findings on CT
The question posed to readers
Scans provided are 2 months apart
Images
Imaging findings
Axial and coronal CT images taken 2 months apart demonstrate significant interval progression of bilateral flame-shaped and ill-defined nodules, most of which are seen in a perilymphatic distribution. Groundglass opacities with interlobular septal thickening has developed in the right middle lobe and there has also been rapid enlargement of subcarinal and hilar lymph nodes. Answer Diagnosis: IRIS-mediated progression of Kaposi’s Sarcoma
Diagnosis
IRIS-mediated progression of Kaposi’s Sarcoma
Immune reconstitution inflammatory syndrome (IRIS) is paradoxical deterioration of an AIDS related illness following initiation of highly active anti-retroviral therapy (HAART) or post treatment of autoimmune disease such as multiple sclerosis. It has been associated with pathogens including TB, PML, Cryptococcus, and Kaposi’s sarcoma.
It has been reported to affect 10-25% of patients with AIDS. Patients at highest risk are those with low CD4+ count and high plasma HIV RNA prior to initiation of therapy, rapid decrease in CD4+ count or HIV RNA following initiation of therapy, and initiation of HAART soon after diagnosis of an opportunistic infection.
Symptoms typically develop within 60 days following initiation of HAART and generally mimic worsening of the underlying condition, despite rising CD4 counts and a falling viral load.
The imaging features are widespread either reflecting the imaging appearances of the underlying pathogen or may mimic worsening of the underlying condition, or be atypical. Typically enhancing masses gain mass effect rapidly. Enhancement is variable and may appear bizarre or wild.
In this case of a patient with known metastatic Kaposi’s sarcoma, there was significant progression of ill-defined, flame shaped nodules and confluent peribronchovascular opacities centered in both hilar regions. There was also development of RML groundglass opacities and worsening mediastinal adenopathy, both features of Kaposi’s thoracic involvement.
Treatment for IRIS is steroid therapy with continuation of HAART. IRIS itself is not typically fatal, with fatality rates estimated at under 5%.
1. Chen KC, Chen JY, Tung GA. Case 149: Immune reconstitution inflammatory syndrome. Radiology. 2009;252 (3): 924-8. doi:10.1148/radiol.2523080402 - Pubmed citation
2. Godoy MC, Rouse H, Brown JA et-al. Imaging features of pulmonary Kaposi sarcoma-associated immune reconstitution syndrome. AJR Am J Roentgenol. 2007;189 (4): 956-65. doi:10.2214/AJR.07.2458 - Pubmed citation
Original case written by its authors at Virginia Commonwealth University and published at this address as part of a weekly teaching collection. Reproduced here as an archive.