Multifocal hypodense nodules or masses on CECT with delayed enhancement
• Gastrointestinal
50% of patients with cutaneous Kaposi sarcoma (KS) will have GI tract involvement
Upper GI tract (especially stomach and duodenum) most common, but can affect any part of GI tract
Submucosal nodules or polypoid masses (< 3 cm) most common, although larger infiltrative masses possible
Regional enhancing lymphadenopathy common
Lesions may cause intussusception or obstruction
Submucosal nodules on barium studies with ulceration may appear as “target” or bull’s-eye lesions
• Lymphadenopathy
Most commonly involves retroperitoneal lymph nodes
Commonly hypervascular/avidly enhancing
TOP DIFFERENTIAL DIAGNOSES
• Lymphoma
• Hepatic opportunistic infections
• Intestinal opportunistic infections
• Other causes of hypervascular lymphadenopathy
Hypervascular lymph node metastases
Castleman disease
• Other causes of multiple hepatic/splenic nodules
Metastatic disease from other malignancies
Sarcoid
Hepatic microabscesses or fungal infection
PATHOLOGY
• Associated with human herpesvirus type 8 (HHV8) infection and variable cofactors
• 4 clinical subtypes of KS
Classic (sporadic) KS: Affects elderly men of Eastern European or Mediterranean origin with visceral involvement uncommon
– Indolent cutaneous involvement of lower extremities
Endemic (African) KS: Not associated with HIV, and accounts for up to 1/2 of all cancers in parts of Africa
Iatrogenic (organ transplant-related) KS: Typically develops 1-2 years after transplant, with visceral involvement more likely with heart and liver transplants
Epidemic (AIDS-related) KS: ↓ prevalence with antiretroviral therapies
(Left) Axial CECT in a patient with AIDS and disseminated Kaposi sarcoma (KS) shows widespread thoracic lymphadenopathy. Many of the lymph nodes demonstrate hypervascularity , characteristic of KS.
(Right) Axial CECT in the same patient shows widespread abdominal lymphadenopathy with hyperenhancing lymph nodes that help to distinguish KS from lymphoma or other causes of lymphadenopathy.
(Left) Axial CECT through the pelvis in an AIDS patient shows widespread avidly enhancing adenopathy . On excisional biopsy, there was histologic evidence of Castleman disease and KS, both of which can present with avidly enhancing lymph nodes.
(Right) Axial CECT in a patient with HIV and KS shows widespread lymphadenopathy, including nodes in the groin that show hyperenhancement. This patient complained of marked edema of the lower extremities, a common symptom of KS-induced inguinal lymphadenopathy.
TERMINOLOGY
Abbreviations
• Kaposi sarcoma (KS)
Definitions
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Classic (sporadic) KS: Affects elderly men of Eastern European or Mediterranean origin with visceral involvement uncommon
Endemic (African) KS: Not associated with HIV, and accounts for up to 1/2 of all cancers in parts of Africa
, characteristic of KS.
with hyperenhancing lymph nodes that help to distinguish KS from lymphoma or other causes of lymphadenopathy.
. On excisional biopsy, there was histologic evidence of Castleman disease and KS, both of which can present with avidly enhancing lymph nodes.
that show hyperenhancement. This patient complained of marked edema of the lower extremities, a common symptom of KS-induced inguinal lymphadenopathy.
