Table of Contents
Definition / general | Case reports | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Cytology images | Positive stains | Negative stains | Molecular / cytogenetics description | Differential diagnosis | Additional referencesCite this page: DePond WD. Kaposi sarcoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/lymphnodesks.html. Accessed January 17th, 2021.
Definition / general
- Difficult to detect early involvement; often best diagnosis is atypical vascular proliferation suggestive of early Kaposi sarcoma
- May coexist with leukemia, lymphoma, Castleman disease or mycobacterial spindle cell tumor (Am J Surg Pathol 1999;23:656)
- Classic form: elderly men of Jewish or Mediterranean descent; skin lesions of lower extremities with only rare nodal involvement; indolent for 10 - 15 years, then systemic lesions or lymphoreticular malignancies
- African (endemic) form: young adults, usually men with indolent skin involvement, progressive large exophytic or deeply invasive tumors or occasional regional nodal involvement
- Childhood form: children 2 - 13 years, usually boys, HIV negative with lymphadenopathy but usually no skin lesions; death within 1 - 3 years
- HIV associated: usually homosexual men, often disseminated involving mucocutaneous sites, lymph nodes, GI tract and lungs
- Transplant associated: local or systemic (Transplant Proc 2004;36:2145, Transplant Proc 2005;37:967)
Case reports
- 58 year old man with intraparotid lymph node (Laryngoscope 2005;115:861)
- 65 year old man with history of colon cancer presented with a 2.5 cm groin node (Case of the Week #307)
Gross description
- Often multifocal
Microscopic (histologic) description
- Resembles skin tumors
- Curved fascicles of spindle cells separated by slit-like vascular spaces with extravasated red blood cells and frequent mitotic figures
- Spindle cells have pale cytoplasm, elongated nuclei, indistinct nucleoli; often individual cell necrosis
- Initially subcapsular but extends throughout node and into perinodal tissue
- Almost always has PAS+ diastase resistant, PTAH+ hyaline globules
- May have accompanying lymphocytes, plasma cells, histiocytes and immunoblasts, hemosiderin deposits
- May resemble Castleman disease
Microscopic (histologic) images
Case #307
CD31
HHV8
Cytology images
Case #307
Various images
Negative stains
Molecular / cytogenetics description
- HHV8+ (strong, diffuse, nuclear staining in > 10% of tumor cells, Mod Pathol 2004;17:456)
Differential diagnosis
Additional references
