Other malignancies
Kaposi sarcoma

Topic Completed: 2 September 2013

Minor changes: 12 December 2019

Copyright: 2003-2019,, Inc.

PubMed Search: Kaposi sarcoma esophagus

Feriyl Bhaijee, M.D.
Israh Akhtar, M.D.
Page views in 2019: 591
Page views in 2020 to date: 306
Cite this page: Akhtar I, Bhaijee F. Kaposi sarcoma. website. Accessed July 4th, 2020.
Definition / general
  • Uncommon, low grade, vascular malignancy caused by Kaposi sarcoma herpesvirus / human herpesvirus 8 (KSHV / HHV8) infection (Arch Pathol Lab Med 2013;137:289)
  • See also soft tissue chapter
  • 4 distinct clinical settings:
    • Classic (Mediterranean) Kaposi sarcoma (KS)
    • Endemic (African) KS
      • Adults and children in equatorial Africa
      • Skin lesions involving lower extremities or lymph nodes
      • Lymphadenopathic form is aggressive
    • AIDS associated (epidemic) KS
      • AIDS defining illness in HIV+ adults / children
      • Disseminated mucocutaneous / visceral lesions
      • Aggressive
      • May regress or flare with HAART
    • Iatrogenic KS
      • Immunosuppressed patients (autoimmune disease, drugs, posttransplant)
      • Localized or disseminated disease
      • Variable outcome
  • More common in males, immunocompromised patients, especially HIV+ or posttransplant
    • KS is most common AIDS related malignancy
  • Associated with chronic lymphedema, posttraumatic sites (Koebner phenomenon)
  • Mucocutaneous > visceral
  • Usually submucosal, multicentric
  • Lymphatic endothelial origin, due to HHV8 infection
    • HHV8 encoded latency associated nuclear antigen (LANA1) is immunodominant oncoprotein which promotes cellular transformation and viral oncogenesis
    • Lymphatic associated genes are upregulated in endothelial cells, including lymphatic vessel endothelial receptor 1 (LYVE1), podoplanin (D2-40), vascular endothelial growth factor receptor 3 (VEGF3)
    • However, HHV8 seropositivity >> KS incidence
    • Other cofactors include host immune dysfunction, local inflammatory milieu
  • HIV infection augments HHV8 replication
Clinical features
  • HIV testing recommended for patients with biopsy proven KS
Radiology description
  • Minimally elevated submucosal lesions
  • Polypoid defects
  • Air contrast esophagogram shows 2 cm smooth filling defect (Radiographics 2006;26:465)
Prognostic factors
  • Disseminated KS is often fatal
  • AIDS related and African KS are more aggressive than Mediterranean KS
  • Iatrogenic KS may regress when immunosuppression is discontinued
Case reports
  • Mainly palliative, based on extent of disease:
    • Local / mucocutaneous:
      • External beam radiation, laser therapy, cryotherapy, photodynamic therapy
      • Topical alitretoin gel, topical immunotherapy (imiquimod), intralesional chemotherapy (vinblastine), surgical excision
    • Systemic / disseminated / visceral:
      • IV chemo / immunotherapy (e.g. liposomal anthracyclines and taxanes), interferon alpha, HAART if HIV+
      • Modification of immunosuppression if posttransplant
      • Antivirals not effective because tumor cells harbor latent (not lytic phase) HHV8
Clinical images

Images hosted on other servers:

Raised, reddish purple nodules

Dark red mucosal patch

Gross description
  • Violaceous patches, plaques, papules or nodules
  • Variable ulceration, lymphedema, invasion of underlying tissues
Microscopic (histologic) description
  • Submucosal spindle cell proliferation with intervening slit-like spaces
    • Often obliterates the muscularis mucosae
    • Slit-like spaces contain erythrocytes
    • Eosinophilic PAS+ hyaline bodies in tumor cells or extracellular
    • Usually no pleomorphism, necrosis or mitotic activity
  • Extravasated erythrocytes, hemosiderin laden macrophages
  • Variable chronic inflammatory cell infiltrate
  • Newer histologic variants: anaplastic, bullous, ecchymotic, glomeruloid, hyperkeratotic, intravascular, keloidal, lymphangioma-like, micronodular, pigmented, pyogenic granuloma-like, telangiectatic, with myoid nodules, with sarcoid-like granulomas
  • Variants have unknown clinical significance (Arch Pathol Lab Med 2013;137:289)
Microscopic (histologic) images

Images hosted on other servers:

Various images

Small bowel

Positive stains
Negative stains
Electron microscopy description
  • Tumor cells contain occasional Weibel-Palade bodies and fragmented erythrocytes
Molecular / cytogenetics description
  • HHV8 can be detected by PCR
Differential diagnosis
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