Penis and scrotum
Other malignancies
Kaposi sarcoma

Authors: Antonio Cubilla, M.D., Alcides Chaux, M.D. (see Authors page)

Revised: 23 August 2018, last major update May 2010

Copyright: (c) 2002-2018, PathologyOutlines.com, Inc.

PubMed Search: Kaposi sarcoma penis

Cite this page: Cubilla, A., Chaux, A. Kaposi sarcoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/penscrotumkaposi.html. Accessed October 15th, 2018.
Definition / general
  • Low grade vascular tumor caused by human herpesvirus 8 (HHV8), also called Kaposi sarcoma associated herpesvirus (KSHV) and usually associated with HIV (Diagn Pathol 2008;3:31)
  • ICD-O: 9140 / 3
Epidemiology
  • Classic: affects elderly men of Mediterranean origin and Ashkenazi Jews; presents as indolent disease with nodular lesions on skin, affecting more often the lower limbs and feet and rarely with visceral involvement
  • Endemic: young men in sub-Saharan Africa, more aggressive, affects skin extensively, particularly lower limbs; NOT related to HIV
  • Transplant related: more prominent after use of cyclosporine for transplant patients
  • Epidemic: associated with AIDS or less commonly other immunosuppressed states; patients younger than with other sarcomas
Sites
  • Affects distal penis, mainly glans and coronal sulcus but also foreskin and penile shaft
Etiology
  • HHV8 / KSHV detected in most cases
  • Unclear whether it represents a true neoplasm or a reactive condition
Clinical features
  • Most common sarcoma of penis
  • Blue-purple to erythematous lesions
  • Frequently multicentric
  • May present in any of its typical stages (patch, plaque or nodular)
Case reports
Treatment
  • Treatment for HIV (HAART); also local excision, cryotherapy, laser therapy or radiation therapy
  • Also interferon alpha or chemotherapeutic drugs
Clinical images

Images hosted on PathOut server:

42 year old
homosexual with
ulcerated plaque
in coronal sulcus

36 year old HIV+
man with extensive
involvement of glans
causing meatal stricture

Tumor forms discrete nodules

Gross description
  • Usually multiple, small, 2 - 6 mm bluish lesions in glans
Microscopic (histologic) description
Patch stage:
  • Subtle proliferation of jagged vessels separating collagen bundles
  • Promontory sign: adnexal structures and preexisting vessels protruding into newly formed vessels
  • Extravasated erythrocytes and hemosiderin laden macrophages
  • Patchy inflammatory infiltrate composed of lymphocytes and plasma cells

Plaque stage:
  • Vascular proliferation is more evident
  • Bland spindle cells appear between vessels
  • Intra and extracellular PAS+ hyaline globules
  • Autolumination: paranuclear vacuoles containing erythrocytes

Nodular stage:
  • Spindle cells merge to form well defined nodules
  • Absence of significant nuclear atypia
  • Slit-like vascular spaces with numerous erythrocytes
  • Intracytoplasmic grape-like clusters of PAS+ diastase resistant hyaline globules
  • Prominent lymphoplasmacytic inflammatory infiltrate
Microscopic (histologic) images

Images hosted on PathOut server:

Low power

High power; note the slit-like blood vessels



Images hosted on other servers:

Other sites:

Patch stage; with promontory sign (right)

Plaque stage

Nodular stage

Resembles cavernous hemangioma


CD31+

CD34+

Lymphangioma-like variant

Lymphangiectactic variant


Bullous variant

Telangiectatic variant; CD31+ (right)

Hyperkeratotic (verrucous) variant

Hyperkeratotic and lymphangioma-like features

Keloidal variant


Micronodular variant

Pyogenic granuloma-like variant

Ecchymotic variant

Regressed lesion

Negative stains
Differential diagnosis