Benign tumors / changes
Clear cell "sugar" tumor of breast

Author: Monika Roychowdhury, M.D. (see Authors page)

Revised: 18 January 2017, last major update January 2017

Copyright: (c) 2003-2017,, Inc.

PubMed Search: Clear cell "sugar" tumor of breast

Cite this page: Benign tumors / changes - Clear cell . website. Accessed March 28th, 2017.
Definition / General
  • Very rare tumor in breast of epithelioid to spindle cells with clear to eosinophilic granular cytoplasm and distinct cell borders, positive for melanocytic markers
Essential Features
  • Rare tumor differentiating towards Perivascular Epithelioid Cells
  • Belongs to PEComa family of tumors, extremely rare in breast
  • Microscopy shows spindle to epithelioid cells with clear or eosinophilic cytoplasm and distinct cell borders
  • Stains positive for melanocytic markers
  • Treatment by excision; new drug rapamycin under investigation
Clinical Features
  • Benign behavior
Case Reports
  • Excision
  • Trial with rapamycin in progress; may become useful for malignant cases
Micro Description
  • Epithelioid to spindle cells with clear cytoplasm and distinct cell borders
Micro Images
Images hosted on other servers:

Clear cell "sugar" tumor - lung

Lung tumor is HMB45+

Positive Stains
Negative Stains
Molecular / Cytogenetics Description
  • Related to the genetic alterations of tuberous sclerosis complex, an autosomal dominant disease due to loss of TSC1 (9q34) or TSC2 (16p13.3) genes which seem to have a role in regulation of the Rheb/Mtor/p70S6K pathway
Differential Diagnosis
  • Glycogen rich (clear cell) carcinoma: large nests of clear cells with hyperchromatic nuclei, mild / moderate atypia and pleomorphism; invasive; keratin+, PAS+ diastase sensitive; negative for HMB45 and MelanA
Additional References