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Carcinoma sebáceo

Linhagem
  • Nas pálpebras → glândulas de Meibomian (sebáceas)
 
Clinical presentation
  • Ocular form
    • Ulcerated tumor unde the lower eyelid
    • Eyelid or caruncular tumor
    • Recurrent chalazion
    • Chronic unilateral blepharoconjunctivitis (if the tumor spreads pagetoid along the ciliary margin into the conjunctival epithelium)
  • Non-ocular form
    • Yellowish tumor nodule
    • Nipple-like plaque
    • Face, scalp, neck and more rarely the trunk or genitals
    • Treatment: wide excision
 
Associations
Muir-Torre Syndrome
Nevo/Hamartoma Sebáceo de Jadassohn
 
Histologia
  • large multilobulated tumors comprising and unorganized mixture of immature basal cells and sebaceous cells at various stages of maturation
  • Cells with low sebum content have microvacuolar cytoplasm with a central stellate nucleus
  • Mature cells contain only one or more large vacuoles with a displaced or pycnotic nucleus.
  • Malignancy is confirmed by foci of necrosis, nucleocytoplasmic atypia, images of pagetoid spread in the epidermis (particularly noticeable in eyelid locations) or vascular invasion
  • Immunohistochemisty
    • CK17
    • Androgen receptors
 
Histopathology diagnostic pearl
  • Immunohistochemistry should be performed on all sebaceous adenomas and carcinomas
  • 100% PPV: loss of MLH1 and MSH6; MSH2, MLH1, MSH6