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proliferating trichilemmal tumor

Friday 7 December 2012


- proliferating trichilemmal tumor can mimic squamous cell carcinoma (SCC), especially on small biopsy from the scalp


- proliferating trichilemmal tumor
- proliferating trichilemmal cyst

proliferating trichilemmal cyst


- microscopy

  • Proliferating trichilemmal cysts grow rapidly and may also arise de novo.
  • Although biologically benign, they may be locally aggressive, becoming large and ulcerated.
  • Rarely, malignant transformation leads to distant metastases.
  • No absolute clinical criteria can distinguish malignant from benign proliferating pilar tumors.
  • The entire lesion must undergo histological evaluation to assess for malignancy.
  • Atypia and a high mitotic rate are suggestive of malignancy.

See also

- trichilemmal cyst