Pilomatricoma

From Libre Pathology
Jump to navigation Jump to search

Pilomatricoma is a benign skin lesion that is common in childhood. It may be spelled pilomatrixoma.

Pilomatricoma
Diagnosis in short

Pilomatricoma. H&E stain.

LM "ghost" cells, foreign body-type giant cells
LM DDx squamous cell carcinoma, pilomatrix carcinoma, basal cell carcinoma, epidermal inclusion cyst, heterotopic ossification
Gross skin nodule, hard
Site skin

Clinical history common in children
Signs hard nodule
Symptoms +/-painful
Prevalence common
Prognosis benign
Clin. DDx surgical excision

It is also known as calcifying epithelioma of Malherbe.[1]

General

  • Benign skin tumour.
  • Most common solid skin tumour of children.[2]
  • CTNNB1 gene mutation important in pathogenesis.[3]

Clinical:

  • Hard nodule - calcification.
  • +/-Painful.

Treatment:

  • Surgical excision.[2]

Microscopic

Features:[4]

  • Nodular circumscribed lower dermis/subcutaneous adipose lesion; thus, usu. surrounded by connective tissue.
    • Sharpy demarcated island of cells.
    • Calcification in 75%.
  • Cells:[5]
    • Basaloid epithelial cells - have prominent nucleoli.
    • Anucleate squamous cells ("ghost cells").
    • Giant cell foreign body type granulomas (form in reaction to keratin).

Notes:

  • Keratin a prominent feature on cytology - lots of orange stuff.
  • May (extensively) ossify.[6]

DDx:

Images

www:

Sign out

Skin Lesion, Left Forearm, Excision:
- Pilomatricoma with ossification.

Block letters

SKIN LESION, RIGHT ARM, EXCISION:
- PILOMATRICOMA.

Micro

The sections show anucleate squamous cells ("ghost cells") and multinucleated giant cells. No calcification is present. No significant nuclear atypia is present. No mitotic activity is apparent. There is also mildly inflamed fibroadipose tissue and some benign squamous mucosa.

Alternate

The sections show anucleate squamous cells ("ghost cells") and multinucleated giant cells. Calcification is present. No significant nuclear atypia is present. No mitotic activity is apparent. The lesion extends to the inked surface. No skin is present.

See also

References

  1. Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 387. ISBN 978-0443066542.
  2. 2.0 2.1 URL: http://emedicine.medscape.com/article/1058965-overview. Accessed on: 10 September 2011.
  3. Mitchell, Richard; Kumar, Vinay; Fausto, Nelson; Abbas, Abul K.; Aster, Jon (2011). Pocket Companion to Robbins & Cotran Pathologic Basis of Disease (8th ed.). Elsevier Saunders. pp. 597. ISBN 978-1416054542.
  4. URL: http://emedicine.medscape.com/article/1058965-diagnosis. Accessed on: 10 September 2011.
  5. http://www.bccancer.bc.ca/HPI/CE/cytotechnology/cytosleuthquiz/nongyne/ngcase02d.htm
  6. Ioannidis, O.; Stavrakis, T.; Cheva, A.; Papadimitriou, N.; Kotronis, A.; Kakoutis, E.; Makrantonakis, N. (2010). "Pilomatricoma of the arm with extensive ossification.". Adv Med Sci 55 (2): 340-2. doi:10.2478/v10039-010-0010-y. PMID 20439187.
  7. Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 389. ISBN 978-0443066542.