Dermal cylindroma

Dermal cylindroma is a benign skin lesion classically seen on the scalp.

It should not be confused with cylindroma (adenoid cystic carcinoma).

General

• Benign skin lesion.
  • Occasionally malignant.
• May be related to eccrine spiradenoma.

May be familial:

• Familial cylindromatosis (autosomal dominant).
• Brook–Spiegler syndrome.

Gross

• Classically scalp - usually head and neck or face.

Microscopic

Features:

• Nests of cells that fit together like a jigsaw puzzle - the borders of the nests are opposed and undulate.
  1. Basaloid cells with scant cytoplasm and dark nuclei palisade around the edge of the nests.
  2. Larger cells with moderate eosinophilic cytoplasm and lighter staining nuclei are at the centre of the nests.
• Cells nests surrounded by a band of hyaline (i.e. glassy, eosinophilic, acellular) material ~ 2X thickness of a basilar cell - key feature.
  • This is basement membrane.

DDx:

• Eccrine spiradenoma.
• Basal cell carcinoma - has myxoid stroma.

Images

• 

  Dermal cylindroma. (WC/Nephron)

• 

  Dermal cylindroma - high mag. (WC/Nephron)

www:

• Dermal cylindroma (bmj.com).

Stains

• PAS +ve (basement membrane).

See also

• Dermatologic neoplasms.