🔍 Search
Benign adnexalICD-10 D23.4

Syringocystadenoma papilliferum

SCAP; syringocystadenoma papilliferum

Syringocystadenoma papilliferum is a benign adnexal tumour of apocrine and/or eccrine differentiation, classically arising in a pre-existing naevus sebaceus of Jadassohn on the scalp or face in childhood or adolescence. It presents as a pink, weeping, papillomatous papule or plaque that may discharge serous fluid. Histology shows characteristic papillary projections lined by two layers of epithelium with a dense plasma-cell infiltrate. BRAF-mutation overlap is recognised. Complete excision is curative; rare malignant transformation (syringocystadenocarcinoma papilliferum) has been reported.

CurrentLast reviewed 15 May 2026

Clinical features

  • Solitary pink or red papule, plaque or nodule with verrucous, papillomatous surface, sometimes with serous discharge or crusting.
  • Distribution — scalp (commonest), face, neck; chest, axilla.
  • Often arises within a pre-existing naevus sebaceus on the scalp at puberty.
  • Occasionally congenital or appearing in early adulthood.
  • May ulcerate or bleed with trauma.

Histology

  • Cystic invaginations from the surface epidermis into the dermis, lined by papillary projections of two-layered epithelium — luminal columnar cells with decapitation secretion and outer cuboidal cells.
  • Dense plasma-cell-rich infiltrate within the papillary stroma is highly characteristic.
  • BRAF V600E and HRAS mutations have been described.
  • Differential — hidradenoma papilliferum, tubular apocrine adenoma, syringocystadenocarcinoma papilliferum (malignant counterpart with atypia/infiltration).

Context — naevus sebaceus association

  • Approximately 5–15% of naevus sebaceus develop secondary neoplasms; syringocystadenoma papilliferum and trichoblastoma are the commonest benign secondary tumours.
  • BCC and other malignancies are rare but recognised.
  • This is the rationale for prophylactic excision of naevus sebaceus around puberty, although modern practice often defers excision to symptomatic change.

Management

  • Complete surgical excision with histology.
  • If arising within naevus sebaceus — excise the entire naevus with a small margin.
  • Reassurance after complete excision for confirmed benign disease.
  • Suspicious features (rapid growth, ulceration, infiltration) — exclude syringocystadenocarcinoma papilliferum; wide local excision with MDT discussion.

References

  1. Helwig EB, Hackney VC. Syringocystadenoma papilliferum. Arch Dermatol; 1955.
  2. Idriss MH, Elston DM. Secondary neoplasms within naevus sebaceus — a review. J Am Acad Dermatol; 2014.
  3. WHO Classification of Tumours Editorial Board. Skin Tumours, WHO Classification of Tumours, 5th ed., vol. 12. Lyon: IARC; 2025.

Spot a correction?

If any clinical statement, citation or link on this page needs updating, please email admin@skinoncology.net with the page name, the proposed correction and the supporting source.