warty dyskeratoma

Definition : Warty dyskeratomas (follicular dyskeratomas) are rare, usually solitary, papules or nodules with an umbilicated or pore-like center.

They have a predilection for the head and neck of middle-aged and elderly individuals.

A subungual and an oral lesion have also been reported.

Warty dyskeratomas average 5 mm in diameter, although an unusually large example, 3 cm in diameter, has been described.

They occasionally bleed or intermittently discharge cheesy material.

There is no evidence of associated Darier’s or Grover’s disease.

PCR analysis for HPV-DNA is negative.

The lesions in comedonal Darier’s disease have the histological features of warty dyskeratoma.

Histopathology

There is a circumscribed, cup-shaped, invaginating lesion extending into the underlying dermis.

The central depression is filled with a plug of keratinous material containing some grains. These keratin plugs have sometimes been dislodged, particularly in oral lesions.

The epidermal component shows suprabasilar clefting with numerous acantholytic and dyskeratotic cells within the lacuna. Protruding into the lacuna are villi, which are dermal papillae covered by a layer of basal cells.

The papillae contain dilated vessels, occasional melanophages, and a few inflammatory cells; inflammatory cells are also present in the underlying dermis. Pilosebaceous follicles may open into the lesion.

A cup-shaped invagination is filled with a keratinous plug which in turn overlies an area of suprabasal clefting.

In a study of 46 warty dyskeratomas accessioned in Graz, Austria, three patterns were discerned on scanning magnification.

The majority were cup-shaped, with a small number of cystic and nodular cases. Mixed patterns were also seen.

The focal contiguity of many of the lesions to pilosebaceous units, and the presence of differentiation towards the follicular infundibulum led the authors to propose the alternative term of ‘follicular dyskeratoma’ for these lesions.

Corps ronds and grains are better developed in the skin lesions than in those in the mouth.

The plaque-like lesion reported as ‘acantholytic dyskeratotic acanthoma’ had features of both warty dyskeratoma and acantholytic acanthoma.

References

 Kaddu S, Dong H, Mayer G, Kerl H, Cerroni L. Warty dyskeratoma—"follicular dyskeratoma": analysis of clinicopathologic features of a distinctive follicular adnexal neoplasm. J Am Acad Dermatol. 2002 Sep;47(3):423-8. PMID: 12196754