Neurofollicular hamartoma presents as a smooth flesh-coloured papule on the face.
Histology of neurofollicular hamartoma
In neurofollicular hamartoma, the histopathology shows a nodulardermalspindle cellproliferation surrounded by prominent sebaceousglands. The spindle cells are plump or wavy. The sebaceous proliferation surrounds the mesenchymal component (figures 1–3).
Figure 1
Figure 2
Figure 3
Special studies for neurofollicular hamartoma
The spindle cells are positive for S100, CD34 and Factor XIII.
Differential diagnosis for elastofibroma
Other diagnoses to be considered include:
Trichodiscoma — some authorities regard neurofollicular hamartoma to be a form of trichodiscoma.
S100 is usually negative in trichodiscoma
Neurofibroma and neurotised naevus do not usually have malformed follicular and sebaceous structures.
References
Requena L, Yus ES, Simón P, del Rio E. Induction of cutaneous hyperplasias by altered stroma. Am J Dermatopathol. 1996 Jun;18(3):248–68. PubMed PMID: 8806959.