Trichofolliculoma with incidental acantholytic dyskeratosis.

Bogle, Cohen, and Tschen have presented a new clinical association for the dermatopathologic changes of acantholytic dyskeratosis. This uncommon histologic marker is characteristic of Darier disease, but can also be seen in a number of other entities. (1)

Trichofolliculomas are small, solitary tumors usually occurring on the face, but occasionally are seen on the scalp or neck. In some cases a small central pore is visible. If such a pore is visible, a fine tuft of white hair may be seen extending from the pore. This finding is characteristic of a trichofolliculoma. Otherwise, these solitary tumors may mimic basal cell carcinoma, nevi, and other dermal tumors.

The typical pathologic feature of a trichofolliculoma contains a large cystic space that is lined by squamous epithelium and contains keratin. Radiating from the wall of these primary hair follicles, one may see small secondary hair follicles. Small groups of sebaceous gland cells may be embedded in the walls of the secondary hair follicles.

Dyskeratosis is a faulty and premature keratinization of individual keratinocytes. Acantholytic dyskeratosis occurs as corps ronds, which consists of a central, homogenous, basophilic pyknotic nucleus surrounded by a clear halo. Acantholytic dyskeratosis is an important marker seen only in a few diseases.

Why would this newly reported histopathologic association be reportable? Good correlation between the clinical observation and the pathologic findings is critical to accurate diagnosis. Today, many clinicians of all specialties obtain skin biopsy specimens. Frequently these specimens are processed by commercial labs and are interpreted by general pathologists. Noting an association between trichofolliculoma and acantholytic dyskeratosis expands the differential diagnosis of this important marker. Ultimately, this will improve clinical diagnosis by the physician.

Anybody can become angry--that is easy; but to be angry with the right
person, and to the right degree, and for the right purpose, and in the
right way--that is not within everybody's power and is not easy.
--Aristotle

Please see "Trichofolliculoma with Incidental Focal Acantholytic Dyskeratosis" on page 773 of this issue.

References

1. Lever WF, Shaumburg-Lever G. Histopathology of the Skin, JB Lippinott Co, ed 6, p 763.

Larry D. Hudson, MD

From Dermatology and Dermatologic Surgery, P.C. and Laser Center, Johnson City, TN.

Reprint requests to Larry D. Hudson, MD, 1021 W. Oakland Ave., Suite 102, Johnson City, TN 37602.