More or less complete trichogenic or proximal follicular units that radiate from a central lumen or  lumina lined by infundibular epithelium characterize trichofolliculomas and variants. These features can be present, uncommonly and to a lesser degree, in pilar sheath acanthomas. Rather cellular fibroblastic stroma of the type seen in traditional trichoepitheliomas is usually present in trichofolliculomas.

In contrast, those tumors that have been designated as fibroepithelial follicular hamartomas, such as perifollicular fibromas and fibrofolliculomas, lack the architecture of trichofolliculomas though trichogenic components may be present to a minimal degree . The epithelial components of the fibroepithelial follicular hamartomas more closely resemble infundibular, isthmic, or mantle counterparts. Uncommitted or 'primordial' differentiation is allowable  but is not seen to the extent found in  the  fibroepithelioma of Pinkus.  The stroma is prototypically sparsely cellular and eosinophilic though a myxoid component may be present. It is sometimes difficult to distinguish primordial follicular epithelium from hair bulb epithelium, but follicular differentiation is inferred in the absence of intimate association with moderately cellular, basophilic stroma of hair bulb papilla type.

The current case illustrates the point that many combinations and permutations of follicular components may be encountered in benign follicular tumors. It would be a chore to assign each of these a different name. 

From the helix of the right ear of a 61 year old male:
 

	Scan power view showing follicular structures radiating from a central lumen or, perhaps, lumina. The follicular epithelial components are associated with a large amount of eosinophilic follicular sheath type of connective tissue. There is a small wedge of normal dermis near the top of this picture.
	A medium power view of the wedge of normal dermis, outlined in black. Compare this to the special stroma that is an integral part of the tumor.
	A medium power view of the lumen showing outlines of hair shaft-type material.
	A medium power view of a trichogenic component having a well-developed hair bulb. The papilla is more basophilic and cellular than the surrounding connective tissue.
	A medium power view of less mature or less organized slender strands of follicular epithelium associated with a large amount of eosinophilic follicular sheath stroma.
	A high power view of the above. Although the basaloid epithelium forms a concave base, the connective tissue in the base is not of hair bulb type. All of the connective tissue is of eosinophilic follicular sheath type.

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