Fibrofolliculomas are exactly the same as trichodiscoma, except they have the additional feature of a central follicular structure with numerous thin basaloid epithelial strands extending into the fibrous component (66) (Figure 15, B).
Trichodiscomas are benign hamartomas of the mesenchymally derived perifollicular fibrous root sheath.
Hereditary multiple fibrofolliculomas with trichodiscomas and acrochordons.
The benign tumors are: Trichofolliculoma, Pilar sheath acanthoma, Fibrofolliculoma, Trichodiscoma
, Trichoepithelioma, Trichoblastoma, Trichoadenoma, Pilomartricoma, Trichilemmoma, Trichilemmal horn and Proliferating trichilemmal cyst.
These tumors may occur sporadically or in association with Birt-Hogg-Dube syndrome, which is associated with cutaneous (fibrofolliculoma, trichodiscoma
, or acrochordon) and pulmonary (cysts and pneumothorax) lesions.
In 1977, Birt, Hogg, and Dube reported on a group of patients from single kindred who had multiple fibrofolliculomas with trichodiscomas and acrochordons .
Dube, "Hereditary multiple fibrofolliculomas with trichodiscomas and acrochordons," JAMA Dermatology, vol.
(40) Patients may also develop associated skin manifestations, including cutaneous fibrofolliculomas, trichodiscomas
, and perifollicular fibromas, and are potentially at risk of melanoma.
Acrochordons are one of the components of Birt-Hogg-Dune syndrome, the other components being fibrofolliculomas and trichodiscomas
. As acrochordons are asymptomatic, treatment is sought for cosmetic concerns only.
This condition is associated with kidney cancer and is marked by benign fibrofolliculomas and trichodiscomas
that most often occur on the head and neck.
(85) Genetic predisposition to the development of ChRCC, particularly so-called hybrid oncocytic/chromophobe tumors that show overlapping features of oncocytoma and ChRCC, is seen in patients with Birt-Hogg-Dube syndrome, which is associated with germline folliculin (FLCN) mutations; these patients often develop multiple, bilateral, oncocytic renal neoplasms, including ChRCC, hybrid oncocytic/chromophobe tumors, and oncocytoma, and may also have characteristic skin (ie, fibrofolliculomas, trichodiscomas
) and lung (ie, subpleural cystic blebs) findings.
Birt-Hogg-Dube (BHD) syndrome is a rare condition inherited in an autosomal-dominant fashion and characterized by unique skin lesions (multiple fibrofolliculomas, trichodiscomas
, and acrochordons) and associated internal organ lesions, such as intestinal polyps, renal and lung cysts, and medullary thyroid carcinoma in the original description.