Published Web Locationhttps://doi.org/10.5070/D36np4b9j4
From the Ronald O. Perelman Department of Dermatology, New York University
Lisa Moed Gruson MD
Dermatology Online Journal 10 (3): 15
A 27-year-old woman presented with multiple growths on her face and upper body, which she has had for several years. She also reported that her mother and maternal grandmother have similar lesions and that her mother has been diagnosed with Birt-Hogg-Dube syndrome. Histopathologic features of one papule demonstrated basaloid cells emanating from a dilated follicular infundibula surrounded by a well-circumscribed fibromucinous stroma. Birt-Hogg-Dube syndrome is an autosomal-dominant-inherited condition characterized by fibrofolliculomas, trichodiscomas, and acrochordons. It is associated with renal tumors, spontaneous pneumothoraces, and possibly intestinal polyps. Treatment includes evaluation for associated renal, lung, and intestinal findings as well as cosmetic removal of skin lesions.
History.—A 27-year-old woman presented to the Charles C. Harris Skin and Cancer Pavillion for evaluation of multiple growths on her face and upper body, which she has had for many years. The lesions were removed 3 years prior, however, many have returned. She denied any other medical problems. The patient also stated that her maternal grandmother, mother, and sister have similar skin findings. Her grandmother has had colon cancer as well, and her mother has had a pneumothorax. Her sister, who is 26 years old, has not experienced any associated medical conditions. The patient stated that these lesions are asymptomatic; however, she had them removed in the past for cosmetic reasons. She also was concerned that she may have Birt-Hogg-Dube syndrome as her mother was recently diagnosed with this condition.
Physical examination.—On the face, neck, chest, upper back, and axillae, multiple, pedunculated, flesh-colored papules were present. Some of these papules have the appearance of containing hair follicles.
|Figure 1||Figure 2|
Laboratory data.—Computed-tomography scans of the chest, abdomen, and pelvis and colonoscopy were normal
Histopathology.—Emanating from the dilated follicular infundibula are thin strands of basaloid cells that are surrounded by a well-circumscribed mantle of fibromucinous stroma.
Birt-Hogg-Dube syndrome (BHDS) is an autosomal dominant condition that was first described in 1977.  At that time, the associated clinical findings included the grouping of three benign skin tumors: fibrofolliculomas, trichodiscomas, and acrochordons. These skin lesions are described as flesh-colored papules that are distributed on the face, neck, upper trunk, and sometimes axillae.  However, more recently renal tumors and spontaneous pneumothoraces have become associated with this condition.  The odds ratio for developing renal tumors in patients with BHDS is 6.9.  Some reports also have cited an association between intestinal polyps and Birt-Hogg-Dube syndrome.  However, whether this association is causal or coincidental remains unsubstantiated. [2,3] The BHDS locus has been mapped to chromosome 17p12-q11.2 and found to encode a novel protein named follicullin. [3,4]
Histologically, fibrofolliculomas are circumscribed proliferations of collagen and fibroblasts that surround distorted hair follicles from which basaloid cells protrude into the surrounding fibromucinous stroma. Trichodiscomas histologically appear as sharply defined fibrovascular tumors in the superficial dermis.  There is continuing debate as to whether trichodiscomas and fibrofolliculomas are variations of the same lesion as they share the same epithelial and mesenchymal components. Some authors speculate that these two lesions may represent a spectrum of progressive differentiation.  One publication has now defined any individual as having BHDS if he or she has greater than ten lesions clinically consistent with fibrofolliculomas and a minimum of one lesion confirmed as a fibrofolliculoma by examination of a biopsy specimen. 
The evaluation for patients with Birt-Hogg-Dube syndrome includes a complete history and physical examination, computed-tomography scans of the abdomen and pelvis, and a chest roentgenogram. Some authors also suggest a colonoscopy. These patients should be followed as renal tumors become more frequent with advancing age. [1,2]
Treatment for patients with Birt-Hogg-Dube syndrome includes screening and management of pulmonary, renal, and gastrointestinal findings. In addition, skin findings may be treated for cosmetic concerns. Options for removal of these lesions include electrocautery, dermabrasion, and resurfacing with the carbon dioxide or Er:YAG lasers. 
References1. Vincent A, et al. Birt-Hogg-Dube syndrome: a review of the literature and the differential diagnosis of firm facial papules. J Am Acad Dermatol 2003; 49: 689.
2. Zbar B, et al. Risk of renal and colonic neoplasms and spontaneous pneumothorax in the Birt-Hogg-Dube syndrome. Cancer Epidemiol Biomarkers Prev 2002; 11: 393.
3. Kahnoski K, et al. Alterations of the Birt-Hogg-Dube gene in sporadic colorectal tumors. J Med Genet 2003; 40: 511.
4. Khoo SK, et al. Birt-Hogg-Dube syndrome: mapping of a novel hereditary neoplasia gene to chromosome 17p12-q11.2 Oncogene 2001; 20: 5239.
5. Heenan PJ. Tumors of the fibrous tissue involving the skin. In Elder D, et al, Eds. Lever's Histopathology of the Skin. Philadelphia: Lippincott, Williams and Wilkins; 1997: 870.
6. Jacob CI, Dover JS. Birt-Hogg-Dube syndrome: treatment of cutaneous manifestations with laser skin resurfacing. Arch Dermatol 2001; 137: 98.
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