Table 1.

Observations seen in various case series on BHD syndrome [1–3] as well as in our patient

Tumor site	Observations in BHD syndrome	Observations in our patient
Skin	Fibrofolliculomas, trichodiscomas, and acrochordons on the face, neck, and upper torso	Our patient has had multiple dermatological visits, with removal of acrochordons several times.
Skin	Melanoma	Yes
Skin	Lipoma	Yes
Skin	Squamous cell carcinoma	Yes; along with multiple biopsies of suspicious lesions which showed actinic keratosis.
Lung	Pulmonary air-filled cysts/bullous emphysematous changes	Yes; bullous emphysematous changes are noted in the left upper lobe in our patient, leading to repeated spontaneous pneumothoraces (fig. 1).
Lung	Spontaneous pneumothorax	Yes; our patient has had repeated admissions for pneumothoraces with persistent air leaks most likely due to rupture of various blebs.
Kidney	Renal tumors (clear cell and papillary)	Yes; renal cell carcinoma (clear-cell type), including renal bilateral renal cysts.
Colon	In the past, an association between BHD syndrome and colorectal polyps and cancer was also suggested. However, recent studies indicate that colorectal tumors are not associated with the syndrome or, alternatively, occur only in a small subset of families.	Yes; our patient had a colorectal adenoma excised on a colonoscopy. Biopsy showed tubulovillous adenoma.
Other rare tumors	Other tumors were reported in 11 clinically affected BHD patients and/or carriers of mutations in the folliculin gene: benign breast disease, oral fibroma, lipomas, inverted papilloma of the nose, fibrosarcoma of the leg, skin basal cell carcinoma, human immunodeficiency virus-related B-cell non-Hodgkin lymphoma and breast cancer.