Table 2. Proposed diagnostic criteria for BHD.

Definite pulmonary BHD	Characteristic or compatible lung HRCT, and skin biopsy positive for fibrofolliculoma or trichodiscoma Characteristic or compatible lung HRCT, and confirmed family history of BHD in first or second degree family member Characteristic or compatible HRCT and tissue confirmation of renal chromophobe adenoma or oncocytoma Characteristic or compatible HRCT and tissue confirmation of genetic testing positive for BHD
Probable pulmonary BHD	Characteristic HRCT, exclusion of TSC and LAMa, and personal or family history of pneumothorax Compatible HRCT, exclusion of TSC and LAM, and any of the following: Family or personal history of renal tumors Skin angiofibroma Renal angiomyolipomab
Possible pulmonary BHD	Compatible or characteristic HRCT

Characteristic lung HRCT findings: Multiple thin-walled round, elliptical or lentiform well-defined air-filled cysts, without internal structure, in a basilar, medial and subpleural predominant distribution, with preserved or increased lung volume, and no other significant pulmonary involvement (specifically no interstitial lung disease)

Compatible HRCT findings: Thin walled cysts without the more typical elliptical shape or subpleural distribution

^aFailure to meet modified Gomez criteria for TSC. Other features that may exclude TSC and LAM include absence of positive serum VEGF-D, surgical lung biopsy negative for LAM, negative genetic testing for TSC, CT or MRI of the head negative for tubers, subependymal nodules or subependymal giant cell astrocytomas

^bRadiographic diagnosis based on fat content by MRI or CT acceptable