Case 1

In a recent case report, Cole et al. (2020) describe an incidental finding of bilateral kidney tumors and subsequent diagnosis of BHD in a 70-year-old man. A routine blood test suggested the presence of kidney disease, leading to an ultrasound and subsequent CT imaging. The images revealed bilateral kidney cancer and pulmonary cysts at the base of his lungs. Considering these results, alongside a medical history of multiple pneumothoraces and fibrofolliculomas, it was suspected that the patient had BHD. Genetic testing showed a mutation in the FLCN gene, supporting this diagnosis.

The patient underwent a robotic assisted surgical procedure, called a partial nephrectomy, to remove the larger kidney tumors. A tissue sample from the tumor was analyzed and the patient was diagnosed with a ‘hybrid oncocytic tumor associated with BHD’.

Cole A, Garber J, Baniak N, Hirsch M et al ‘Case of the Month’ from Brigham and Women’s Hospital, Boston: a 70-year-old man with lung cysts and bilateral renal masses. BJU International, 2020; 126: 428-432  

Case 2

A recent case report by Adhikari et al. (2021), describes a young women’s 5-year journey to be diagnosed with BHD. At the age of 30 she developed chest pain and breathlessness after air travel and was diagnosed with a pneumothorax, which was successfully treated. However, 3 months later she found herself readmitted to hospital due to another pneumothorax. On the third admission, as well as a newly collapsed lung, she was noted to have fibrofolliculomas and a family history of pneumothoraces. Further tests showed a variation of her Folliculin gene, and she was diagnosed with BHD syndrome at the age of 35.

Adhikari N, Karki A, A case report of recurrent pneumothoraces as a presentation of Birt Hogg Dube syndrome, Respiratory Medicine Case Reports, 2021; 32:101340.

Case 3

A case report by Tzilas et al (2020) describes two men with nonspecific respiratory symptoms, who were diagnosed with BHD.  A 65-year-old man presented to hospital with breathlessness and a history of recurrent respiratory infections. The chest x-ray was normal.  However, he was investigated further with a CT scan which showed lung cysts, predominately at the base of the lungs. He was noted to have fibrofolliculomas and diagnosed with BHD. The second case describes a 55-year-old man with a long-standing cough, whose CT scan showed multiple lungs cysts. Similarly, to the first patient he was noted to have fibrofolliculomas and diagnosed with BHD.  This case report discusses how lung symptoms in patients with BHD are rare, with the exception of pneumothoraces, and that lower lung cysts in the absence of any other radiological feature is suggestive of BHD.

Tzilas V, Sgouros D, Almpanis Z, Bouros D, Tzouvelekis A. Cystic lung disease in Birt-Hogg-Dubé syndrome. A case series, Respiratory Medicine Case Reports, 2020 ; 30:101081

These case studies show how BHD can present in a variety of different way making it difficult to diagnose as it is often not recognised. Through recording cases such as these we can develop a greater understanding and raise awareness of this rare and important condition.