Familial pulmonary cysts: A clue to diagnose Birt-Hogg-Dubé syndrome: A case report and literature review

Abstract

Birt-Hogg-Dubé syndrome (BHD) is an inherited autosomal dominant condition caused by germline mutations in the FLCN gene, mapped to chromosome 17p11.2. Typical manifestations include pulmonary cysts, spontaneous pneumothorax, fibrofolliculomas, and kidney neoplasms. This report details the case of a 56-year-old female non-smoker diagnosed with multiple pulmonary cysts, presenting with a history of recurrent spontaneous pneumothorax. A computed tomography (CT) scan of her daughter revealed similar pulmonary cysts, raising suspicion of BHD. Further abdominal enhanced CT revealed a left renal tumour and cutaneous fibrofolliculomas on her daughter's neck. Consequently, whole-exome sequencing confirmed an FLCN germline mutation in the patient and three relatives, establishing a diagnosis of BHD. This case highlights the importance of familial pulmonary cysts as a clue for diagnosing BHD, providing crucial insights into comparable clinical presentations.

Keywords: Birt–Hogg–Dubé syndrome; FLCN gene; familial pulmonary cysts.

FIGURE 1

(A, B) Chest computed tomography (CT) scans of the patient and her daughter reveal multiple thin‐walled parenchymal cysts. (C) Enhanced abdominal CT of the patient indicates a left renal tumour, referred by a red arrow. (D) Shows cutaneous fibrofolliculomas observed in the daughter's neck. (E) Pedigree chart of the patient's family in three generations.