Introduction: The BirtHoggDube syndrome (BHDS) is a rare autosomal dominant genodermatosis characterised by presence of at least one of the following: benign skin fibrofolliculomas, lung cysts with recurrent pneumothoraces or renal tumours. The phenotypic constellation is due to heterozygous germline mutations of the tumour suppressor gene FLCN, located on 17p11.2, encoding a 579 aminoacid protein termed folliculin. Case reports have described endocrine tumours of the thyroid, parathyroid, in addition to neuroendocrine tumours, colon cancer, melanomas, meningiomas and squamous cell carcinoma. To our knowledge, only one case of an adrenal tumour has been previously reported in association with BHDS.
Case report: A 36-year-old woman, presenting to the urologists with urinary frequency, was found to have a 110×95×56 mm left adrenal tumour on CT imaging, following a preliminary ultrasound. She underwent an uncomplicated open adrenalectomy for a presumed non-functioning adrenal carcinoma. Histology revealed a non-functioning adrenocortical tumour with no malignant features. In the view of the family history of BHDS, FLCN mutational analysis was requested. The presence of a frameshift mutation in exon 11 (p.His429ProfsX27) confirmed the diagnosis of BHDS. Post-operative PET scanning did not show any evidence of metastatic disease. A decision was made not to commence adjuvant mitatone chemotherapy and to arrange follow-up imaging. Genetic screening for her two children was discussed.
Conclusions: Adrenal tumours are likely to be a rare feature of BHDS, however their presence should be sought in people affected with this condition. The likely mechanism of tumourigenesis is the two-hit process. The relative sparing of the adrenals compared to other endocrine organs merits further investigation.