Paraglottic Mass and Birt–Hogg–Dubé (BHD) Syndrome
BHD is a rare autosomal dominant genetic disorder caused by pathogenic variants in the FLCN (folliculin) tumor-suppressor gene on chromosome 17p11.2. It is characterized by a triad of benign cutaneous fibrofolliculomas, especially on the face; multiple pulmonary cysts with recurrent spontaneous pneumothorax; and an increased risk of bilateral or multifocal renal tumors, most commonly renal cell carcinoma, oncocytoma, or hybrid oncocytic tumors.
Cutaneous lesions are benign but occasionally require cosmetic surgery; pulmonary disease confers lifelong pneumothorax risk that can eventually lead to talc or other sclerosing agent pleurodesis (to adhere visceral and parietal pleura to prevent further pneumothoraxes). Renal malignancy risk is the major determinant of prognosis. The latter risk may be reduced by protection of kidney function and regular renal surveillance such as with serial MRI scans.
Laryngeal involvement is not typical, though a single case report has described an adult-type laryngeal rhabdomyoma, presenting as a supraglottic mass involving the piriform sinus/paraglottic region, in a patient with BHD. There are other reports in persons who do not have BHD of paraglottic rhabdomyomas or lipomas, both of which are benign and relatively avascular.
Paraglottic Mass and BHD Syndrome
This elderly patient has suffered at least 6 episodes of pneumothorax due to her known BHD syndrome. She has several family members (mother, aunts) who also have this condition. After her last two pneumothoraxes, cysts making her at risk of further pneumothoraxes were removed, and powder introduced into the pleural space to adhere visceral and parietal pleura.
Her reason for laryngology consultation is a very poor voice across several years, and gradually getting worse. On evaluation, her voice is functional but strained, effortful, and very hoarse. Laryngeal examination shows a bulging but mostly mobile left vocal cord, due to a submucosal mass. CT scanning shows a well-defined paraglottic mass without cartilage destruction.
If pulmonary function and risk of further pneumothorax check out, the plan is removal under general anesthesia. An “upper Dutch door” is planned, dividing 1/3 of the way down from the thyroid notch and then proceeding with a cartilage cut directed straight posteriorly, parallelling the ventricle. Anterior commissure attachment is preserved. The posterior edge of the pre-epiglottic fat would be identified and retracted forward to provide access to the paraglottic mass, which should be able to be dissected up and out of the paraglottic space. It is quite possible that a tracheotomy could be avoided if there is no entry into the lumen (no rent in mucosa), but of course the patient is consented for possible (temporary) tracheotomy. The patient is deciding…
Submucosal mass (1 of 7)
Bulging (2 of 7)
Phonation (3 of 7)
Axial CT (4 of 7)
Mass invading ventricle (5 of 7)
Superior view (6 of 7)
Near thyroid cartilage (7 of 7)
References for Further Reading
Balakumar R, Farr MRB, Fernando M, Jebreel A, Ray J, Sionis S. Adult-type rhabdomyoma of the larynx in Birt–Hogg–Dubé syndrome: Evidence for a real association. Head Neck Pathol. 2019;13(3):507–511. PMID: 29744825. doi:10.1007/s12105-018-0922-6.
Share this article