Lip biopsy for the diagnosis of Sjögren's syndrome: beware of the punch

A pilot study was performed to examine the presence of nerve fibres in minor salivary gland tissue samples obtained by two procedures: punch and linear incisional techniques. The study was undertaken on a convenience sample of five cryopreserved corpses (mean age 74 ± 3.5 years; three males and two females). Biopsies were performed on the buccal side of the lower lip, between the mid-line and the corner of the mouth. Each corpse had one side of the lower lip biopsied by punch and the contralateral side using a linear incision. All punch samples (100%) displayed severed nerve fibres, whereas no nerve fibres (0%) could be identified in the samples obtained by means of the linear incision technique. While the linear incision approach permitted retrieval of at least five glands, punch biopsies did not provide enough material for the diagnosis of Sjögren's syndrome. Within the limitations of the study, our results strongly discourage the punch technique for minor salivary gland lip biopsy and provide information on the superiority of the linear incisional biopsy in terms of neural damage. These results may also promote the undertaking of clinical trials on patients in whom Sjögren's syndrome is suspected, comparing the morbidity associated with the linear incisional technique vs. minimally invasive biopsies.