Lichenoid granulomatous stomatitis: a series of 12 cases and a literature review.

BACKGROUND: Lichenoid granulomatous stomatitis (LGS), characterized by a combined histopathological presentation of lichenoid reactions and granulomatous inflammation, is a rare oral disease. Although it has been reported previously, it has never been assessed specifically. METHODS: We retrieved cases presenting with both lichenoid reactions and granulomatous inflammation between January 1, 2013, and May 1, 2024, at the Peking University Hospital of Stomatology. LGS diagnosis was based on the histopathological presence of both lichenoid reactions and granulomatous inflammation. We retrospectively assessed the clinicopathology of all the included patients. We also conducted a literature review of relevant literature highlighting the demographic and clinicopathological characteristics of LGS. RESULTS: In total, 12 patients with tissue from 13 biopsy sites were included. Most patients (83.33%) were females, and the mean age was 46.58 ± 14.37 years (range = 22–68 years). All patients were of Chinese descent, and the most common LGS site was the dorsum of the tongue (n = 7), followed by labial mucosa (n = 6), buccal mucosa and vestibule (n = 5), gingiva (n = 2), and most multifocal involvement (n = 7). The clinical manifestations of LGS ranged from swelling to reticulated plaques and erythematous or erythroleukoplakic appearance. Histopathologically, the lesions were characterized by lichenoid reactions concomitant with granulomatous inflammation. Based on Magro and Crawson’s classification system for lichenoid granulomatous dermatitis, six, six, and one biopsy samples were classified into type I, II, and IV LGS, respectively. In particular, the biopsy sites for all type II LGS samples were the dorsum of the tongue, whereas those for most type I LGS samples were the labial and buccal mucosa. Most patients were treated with Chinese patent medicine or tacrolimus ointment, which led to symptom relief but not complete resolution. CONCLUSION: LGS is a distinct entity, often multifocal (notably the tongue), with mixed lichenoid-granulomatous features and site-histotype correlations. Treatments alleviate symptoms but not disease, highlighting the need for further study.