Pathological and Immunohistochemical Characteristics of Granuloma and Lymphatics in Cheilitis Granulomatosa.

Cheilitis granulomatosa (CG) is an idiopathic, rare, and chronic granulomatous disorder involving the lips. We characterized the pathological and immunohistopathological findings of these granulomas and their relationship with the lymphatic vessels. Pathologically confirmed cases of primary CG from 2001 to 2016 were collected. Cases of inflammatory cheilitis without the presence of granuloma were included in the control group. Demographic data, clinical presentation, response to therapy, and pathological differences were compared. Periodic acid-Schiff and acid-fast stains excluded patients having infections. CD68, CD163, and D2-40 stains demonstrated features of granuloma, macrophage polarization, and the relationship between granuloma and lymphatic vessels. Thirteen patients diagnosed with CG were enrolled. Thirteen people were enrolled in the control group. The granulomas were either mononuclear or sarcoidal. They were predominantly positive for CD68 but negative for CD163. Perilymphatic granulomas were found in all patients. Intralymphatic histiocytosis and lymphatic dilatation were more commonly observed in patients diagnosed with CG than those in controls (54% vs. 15%, P = 0.03 and 92% vs. 23%, P < 0.01). TH1 immune response due to CD68+ M1 macrophages results in CG. Perilymphatic aggregation of macrophages and intralymphatic histiocytosis were important pathological clues for diagnosis.