RESUMEN
Leukemic infiltration of the gingival tissue associated or not with gingival enlargement may be the first manifestation of acute leukemia, despite being rarely reported in the literature. A 10-year-old female patient presented with a 1-month history of an asymptomatic, firm, and pinkish-red generalized gingival overgrowth. There was no bone resorption. Incisional biopsy of the gingival tissue was performed, with histopathological examination revealing a diffuse and hypercellular infiltration of monocytoid cells. The patient was referred to a hematologist and underwent a bone marrow biopsy, which led to a conclusive diagnosis of acute myeloid leukemia. The patient was treated with chemotherapy and we observed regression of gingival enlargement after 4 weeks from the initial therapy.