RESUMO
BACKGROUND: Congenital aplasia of major salivary glands is a very rare entity, especially if it concerns an ipsilateral aplasia in a nonsyndromic patient. KEY POINTS FROM THE CASE: The aim of this report is to present a case of an aplasia of the left submandibular gland, which was incidentally diagnosed during presurgical imaging for an ipsilateral sublingual ranula. Histopathological evidence of the lack of sublingual gland tissue in the excised specimen of the ranula is discussed. MAIN LESSONS TO BE LEARNED FROM THIS CASE REPORT: Unilateral submandibular aplasia has unknown etiology. Clinicians should be aware of this condition mainly to be able to differentially diagnose a hypertrophy/dysplasia of the contralateral or other major salivary glands, or when xerostomia is the main patient's symptom.