Rare condition of unilateral submandibular gland aplasia and its diagnostic significance in oral cavity carcinoma

Background The unilateral submandibular gland aplasia (agenesis) is a rare, asymptomatic condition usually discovered incidentally on imaging. This is associated commonly with either compensatory hypertrophy of contralateral submandibular gland or sublingual glands. Case presentation We report the case of a 34-year-old male with incidentally detected unilateral submandibular gland aplasia associated with hypertrophy of ipsilateral sublingual gland, demonstrated by imaging modalities, where we have highlighted the diagnostic significance of such rare findings in oncology, particularly in oral cavity carcinoma cases with metastatic submandibular lymph nodes (level IB) mimicking as submandibular gland. Hence, lymphadenopathy can be missed preoperatively which is an important part of staging and treatment planning. Conclusions Aim of the present report is to create awareness about such rare entity in both clinicians/radiologists and highlight the imaging features for correct identification and to avoid any diagnostic dilemmas.