"Adenoid cystic carcinoma" is a malignant tumour of secretory glands. It is also known by other names like "adeno cystic carcinoma", "cylindroma" etc. Although this tumour most often occurs in the salivary glands, it can also be found in many anatomical sites, including the breast, lacrimal gland, lung, brain, bartholin gland, trachea, and the paranasal sinuses. But why the term "adenoid" is used in relation to it?