*4.5.1 Adenocarcinoma not otherwise specified (NOS)*

It is an aggressive invasive tumour showing features that are not specific for any particular tumour type. It is a usually a diagnosis of exclusion. It constitutes 10–15% of all SG tumours and about 40% cases are reported in minor salivary glands with palate being the most common site [48].

**Key cytological features –** It shows glandular or ductal differentiation but patterns and cellular features are non-specific. The cells may be seen in nests, tubules, clusters or cords. The cellular features are variable and range from subtle low-grade tumours to a high-grade carcinoma.

Other SG carcinomas such as salivary duct carcinomas, intraductal carcinoma, lymphoepithelial carcinoma, primary squamous cell carcinoma and carcinosarcomas are rare and are reported to occur in major salivary gland and not in intraoral minor SGs.

### **4.6 Tumour-like lesions of intraoral salivary glands**
