*4.6.1 Mucocele*

Amongst non-neoplastic lesions, mucocele or mucous retention cyst occur in intraoral SGs and can mimic a low-grade cystic tumour. Mucocele is a pseudocyst which lack epithelial lining and contain extravasated mucin. These usually develops in minor SGs particularly on the lips and other sites such as tongue [49]. FNAC smears from mucocele are hypocellular with histiocytes and muciphages in an abundant mucoid background**.** Few giant cells can also be seen. Cystic consistency and mucoid background with muciphages may raise a possibility of low-grade MEC but other features of MEC such as intermediate and epidermoid cells are absent.

#### *4.6.2 Sialadenosis (SA)*

**Sialadenosis (SA)** is non-inflammatory and non-neoplastic enlargement of SGs predominantly occurring in parotid. However, it is also documented to occur in minor SGs in few reports in literature [50]. Aspirates from SA show plenty of acinar cells with hypertrophic changes. Sometimes, the cells may resemble cells of AciCC but in SA the architecture of normal SG tissue is maintained with regularly arranged acini instead of overlapping three-dimensional clusters, groups and sheets of acini in AciCC.

#### *4.6.3 Sialadenitis*

Inflammation of SGs may result from various causes but predominantly it occurs due to stenosis or obstruction of SG ducts because of sialolithiasis, trauma or secondary involvement by tumours [51, 52]. It may present with swelling and sometimes mimic a neoplasm.

*Cytopathology of Intraoral Salivary Gland Tumours and Tumour-Like Lesions… DOI: http://dx.doi.org/10.5772/intechopen.98872*

### *4.6.4 Acute sialadenitis (AS)*

**Acute sialadenitis (AS)** is usually a bacterial inflammation of the SGs and usually affects the parotid. However, it may also affect minor SGs [52]. Aspirates from AS usually shows abundant neutrophils, macrophages, few duct cells with reactive changes in a degenerating background. Sometimes, AS may occur as a part of underlying tumour. Non-regressive swelling on antibiotic treatment with abundant obscuring inflammation showing even focal evidence tumour such as chondromyxoid material or mucin laden or keratinized cells, should raise suspicion of a underlying hidden tumour and need to be followed-up by reaspiration or biopsy.
