Primary epithelial-myoepithelial carcinoma of the pituitary gland

Primary salivary gland-like tumors of the sella are rare and often challenging to diagnose. They reportedly derive from serous and mucinous glands that remain trapped in the infundibulum during embryogenesis. We report a 68-year-old man who presented with partial left third cranial nerve palsy, visual loss in the left eye without visual field defects, headache, weight loss and reduced muscle bulk. Neuroimaging studies demonstrated a solid and cystic, avidly enhancing lesion expanding the pituitary fossa and extending to the left cavernous sinus. The patient underwent craniotomy and the tissue removed showed features of epithelial-myoepithelial carcinoma similar to the salivary gland, skin and breast counterpart. No primary tumor was found outside the sella. The lesion behaved aggressively despite radio-chemotherapy and the patient died 22 months from the onset. The tumor showed a novel TP53 in-frame deletion (Gly154del) while no variants were found in H-RAS hotspot regions (codons 12, 13 and 61). Our report expands the spectrum of salivary gland-like tumors primarily occurring in the sella and emphasizes the need for specialist review of rare, non-neuroendocrine tumors of the pituitary and sella regions.     

Continuous measurement of intra‐oral pH and temperature: development,validation of an appliance and a pilot study

To describe a novel approach for continuous measurement of intra‐oral pH and temperature in individuals carrying out normal daily activities over 24 h. We designed, validated and constructed a custom‐made appliance fitted with a pH probe and a thermocouple. Six subjects wore the appliance over a 24‐h period for two non‐consecutive days, while the intra‐oral pH and temperature were measured continuously and recorded. Intra‐oral pH and temperature were very similar across different recording days, the difference being not statistically significant (P ≥ 0·14). There was a noticeable difference in the pattern of variation of pH between day and night. During the day, the mean pH was 7·3 (±0·4) and dropped markedly only after consumption of acidic food and drinks. The intra‐oral pH decreased slowly during sleep with an average pH of 6·6 (±0·4) being recorded. The difference between day and night was statistically significant (P = 0·002). The mean intra‐oral temperature was 33·9 °C (±0·9) during daytime and 35·9 °C (±0·5) during sleep (P = 0·013) with minor fluctuations occurring over 24 h. The continuous and simultaneous intra‐oral pH and temperature measurement system described in this report is reliable, easy to construct, able to measure variables over a sustained period and may serve as a future diagnostic tool in a number of applications.     

A study on the inhibition of VEGF expression in salivary gland adenoid cystic carcinoma cells via iNOS gene RNAi in vitro

In this study, we aimed to explore the effect of inducible nitric oxide synthase (iNOS) on vascular endothelial growth factor (VEGF) expression in salivary gland adenoid cystic carcinoma (SACC). Using RNAi, we transfected chemically synthesised iNOS siRNA into ACC‐M cells (a highly metastatic adenoid cystic carcinoma cell line) and detected the change in the gene and protein expression levels of iNOS and VEGF by qRT‐PCR and Western blotting. A transwell invasiveness assay was used to examine the changes in invasive ability of ACC‐M cells. Cell growth was determined using a CCK‐8 assay. Apoptosis and cell‐cycle phases were detected by flow cytometry. We found that silencing iNOS down‐regulated the expression of VEGF and then inhibited cell growth and invasiveness of SACC cells, while it increased apoptosis. Therefore, we concluded that iNOS can regulate VEGF expression and iNOS may be a therapeutic target.     

Surgical management of deep lobe parotid tumours with and without involvement of the parapharyngeal space

The diagnosis and treatment of deep lobe parotid tumours is challenging because of the complex surgical accessibility. There is a lack of studies describing the differences between deep lobe tumours that do and do not occupy the parapharyngeal space (PPS). Patients treated for deep lobe tumours occupying the PPS (PPS group) and not occupying the PPS (non-PPS group) were analysed retrospectively. A total of 227 patients were treated surgically for deep lobe parotid tumours between 1990 and 2019. Sixty patients (26.4%) presented with tumours that involved the PPS (PPS group), while 167 (73.6%) presented with tumours that did not occupy the PPS (non-PPS group). The majority of the PPS group tumours were removed using a transcervical or transcervical–transparotid approach. PPS group tumours were larger (P < 0.001), and tumour spill occurred more frequently in this group (benign tumours: P = 0.002; malignant tumours: P = 0.033). Complication rates did not differ between the PPS and non-PPS groups. A transcervical or transcervical–transparotid approach is the preferred method for the management of deep lobe parotid tumours that occupy the PPS in our practice. Tumour spill occurred more frequently in the PPS group, which is most probably due to the larger tumour size and more complex accessibility.