Epithelial-myoepithelial carcinoma (EMC) is a rare salivary gland tumor that is histologically characterized by biphasic tubular structures composed of inner ductal and outer clear myoepithelial cells. Because of its histologic variety, it is sometimes challenging to make an accurate diagnosis, and useful ancillary tests are essential for this purpose. We investigated 87 cases of EMC arising in the major and minor salivary glands and seromucinous glands in the nasal cavity or bronchus to describe the histologic features and mutation status of selected key oncogenes. Classic EMC accounted for 40.2% of all cases. Other cases showed various growth patterns and cytologic features in addition to the typical histology; cribriform patterns, a basaloid appearance, and sebaceous differentiation were relatively common (17.2% to 18.4%), whereas oncocytic/apocrine, papillary-cystic, double-clear, squamous, psammomatous, Verocay-like, and high-grade transformation were rare. HRAS mutations were found in 82.7% of EMCs and were concentrated in codon 61. There was no significant correlation between the HRAS mutation status and the histology. No EMC ex pleomorphic adenoma cases had HRAS mutations. PIK3CA and/or AKT1 mutations were the second most frequent mutations (20.7%, 6.5%, respectively) and almost always cooccurred with HRAS mutations. It is noteworthy that the HRAS mutation was not identified in any salivary gland tumor entities manifesting EMC-like features, including adenoid cystic carcinoma, pleomorphic adenoma, basal cell adenoma/adenocarcinoma, and myoepithelial carcinoma. We conclude that HRAS mutations are a frequent tumorigenic gene alteration in EMC, despite its histologic diversity. This study provides further insight into strategies for diagnosing EMC and discriminating it from its mimics.

Although immune-checkpoint inhibitors (ICIs) are effective against various cancers, little is known regarding their role in salivary gland carcinoma (SGC) treatment. Therefore, we evaluated the efficacy and safety of nivolumab monotherapy in patients with recurrent and/or metastatic SGC. In this multicentre retrospective study, nivolumab (240 mg) was administered every 2 weeks. The overall response rate (ORR), progression-free survival (PFS), overall survival (OS), and safety were examined; the correlation between treatment outcomes and clinicopathological factors was analysed. Twenty-four patients were enrolled; the most common histopathology was salivary duct carcinoma. Eleven tumours were PD-L1-positive; no tumour was microsatellite instability-high. The ORR was 4.2%, and the median PFS and OS were 1.6 and 10.7 months, respectively. One patient continued nivolumab for 28 months without disease progression. One patient showed grade 4 increase in creatine phosphokinase levels and grade 3 myositis. Biomarker analysis revealed significantly increased OS in patients with performance status of 0; modified Glasgow prognostic score of 0; low neutrophil-to-lymphocyte ratio, lactate dehydrogenase, and C-reactive protein; and high lymphocyte-to-monocyte ratio and in patients who received systemic therapy following nivolumab. Although nivolumab’s efficacy against SGC was limited, some patients achieved long-term disease control. Further studies are warranted on ICI use for SGC.

Both preoperative and postoperative chemoradiation therapy adversely affects continence and evacuation in patients with colonic J-pouch. Because radiation-induced damage to the normal tissues is known to be cumulative over time, long-term progressive dysfunction of the anal sphincter and neorectum are causes of concern. Consideration should be given to excluding the anal canal from the field of irradiation in patients with Stage II and III rectal cancer, whenever a sphincter-preserving procedure is planned.

This study was conducted to determine whether stapled ileal pouch-anal canal anastomosis (IACA) preserving the anal transitional zone (ATZ) or hand-sewn ileal pouch-anal anastomosis with mucosectomy (IPAA) is more beneficial in achieving disease eradication and better postoperative function. IACA was performed in 10 patients with ulcerative colitis (UC) and 10 patients with familial adenomatous polyposis (FAP), 15 of whom were examined proctoscopically. IPAA was performed in 4 patients with UC and 8 patients with FAP. The mean maximum resting pressure (MRP) was 55 mmHg in the IACA group and 34 mmHg in the IPAA group (P < 0.01). The anorectal inhibitory reflex was positive in 18 patients (90%) from the IACA group and 5 (42%) from the IPAA group (P < 0.05). The pre- and postoperative MRPs were 61 mmHg and 55 mmHg, respectively, in the IACA group vs 63 mmHg and 34 mmHg, respectively, in the IPAA group (P < 0.01). Whereas 16 (80%) of the 20 IACA patients could discriminate feces from gas, only 4 (33%) of the 12 IPAA patients could (P < 0.05). The mean observation period was 2.3 years, the mean length of the columnar cuff was 2.8 cm, and no case of dysplasia or adenoma was seen. Postoperative function is more favorable following IACA than following IPAA, both physiologically and symptomatically. However, long-term surveillance of the residual mucosa is necessary before making a final recommendation.

Preservation of the rectoanal inhibitory reflex correlated with a decrease in the incidence of nocturnal soiling after double-stapled ileoanal reservoir construction.