A 15-year-old old Japanese male with a 2-month history of swelling of his left subauricular area was admitted to our department. A thumb-sized, hard mass with mild tenderness was palpated on the left parotid gland. Ultrasonography revealed a well-circumscribed, hypoechoic mass exhibiting heterogeneity in the left parotid gland measuring 1.7 × 1.5 × 1.3 cm. Computed tomography scan revealed a well-circumscribed, solid mass exhibiting slight peripheral enhancement in the left parotid gland. Magnetic resonance imaging revealed a hypointense mass in the left parotid gland on both T1-and T2-weighted images. Clinicoradiologic findings suggested a benign or low-grade malignant parotid tumor. The patient underwent left superficial parotidectomy with adequate safety margins. The facial nerve was identified and preserved. Neither facial paralysis nor tumor recurrence was observed as of 1 year postoperatively. Histologically, the nodule consisted of a vaguely nodular arrangement of variably sized ducts and acini in a hyalinized fibrous background with focal myxoid changes. The ductal/ acinar component exhibited a bilayered arrangement of cuboidal luminal and flattened abluminal cells exhibiting a variety of epithelial proliferative patterns, including micropapillary and cribriform. Areas of oncocyte-like changes with intracellular coarse eosinophilic granules, apocrine-like feature, foamy/vacuolated changes, and clear cells were noted in the proliferating epithelium. Immunohistologically, the luminal cells were positive for gross cystic disease fluid protein-15. The Ki-67 labeling index was 2-3%. The histologic features and immunohistologic profile were consistent with sclerosing polycystic adenosis. Targeted next-generation sequencing of 160 cancer-related genes using the surgical specimen revealed no mutations, including known significant mutations in PTEN, PIK3CA, or PIK3R1.

The aim of the present study was to analyze the clinical characteristics, surgical treatments and clinical outcome of patients with parotid gland tumors and to compare the results with those cited in the literature. A retrospective study was conducted in 140 patients (male, n=77; female, n=63) with parotid gland tumors who underwent parotidectomy at Hokuto Hospital Department of Otolaryngology-Head and Neck Surgery (Obihiro, Japan) between April 2007 and December 2021. Of the 140 patients enrolled, 118 (84.3%) patients had benign tumors, including 63 (45%) patients with pleomorphic adenomas and 43 (30.7%) patients with Warthin tumors, and 22 patients (15.7%) had parotid carcinoma. Comparison of the three groups of patients with parotid gland tumors indicated that pack years as an indicator of smoking status were significantly higher in patients with Warthin tumors than in those with parotid carcinomas (P=0.011) or pleomorphic adenoma (P<0.001). Fine-needle aspiration cytology (FNAC) was non-diagnostic for only 6 (4.3%) of 140 patients. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of FNAC by both conventional smear and liquid-based cytology (LBC) for parotid carcinomas were 70, 99, 93.3, 94.4 and 82.9%, respectively. Among the 22 patients with parotid carcinoma, extended total/total and superficial parotidectomy were performed in 10 (45%) and 11 (50%) cases, respectively. Total and selective neck dissection of the area from level II to I, II and III were performed in 6 (24%) and 7 (32%) patients, respectively. Postoperative radiotherapy (50 Gy) was performed in 15 (68%) patients. The overall survival (OS) and disease-free survival (DFS) rates at 5 years were 51.5 and 76.4%, respectively. Univariate analysis revealed that age >65 years was significantly associated with poorer 5-year OS (P<0.001) and DFS (P<0.001). Multivariate analysis revealed that an age of more than 65 years combined with high-grade histologic malignancy was associated with worse DFS (P=0.02; hazard ratio, 3.628; 95% confidence interval, 1.283-9.514). In conclusion, the clinical characteristics and treatment outcomes of parotid gland tumors were consistent with the results of previous reports. Smoking may be closely related to the pathogenesis of Warthin tumors. LBC potentially provides improved accuracy in FNAC.

A 60-year-old woman presented with a 3-year history of a slow-growing, painless mass in their left parotid gland. Ultrasonography revealed a well-circumscribed, lobulated, hypoechoic mass measuring 19x12x10 mm in the left parotid gland. Computed tomography revealed a well-circumscribed, solid mass with homogeneous enhancement. Fluorodeoxyglucose-positron emission tomography revealed uptake by the tumor but no uptake in other organs, including the nasopharynx. The patient underwent superficial parotidectomy with adequate safety margins and selective neck dissection followed by radiotherapy. No facial paralysis or recurrence of the tumor had been observed as of 20 months post-operation. Histologically, the tumor was composed of sheets of syncytial cancer cells with prominent nucleoli in a dense lymphoplasmacytic background. Epstein-Barr virus (EBV)-encoded RNA in situ hybridization was diffusely positive in the tumor cells. These findings indicated that the tumor was an EBV-associated lymphoepithelial carcinoma. Metastasis, especially from the nasopharynx, was excluded endoscopically and radiologically. Targeted next-generation sequencing of 160 cancer-related genes using the surgical specimen revealed no mutations, including known significant mutations detected in EBV-associated nasopharyngeal carcinoma.

Pleomorphic adenoma is a benign tumor that commonly arises from the major salivary glands, such as the parotid and submandibular glands. However, they rarely originate from the nasal cavity. Herein, we describe the case of a 49-year-old woman who presented with nasal obstruction. Preoperative evaluation revealed a giant pleomorphic adenoma attached to the nasal septum. Transnasal endoscopic removal was successfully performed using a specimen retrieval bag. We performed an endoscopic complete en-bloc resection of a large pleomorphic adenoma in the nasal cavity, using a specimen retrieval bag. There were no complications seen, no local recurrences after 2 years of follow-up, and the patient satisfaction was high. We therefore recommend that this technique of using specimen retrieval bags can be favorably utilized for endoscopic removal of large nasal tumors like pleomorphic adenoma.