BACKGROUND: Primary pulmonary mucoepidermoid carcinoma (PMEC) is an exceedingly rare malignancy originating from bronchial submucosal glands, accounting for <0.2% of lung cancers. Histologically characterized by a triphasic composition of mucinous, epidermoid, and intermediate cells, PMEC is classified into low-grade (favorable prognosis) and high-grade (aggressive behavior) subtypes. This study aimed to investigate the clinicopathological characteristics and prognostic indicators of PMEC. METHODS: Clinicopathological, radiological, molecular, and survival data from 26 PMEC patients were retrospectively analyzed, including immunohistochemical profiles and MAML2 rearrangement status, supplemented by literature review. RESULTS: The cohort comprised 14 males and 12 females (mean age: 55.6 years). Eight patients (30.8%) were smokers, and 19 (73.1%) presented with symptoms. Central tumors predominated (n=19, 73.1%) versus peripheral lesions (n=7, 26.9%). Computed tomography (CT) imaging consistently revealed hypo-to-isodense masses/nodules. Pathologically, 19 cases were low-grade and 7 high-grade. Immunohistochemically, the tumor cells were positive for CK7, P40, P63 and CK5/6, and the Ki-67 index ranged from 2% to 70%. MAML2 rearrangement was detected in 52.4% (11/21) of tested cases. Clinical staging distribution: stage I (n=14), stage II (n=8), stage III (n=3), stage IV (n=1). Treatment modalities: radical surgery alone (n=13), surgery with adjuvant chemotherapy (n=11), chemoradiotherapy (n=1), and conservative management (n=1). With a median follow-up of 57 months, 6 patients (23.1%) died. Prognostic analysis demonstrated: (1) Significantly inferior survival in high-grade versus low-grade groups (P<0.05); (2) Lymph node metastasis, advanced stage, Ki-67>20%, and high-grade histology significantly correlated with reduced overall survival (P<0.05); (3) Lymph node metastasis constituted an independent poor prognostic factor (HR=12.73, 95%CI: 1.22-132.96). CONCLUSIONS PMEC exhibits distinct clinicopathological features, with MAML2 rearrangement present in approximately half of cases. Lymph node metastasis, advanced stage, high Ki-67 proliferation index, and high-grade histology are key determinants of poor prognosis, with lymph node metastasis serving as an independent risk factor.
Humans ; Male ; Female ; Middle Aged ; Carcinoma, Mucoepidermoid/mortality* ; Lung Neoplasms/mortality* ; Trans-Activators/genetics* ; Prognosis ; Adult ; Gene Rearrangement ; Aged ; Retrospective Studies ; Transcription Factors/genetics* ; DNA-Binding Proteins/genetics*

A 57-year-old woman with a 2-year history of a left infra-auricular mass with no associated symptoms presented with a 6.0 cm ´ 4.0 cm ´ 3.0 cm firm, non-tender, movable mass. No imaging was done. Fine needle aspiration biopsy (FNAB) revealed sheets of epithelial cells that had abundant dense grayish-blue cytoplasm in a mucinous background with abundant lymphocytes (Figure 1), suggestive of salivary gland neoplasm with oncocytic or oncocytoid features (Category IVB, Salivary Gland Neoplasm of Uncertain Malignant Potential).Total parotidectomy revealed a 4.3 X 3.2 X 3.0 cm deep lobe lesion with a tan-grey to dark brown, smooth and dull external surface. Cut sections showed a cream-white to pink, lobulated, heterogenous cut surfaces. Microscopically, the lesion was unencapsulated with poorly demarcated borders. The neoplastic cells were arranged in haphazard sheets and surrounded by abundant lymphocytes. The tumor cells had abundant eosinophilic and granular cytoplasm compatible with oncocytes with mild to moderate nuclear atypia. There were occasional cystic spaces that contained mucin though mucocytes were not readily apparent. (Figure 2) Necrosis, perineural and lymphovascular space invasion or anaplasia were not evident.
Carcinoma, Mucoepidermoid ; Salivary Gland Neoplasms ; Parotid Gland

Humans ; Carcinoma, Mucoepidermoid/pathology* ; Breast/pathology*

Humans ; Carcinoma, Mucoepidermoid/pathology* ; Thyroid Neoplasms/pathology* ; Eosinophilia/pathology*

Carcinoma, Mucoepidermoid/surgery* ; Child ; Humans ; Lung/pathology* ; Lung Neoplasms/surgery*

Objective: To study the clinicopathologic and genetic features of papillary cystic low-grade mucoepidermoid carcinoma (LG-MEC) and cystadenoma. Methods: A retrospective review was performed on salivary gland tumor patients with papillary cystic architecture who presented to department of oral pathology, Peking University School and Hospital of Stomatology between January 2010 and June 2022. Among this cohort, there were 17 males and 17 females with a range age of 23-82 years [(55.6±14.6) years]. Diagnosis was confirmed by histological, immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) analysis. Finally, 15 papillary cystic LG-MEC and 19 cystadenoma patients were included in the present study. All patients were followed clinically and radiologically, and the duration of follow-up ranged from 1 to 141 months. Results: All neoplasms showed papillary proliferation with multilocular or giant cystic tumors. Papillary cystic LG-MEC was characterized by epidermoid cells, intermediate cell and mucous cells with multiple lining-layers. Papillary cystic LG-MEC had mild cellular atypia and a pushing infiltration. Cystadenoma was characterized by cuboidal, columnar and ciliated pseudostratified columnar lining epithelium. Squamous metaplasia, mucinous metaplasia and acidophilic degeneration could also be observed focally in cystadenoma. For IHC staining, papillary cystic LG-MEC showed diffusely and strongly positive for mucin 4 (MUC4) (15/15) and mucin 5 Subtype AC (MUC5AC) (4/15) in the epidermoid cells, intermediate cell and mucous cells. The epidermoid cells and intermediate cells were diffusely positive for p40 and p63. The Ki-67 index was about 10%-15% in LG-MEC. As a contrast, p40 (17/19) and p63 (14/15) were only detected in the basal cells of cystadenoma. Cystadenoma showed focal MUC5AC (4/19)expression and MUC4 (19/19)diffuse expression. In addition, the Ki-67 index was 5%-10% in cystadenoma. The MAML2 gene translocation was detected in 11 LG-MEC patients, but none in cystadenoma. Conclusions: The differential diagnosis points between papillary cystic LG-MEC and cystadenoma included the specific epidermoid cells, intermediate cells and mucus cells in LG-MEC, cell atypia, the pushing-infiltration pattern, diffuse expression of p40 and p63 in the lining epithelium, and a MAML2 gene rearrangement. The molecular test of MAML2 should be recommended to reduce missed LG-MEC diagnoses.
Male ; Female ; Humans ; Carcinoma, Mucoepidermoid/pathology* ; In Situ Hybridization, Fluorescence ; Ki-67 Antigen/genetics* ; Biomarkers, Tumor/analysis* ; Salivary Gland Neoplasms/diagnosis* ; Transcription Factors/metabolism* ; Cystadenoma ; Metaplasia

OBJECTIVE: To investigate the clinicopathological characteristics of micro and mini parotid gland tumors and to provide reference for their clinical diagnosis and treatment. METHODS: Patients with parotid gland tumors treated in the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from December 2012 to April 2020 were selected. Relevant clinical data of the patients with tumor diameter ≤20 mm detected by preoperative CT were collected to analyze the clinicopathological characteristics and prognosis of micro and mini parotid gland tumors. And the collected data were divided into two groups with diameter 11-20 mm and diameter ≤10 mm according to tumor diameter measured by preoperative CT. The clinicopathological differences between the two groups were statistically analyzed. RESULTS: A total of 2 067 patients with primary epithelial parotid gland tumors were collected, and 685 patients with tumor diameter ≤20 mm were examined by CT, accounting for 33.1%. The ratio of male to female patients with micro and mini parotid gland tumors was 1 ∶1.93, the average age was (45.3±13.8) years (12-83 years), and the median course of disease was 12 months (1 week to 30 years). Among them, 635 cases (92.7%) were benign tumors, 50 cases (7.3%) were malignant tumors, and the ratio of benign to malignant was 12.7 ∶1. The most common benign tumor was pleomorphic adenoma, and the most common malignant tumor was mucoepidermoid carcinoma. The micro and mini parotid gland tumors were divided into 11-20 mm group (n=611) and ≤10 mm group (n=74), the clinical characteristics comparison of the two groups of gender ratio, average age, course of di-sease had no statistical difference (P>0.05). In the 11-20 mm diameter group, the percentage of benign and malignant tumor was 92.8% (567/611) and 7.2% (44/611) respectively, and the ratio of benign to malignant tumors was 12.9 ∶1. In the ≤10 mm diameter group, the percentage of benign and malignant tumor was 91.9% (68/74) and 8.1% (6/74) respectively, and the ratio of benign to malignant tumors was 11.3 ∶1. There was no significant difference between the two groups (P>0.05). Fifty patients with malignant tumor were followed up for the median follow-up period of 39.5 months (1-91 months). Local recurrence occurred in 2 patients with one death. The overall 2-year survival rate was 93.7% and the 5-year survival rate was 89.3%. CONCLUSION The majority of micro and mini parotid gland tumors was benign lesion. There was a good prognosis for micro and mini parotid gland carcinoma. Early surgical treatment was recommended for micro and mini parotid gland tumors.
Adenoma, Pleomorphic/surgery* ; Adult ; Carcinoma, Mucoepidermoid/pathology* ; Female ; Humans ; Male ; Middle Aged ; Parotid Gland ; Parotid Neoplasms/surgery* ; Retrospective Studies

Mucoepidermoid carcinoma is a malignant tumor that occurs mainly in the salivary glands of adults and children, but rarely in the esophagus. A surgical resection is the primary treatment for mucoepidermal carcinoma, and the prognosis has been reported to be poor. A 61-year-old man was diagnosed with an esophageal nodule in upper gastrointestinal endoscopy for the purpose of a medical examination without any special symptoms and an endoscopic resection was performed for an accurate diagnosis. An endoscopic mucosal resection was performed using a band ligation for a complete resection and continuous follow-up with no evidence of recurrence or metastasis. The unknown prognosis of endoscopic resection makes it necessary to follow the patient carefully.
Adult ; Carcinoma, Mucoepidermoid ; Child ; Diagnosis ; Endoscopy, Gastrointestinal ; Esophagus ; Follow-Up Studies ; Humans ; Ligation ; Middle Aged ; Neoplasm Metastasis ; Prognosis ; Recurrence ; Salivary Glands

Carcinosarcomas, also known as true malignant mixed tumors, are rare tumors of the salivary gland and are composed of both malignant epithelial and malignant mesenchymal elements. They may occur in pre-existing pleomorphic adenomas or arise de novo. Here we report the first case of carcinosarcoma of the parotid gland composed of mucoepidermoid carcinoma and osteosarcoma. The tumor had originated from the parotid gland and extended into the parapharyngeal space. To the best of our knowledge, there have been no reports on mucoepidermoid carcinoma mixed with osteosarcoma ex pleomorphic adenoma in the parotid gland.
Adenoma, Pleomorphic ; Carcinoma, Mucoepidermoid ; Carcinosarcoma ; Mixed Tumor, Malignant ; Osteosarcoma ; Parotid Gland ; Salivary Glands

Mucoepidermoid carcinoma is a malignant tumor that occurs mainly in the salivary glands of adults and children, but rarely in the esophagus. A surgical resection is the primary treatment for mucoepidermal carcinoma, and the prognosis has been reported to be poor. A 61-year-old man was diagnosed with an esophageal nodule in upper gastrointestinal endoscopy for the purpose of a medical examination without any special symptoms and an endoscopic resection was performed for an accurate diagnosis. An endoscopic mucosal resection was performed using a band ligation for a complete resection and continuous follow-up with no evidence of recurrence or metastasis. The unknown prognosis of endoscopic resection makes it necessary to follow the patient carefully.
Adult ; Carcinoma, Mucoepidermoid ; Child ; Diagnosis ; Endoscopy, Gastrointestinal ; Esophagus ; Follow-Up Studies ; Humans ; Ligation ; Middle Aged ; Neoplasm Metastasis ; Prognosis ; Recurrence ; Salivary Glands