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*

OBJECTIVEThe pathologic slides and clinical data of 119 patients with mucoepidermoid carcinoma (MEC) of salivary glands were reviewed. All patients underwent surgical therapy in Department of Oral and Maxillofacial Surgery, College of Stomatology, Fourth Military Medical University. The postoperative overall observed survival rates and specific survival rates were statistically caculated, and the correlative clinicopathologic factors influencing the prognosis were evaluated.

METHODSStatistical analysis was performed using the SPSS 10.0 software. The survival rates were obtained by the Kaplan-Meier method. The clinicopathologic parameters were evaluated using log rank test (univariate analysis) and Cox proportional hazards regression model (multivariate analysis).

RESULTSThe overall observed survival rates of this group were 92.53%, 87.52% and 85.39% at 5, 10 and 15 years respectively after surgical therapy. Univariate analysis demonstrated that the factors correlated with lower in survival rates were patient's age (> or = 40 years), advanced clinical stage (TNM III, IV stage) and the poorly differentiated tumors (P < 0.05). The survival rates of male patients with MEC in the major salivary glands were significantly lower than those of female patients (P = 0.008). The degree of differentiation, TNM stage and preoperative symptoms were three important prognostic factors that were selected into the Cox proportional hazards regression model.

CONCLUSIONSMost patients with highly differentiated MEC in salivary glands had a favorable outcome after receiving adequate surgical treatment. The degree of differentiation and the TNM stage of MEC in the salivary glands are two useful factors to evaluate the prognosis of these neoplasms.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Carcinoma, Mucoepidermoid ; mortality ; pathology ; surgery ; Child ; Female ; Humans ; Male ; Middle Aged ; Prognosis ; Proportional Hazards Models ; Salivary Gland Neoplasms ; mortality ; pathology ; surgery ; Survival Rate ; Young Adult