[A Case of Pulmonary Nontuberculous Mycobacterial Infection Accompanied with Intraductal Papillary Mucinous Neoplasm].

An 87-year-old woman presented to the emergency department with left thigh pain, and sciatic nerve pain was diagnosed. A chest CT scan showed bronchiectasis and tree-in buds and an acid-fast stain test of gastric juice was positive; further, M. avium-PCR of sputum and culture results were positive leading to a diagnosis of pulmonary nontuberculous mycobacterial infection(NTM). Abdominal CT showed dilatation of the main pancreatic duct and a multifocal cystic tumor in the pancreatic tail, which was found to be complicated with an intraductal papillary mucinous tumor(IPMN).

[A Case of Perforated Low-Grade Appendiceal Mucinous Neoplasm Diagnosed During Appendectomy].

A 46-year-old female presented persistent right lower abdominal pain for 4 days. Computed tomography revealed an enlarged appendix with a surrounding low-attenuation mass. The patient was diagnosed with appendiceal abscess-forming appendicitis and initially treated with antibiotics. However, owing to the manifestation of nausea as a side effect, laparoscopic appendectomy was performed 3 days after the initial consultation. Intraoperative examination revealed mucinous material on the surface of the appendix and within the abdominal cavity, leading to the decision to perform an appendectomy with partial cecum resection and excision of the omentum with mucinous deposits. Pathological examination confirmed the diagnosis of a perforating low-grade appendiceal mucinous neoplasm and pseudomyxoma peritonei. The patient was subsequently referred to a specialized center for ongoing management, and at 9 months postoperatively, surveillance is being conducted. Low-grade appendiceal mucinous neoplasms can progress to pseudomyxoma peritonei through perforation; however, an optimal treatment approach has not yet been established. In particular, patients in advanced stages of the disease often require challenging management decisions. This case is reported along with a review of the literature to provide further guidance.

Pilot Experiment on Non-Invasive Non-Thermal Disintegration of Human Mucinous Breast Carcinoma Ex Vivo Using Boiling Histotripsy.

We present the results of a pilot study demonstrating the feasibility of non-invasive non-thermal disintegration of human mucinous carcinoma of the breast ex vivo using sequences of high-intensity focused ultrasound pulses in boiling histotripsy regimen. The target volume was sonicated by focusing ultrasound pulses (n=20) of 1.5 MHz frequency, 10-msec duration and 1-sec pulse repetition period, 517 W acoustic power within the pulse, and 103 MPa shock front amplitude at the focus into each node of a volumetric grid 4×4×1 mm. Sonication was visualized and controlled using B-mode ultrasound imaging, total time of the treatment was 21 min. Histological hematoxylin and eosin and Masson's trichrome staining revealed the absence of tumor elements in the treated region confirming destruction of cancer cells and their nuclei after boiling histotripsy procedure.

Mucinous tubular and spindle renal cell carcinoma revealed by a trauma of the kidney: a case report.

BACKGROUND: Mucinous tubular and spindle cell carcinoma is a rare renal tumor. It has been recognized as a distinct entity in the 2004 World Health Organization tumor classification. Since then, several dozen of these tumor have been reported with additional complementary morphologic characteristics, immunohistochemical profile, and molecular genetic features that have further clarified its clinicopathologic aspects. CASE PRESENTATION: We report the case of a 52-year-old male African patient who was found to have a mucinous tubular and spindle renal cell carcinoma on a nephrectomy specimen for a severe kidney trauma. CONCLUSIONS: This tumor has a histological spectrum ranging from low to high grade, which includes sarcomatoid differentiation that can confer the tumor an aggressive clinical course.

[A Case of Primary Adenocarcinoma Mucinous Subtype of the Bladder].

A 48-year-old man who presented with asymptomatic gross hematuria in July 202X had been followed up without treatment. In January 202X, he was referred to our department due to the exacerbation of his hematuria. Contrast-enhanced magnetic resonance imaging revealed bladder cancer suggested bilateral seminal vesicle and prostate invasion, and enlarged right internal and external iliac lymph nodes. The pathological diagnosis was mucinous bladder adenocarcinoma. Prostate biopsy results were negative. Upper and lower gastrointestinal examinations were unremarkable. We suspected bladder cancer cT4aN2M0. In March 202X＋1, the patient underwent robotic-assisted laparoscopic total bladder resection, pelvic lymph node dissection, and intracorporeal urinary tract modification (ileal conduit creation). The final diagnosis was primary mucinous adenocarcinoma pT4aN2M0 of the bladder. Given the heightened risk of recurrence, the patient was administered a three-month course of oxaliplatin and capecitabine (XELOX) as adjuvant postoperative chemotherapy. The patient remains free of progression at 8 months postoperatively. Adenocarcinoma of the bladder is an exceedingly rare entity, with no established chemotherapeutic protocols. Primary mucinous adenocarcinoma of the bladder is even more exceptional. Presently, only regimens similar to those for colorectal cancer or adenocarcinoma of unknown primary, including 5-fluorouracil, are considered. In our particular case, we elected to pursue XELOX therapy, aligning with the principles governing the management of colorectal cancer.

Mucocoele of the appendix.

Introduction: Mucocoele of the appendix occurs in 0.2-0.7% of people in the world without any well-defined clinical symptoms. It occurs when there is an accumulation of mucous in the lumen of the appendix. Case Presentation: We present three cases: a 48-year-old male admitted to the emergency room with a one-day history of right iliac fossa pain. Abdominal examination was suggestive of acute appendicitis. The initial abdominal computerised tomography scan was reported as being unremarkable. At surgery, a firm tumour of the appendix was found, and a limited right hemicolectomy was done. Histopathology confirmed a mucocoele of the appendix with borderline mucinous histology.The second case is a 63-year-old man who presented with a one-year history of abdominal distension and weight loss. Previous abdominal ultrasound was suggestive of liver cirrhosis with significant ascitic fluid. Abdominal magnetic resonance imaging found an appendix mucocoele with infiltration of the omentum and scalloping of the liver surface suggestive of pseudomyxoma peritonei. A percutaneous biopsy of the omental mass confirmed metastatic mucinous adenocarcinoma of the appendix.The third case is a 68-year-old man who, during an annual medical check-up, had an incidental finding of a cystic right iliac fossa mass on ultrasound, confirmed on abdominopelvic computerised tomography scan to be an appendix mucocele. He had laparoscopic appendicectomy. The histopathological diagnosis confirmed a mucinous cystadenoma of the appendix. Conclusion: Preoperative diagnosis of appendiceal mucocoele is difficult and commonly discovered intraoperatively. The prognosis is good for the histologically benign type, but it is poor when malignant or peritoneal lesions are present. Funding: None declared.

Nomogram for predicting outcomes in elderly women with mucinous breast cancer: A retrospective study combined with external validation in southwest China.

OBJECTIVE: Mucinous breast cancer (MBC) is a kind of breast cancer (BC), which is rare in clinic, mainly for women, because of the low incidence rate, so there is no unified standard treatment protocol. Elderly patients have a poor prognosis due to their combined comorbidities. This study aims to investigate the effect of surgery and chemoradiotherapy on the prognosis of elderly female MBC patients and construct nomograms for predicting the OS and CSS in elderly female MBC patients. METHODS: Data for female MBC patients over 65 years are obtained from the Surveillance, Epidemiology and End Results (SEER) database, patients were divided into two groups: the training set and the validation set. External validation data of the prediction model were provided by Kunming Hospital of Traditional Chinese Medicine. We used Cox regression modeling, which was used to identify independent risk factors affecting patient prognosis. After avoiding confounding bias according to the multifactorial Cox regression model, we used these screened statistically significant results to construct column-line plots. The performance of the model was tested using the consistency index (c-index), the calibration curve, and the area under the operating characteristic curve of the receiver (AUC). Subsequently, we used decision curve analysis (DCA) to examine the potential clinical value of our nomograms. RESULTS: A total of 8103 elderly MBC female patients were extracted from the database SEER and were assigned to the training and validation set, randomly. A total of 83 patients from Kunming Hospital of Traditional Chinese Medicine were used in the external verification set. After multifactorial Cox regression analysis, we found that age, race, T-stage, M-stage, surgical approach, radiotherapy, and tumor size were independent risk factors for OS in elderly MBC patients. Similarly, independent risk factors of CSS included age, marital status, N stage, M stage, surgical approach, chemotherapy, and tumor size. The C-index for the OS training, validation, and external verification set were 0.731 (95%CI 0.715-0.747), 0.738 (95%CI 0.724-0.752), and 0.809 (95%CI 0.731-0.8874). The C-index of the training set, the validation set, and external verification set for CSS were 0.786 (95%CI 0.747-0.825), 0.776 (95%CI 0.737-0.815), and 0.84 (95%CI0.754-0.926), respectively. The AUC, calibration curves and DCA also showed good accuracy. CONCLUSIONS: In this study, we construct a new nomogram to predict the prognosis of elderly patients with MBC. The nomograms have undergone internal and external validation and have been confirmed to have good clinical applicability. At the same time, we found that for elderly female MBC patients, surgery and radiotherapy significantly benefit their survival, but chemotherapy is not conducive to patient survival.

Predictive value of circulating lymphocyte subsets and inflammatory indexes for neoadjuvant chemoradiotherapy response in rectal mucinous adenocarcinoma patients: A machine learning approach.

INTRODUCTION: In this study, we aimed to evaluate the predictive value of circulating lymphocyte subsets and inflammatory indexes in response to neoadjuvant chemoradiotherapy (NCRT) in patients with rectal mucinous adenocarcinomas (MACs). METHODS: Rectal MAC patients who underwent NCRT and curative resection at Fujian Medical University Union Hospital's Department of Colorectal Surgery between 2016 and 2020 were included in the study. Patients were categorized into good and poor response groups based on their pathological response to NCRT. An independent risk factor-based nomogram model was constructed by utilizing multivariate logistic regression analysis. Additionally, the extreme gradient boosting (XGB) algorithm was applied to build a machine learning (ML)-based predictive model. Feature importance was quantified using the Shapley additive explanations method. RESULTS: Out of the 283 participants involved in this research, 190 (67.1%) experienced an unfavorable outcome. To identify the independent risk factors, logistic regression analysis was performed, considering variables such as tumor length, pretreatment clinical T stage, PNI, and Th/Tc ratio. Subsequently, a nomogram model was constructed, achieving a C-index of 0.756. The ML model exhibited higher prediction accuracy than the nomogram model, achieving an AUROC of 0.824 in the training set and 0.762 in the tuning set. The top five important parameters of the ML model were identified as the Th/Tc ratio, neutrophil to lymphocyte, Th lymphocytes, Gross type, and T lymphocytes. CONCLUSION: Radiochemotherapy sensitivity is markedly influenced by systemic inflammation and lymphocyte-mediated immune responses in rectal MAC patients. Our ML model integrating clinical characteristics, circulating lymphocyte subsets, and inflammatory indexes is a potential assessment tool that can provide a reference for individualized treatment for rectal MAC patients.

Response of various histological types of locally advanced rectal cancer to neoadjuvant multimodality therapy.

Objectives: To determine the response of various histological types of locally advanced rectal cancer to neoadjuvant multimodality therapy. METHODS: The non-randomised, quasi-experimental retrospective cohort study was conducted at the Combined Military Hospital, Rawalpindi, Pakistan, and comprised data of patients treated between January 1, 2020, to September 30, 2021. The data retrieved related to histologically proven and locally advanced rectal cancer patients aged 18-70 years receiving neoadjuvant chemoradiotherapy. Radiotherapy dose was 45 gray to pelvis with a boost to gross tumour of 5.4 gray in 3 fractions by using volumetric arc therapy concurrently with capecitabine 625mg/m² daily. A magnetic resonance imaging scan of pelvis with contrast was done at 5-10 weeks before surgery. Histological response to neoadjuvant treatment of various histological types was evaluated using the Rectal Cancer Regression Grade. Data was analysed using SPSS 22. RESULTS: Of the 182 patients evaluated, 108(59.34%) were included; 64(59.3%) males and 44(40.7%) females. The overall mean age was 45.4±5.2 years. Regression status was grade 1 in 24(22%) patients, grade 2 in 43(40%) and grade 3 in 41(38%) (p=0.074). There were 12(11.11%) patients with signet ring cell and 10(83.3%) showed pathological tumour regression. There were 17(15.74%) patients with mucinous variant, and 12(70.5%) had tumour regression. There were 79(73.15%) patients with adenocarcinoma, and 59(74.6%) of them showed tumour regression. . CONCLUSIONS: There was less tumour regression in mucinous and signet ring cell variants of adenocarcinoma. Modification and intensification of neoadjuvant therapy may be required in such histologies.

Establishment and verification of novel TNM staging system for lung mucinous adenocarcinoma.

BACKGROUND: Lung adenocarcinoma is a high-mortality rate cancer. Within this category, Lung mucinous adenocarcinoma (LMAC) is a rare and distinct subtype of lung adenocarcinoma necessitating further investigation. The study was launched to compare the difference of survival features between LMAC and lung non-mucinous adenocarcinoma (LNMAC) and to investigate the significance and demand for developing a new staging system tailored to LMAC. METHODS: This retrospective study assessed the suitableness of the current staging system for LMAC. It compared the overall survival (OS) between LMAC and LNMAC from 2004 to 2020 (LNMAC: 160,387; LMAC: 6,341) and instituted a novel classification framework for LMAC based on US population. Verification group consisting of patients from two Chinese medical centers from 2010 to 2018 (n = 392) was set to ascertain the applicability of this novel system. The primary endpoint was OS. To minimize the bias, propensity score match (PSM) was employed. Survival analysis and Log-rank test were executed to explore the survival features of LMAC. RESULTS: The results indicated that the existed staging system was not suitable for LMAC. Patients diagnosed with LMAC exhibited a superior OS compared to those with LNMAC in stage IA2 (P < 0.0001), IA3 (P < 0.0001), IB (P = 0.0062), IIA (P = 0.0090), IIB (P = 0.0005). In contrast, a worse OS in stage IVA (P = 0.0103) was found in LMAC patients. The novel classification system proposed for LMAC proved to be highly applicable and demonstrated substantial efficacy, as confirmed by the verification group. CONCLUSION: The newly established classification system was more effective for LMAC, but it necessitates large-scale verification to confirm its applicability and reliability.

Comprehensive analysis of clinical data and radiomic features from contrast enhanced CT for differentiating benign and malignant pancreatic intraductal papillary mucinous neoplasms.

The primary aim of this investigation was to leverage radiomics features derived from contrast-enhanced abdominal computed tomography (CT) scans to devise a predictive model to discern the benign and malignant nature of intraductal papillary mucinous neoplasms (IPMNs). Radiomic signatures were meticulously crafted to delineate benign from malignant IPMNs by extracting pertinent features from contrast-enhanced CT images within a designated training cohort (n = 84). Subsequent validation was conducted with data from an independent test cohort (n = 37). The discriminative ability of the model was quantitatively evaluated through receiver operating characteristic (ROC) curve analysis, with the integration of carefully selected clinical features to improve the comparative analysis. Arterial-phase images were utilized to construct a model comprising 8 features for distinguishing between benign and malignant cases. The model achieved an accuracy of 0.891 [95% confidence interval (95% CI), 0.816-0.996] in the cross-validation set and 0.553 (95% CI 0.360-0.745) in the test set. Conversely, employing 9 features from the venous-phase resulted in a model with a cross-validation accuracy of 0.862 (95%CI 0.777-0.946) and a test set accuracy of 0.801 (95% CI 0.653-0.950).Integrating the identified clinical features with imaging features yielded a model with a cross-validation accuracy of 0.934 (95% CI 0.879-0.990) and a test set accuracy of 0.904 (95% CI 0.808-0.999), thereby further improving its discriminatory ability. Our findings distinctly illustrate that venous-phase radiomics features eclipse arterial-phase radiomic features in terms of predictive accuracy regarding the nature of IPMNs. Furthermore, the synthesis and meticulous screening of clinical features with radiomic data significantly increased the diagnostic efficacy of our model, underscoring the pivotal importance of a comprehensive and integrated approach for accurate risk stratification in IPMN management.

Urinary microRNA-210-3p as a novel and non-invasive biomarker for the detection of pancreatic cancer, including intraductal papillary mucinous carcinoma.

BACKGROUND: This study aims to explore novel microRNAs in urine for screening and predicting clinical characteristics in pancreatic cancer (PC) patients using a microRNA array-based approach. METHODS: We used the Toray® 3D-Gene microRNA array-based approach to compare urinary levels between PC patients and healthy volunteers. RESULTS: (1) Four oncogenic microRNAs (miR-744-5p, miR-572, miR-210-3p, and miR-575) that were highly upregulated in the urine of PC patients compared to healthy individuals were identified by comprehensive microRNA array analysis. (2) Test-scale analysis by quantitative RT-PCR for each group of 20 cases showed that miR-210-3p was significantly upregulated in the urine of PC patients compared to healthy individuals (P = 0.009). (3) Validation analysis (58 PC patients and 35 healthy individuals) confirmed that miR-210-3p was significantly upregulated in the urine of PC patients compared to healthy individuals (P < 0.001, area under the receiver operating characteristic curve = 0.79, sensitivity: 0.828, specificity: 0.743). We differentiated PC patients into invasive ductal carcinoma (IDCa) and intraductal papillary mucinous carcinoma (IPMC) groups. In addition to urinary miR-210-3p levels being upregulated in IDCa over healthy individuals (P = 0.009), urinary miR-210-3p levels were also elevated in IPMC over healthy individuals (P = 0.0018). Urinary miR-210-3p can differentiate IPMC from healthy individuals by a cutoff of 8.02 with an AUC value of 0.762, sensitivity of 94%, and specificity of 63%. (4) To test whether urinary miR210-3p levels reflected plasma miR-210-3p levels, we examined the correlation between urinary and plasma levels. Spearman's correlation analysis showed a moderate positive correlation (ρ = 0.64, P = 0.005) between miR-210-3p expression in plasma and urine. CONCLUSIONS: Urinary miR-210-3p is a promising, non-invasive diagnostic biomarker of PC, including IPMC. TRIAL REGISTRATION: Not applicable.

Low-grade appendiceal mucinous neoplasms: Histomorphological spectrum in a tertiary care hospital.

BACKGROUND: Low-grade appendiceal mucinous neoplasms (LAMNs) are benign non-invasive epithelial proliferations of the appendix. These usually present clinically as mucoceles and these rarely exceed 2 cm in diameter. Lesions confined to the lumen are labelled as LAMN; however those in which mucin spreads outside the peritoneum are labeled as pseudomyxoma peritonei (PMP). AIMS AND OBJECTIVE: A retrospective study was conducted over a period of three years and all cases of appendectomies were studied. Twelve cases of LAMN were identified, which is a diagnostic dilemma for the pathologists and clinicians. RESULTS: LAMN was identified based on the histopathological features. Out of the 12 cases, 9 were classified as LAMN and 3 as appendiceal neoplasm with PMP. There was villous or flat proliferation of epithelial lining, loss lymphoid aggregates, and dissecting mucin within muscularis. CONCLUSION: LAMNs are rare neoplasms of the appendix, with clinical presentation similar to acute appendicitis. Mucinous collections within the appendiceal wall should be extensively searched for mucosal changes and, if found, should prompt a careful search for pushing invasion of LAMNs. A thorough and vigilant gross examination can be of great help. Appendicectomy is the treatment of benign and grossly intact mucinous neoplasm.

LAMN port-site metastasis after laparoscopic oophorectomy for a presumed ovarian tumour treated with CRS and HIPEC.

Low-grade appendiceal mucinous neoplasm (LAMN) may culminate as a mucin-secreting disease known as pseudomyxoma peritonei (PMP). Once the diagnosis of LAMN and PMP is made, cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS and HIPEC) are indicated.Herein, we present a female patient in her 50s who was diagnosed with an ovarian mass for which she underwent laparoscopic oophorectomy. As the pathology of the ovary showed a tumour of gastrointestinal origin, she then underwent CRS and HIPEC with a final pathology of LAMN. Six weeks later, a mucinous lesion confined to the abdominal wall was detected on a postoperative CT. Suspected for port-site metastasis at the laparoscopic trocar site, we treated this lesion using the same principles of treatment as the intra-abdominal disease. The abdominal wall mass was surgically resected, and the cavity created was irrigated with mitomycin C. On 30 months of follow-up, the patient had no evidence of disease.

Optimization of Endoscopic Ultrasound Characteristics in the Diagnosis of Malignant Intraductal Papillary Mucinous Neoplasm.

OBJECTIVES: Endoscopic ultrasound (EUS) is an excellent diagnostic tool that provides high-resolution images of pancreatic cystic lesions. However, its role in the diagnosis of malignant intraductal papillary mucinous neoplasm (IPMN) remains limited and unclear. We aimed to determine the usefulness of this modality for such diagnosis. METHODS: Overall, 246 patients who underwent EUS for IPMN after computed tomography (CT)/magnetic resonance imaging (MRI) from April 2018 to June 2021 were followed up until March 2022. We assessed the added value of performing EUS after CT or MRI for diagnosing malignant IPMN, using receiver operating characteristic curve analysis. Walls as thick as 2 mm were considered thickened in this study if they were highly uneven. RESULTS: EUS clearly enhanced accuracy in identifying enhancing nodules and thickened walls. The areas under the receiver operating characteristic curve and corresponding 95% confidence intervals were 0.655 (0.549-0.760) and 0.566 (0.478-0.654) upon CT/MRI but 0.853 (0.763-0.942) and 0.725 (0.634-0.817) when observed using EUS. The combination of nodule size, thickened wall, and main duct size yielded the highest area under the receiver operating characteristic curve (0.944 [0.915-0.973]). CONCLUSIONS: EUS more accurately detects malignant IPMN, as uneven wall thickening and certain nodules cannot be identified with CT/MRI.

[Primary mucinous gland lesions of fallopian tube: a clinicopathological analysis of fourteen cases].

Objective: To investigate the clinical and pathological characteristics of primary mucinous gland lesions of the fallopian tubes. Methods: The clinical data, pathomorphological characteristics and immunophenotype of 14 cases of primary mucinous gland lesions of the fallopian tube diagnosed at Obstetrics and Gynecology Hospital of Fudan University from 2015 to 2023 were analyzed retrospectively. In addition, a comprehensive review of relevant literature was conducted. Results: The age of 14 patients ranged from 53 to 83 years, with an average of 65 years. Among them, 13 cases exhibited unilateral involvement while one case showed bilateral presentation. Nine cases were mucinous metaplasia of the fallopian tube, four cases were invasive mucinous adenocarcinoma and one case was mucinous carcinoma in situ. Morphologically, mucinous metaplasia of the fallopian tube was focal, with or without inflammation. The cells of mucinous adenocarcinoma or mucinous carcinoma in situ exhibited characteristics indicative of gastrointestinal differentiation. Immunohistochemical analysis revealed diffuse positive expression of CK7, and negative expression of SATB2. CDX2 demonstrated positive staining in two cases. One case exhibited diffuse and strongly positive mutant expression of p53, whereas the remaining cases displayed wild-type expression. MUC6 showed diffuse or focally positive staining in mucinous gland lesions characterized by gastric differentiation. Some cases of mucinous adenocarcinoma of fallopian tube were subject to AB-PAS staining, resulting in red to purple cytoplasmic staining. Conclusions: Primary mucinous lesions of the fallopian tube are exceedingly uncommon. All cases of mucinous adenocarcinoma of fallopian tubes in this study exhibit the morphology and immunohistochemical characteristics of gastrointestinal differentiation. Mucinous metaplasia of the fallopian tube is a benign lesion of incidental finding, which is closely related to inflammation or gastric differentiation. Mucinous lesions of cervix, ovary and digestive tract are excluded in all patients, confirming the independent existence of mucinous lesions within fallopian tubes.

[Correlation between common driver gene variations and clinicopathological typing in lung adenocarcinoma].

Objective: To correlate the common driver gene variations in primary lung adenocarcinoma with their clinical characteristics and histopathological subtypes. Methods: There were 4 995 cases of primary lung adenocarcinoma diagnosed at Weifang People's Hospital of Shandong Province from January 2015 to December 2021 which were retrospectively analyzed. Among them 1 983 cases were evaluated for their histopathological subtype; 3 012 were analyzed for the correlation of their histopathological subtypes and corresponding driver gene variations, including invasive non-mucinous adenocarcinoma (INMA) and invasive mucinous adenocarcinoma (IMA), and morphologically, poorly-differentiated, moderately-differentiated and well-differentiated adenocarcinomas. Next-generation sequencing was used to detect variations in EGFR, KRAS, ALK, RET, ROS1, MET, HER2, or BRAF driver genes. Results: There were 2 384 males and 2 611 females. EGFR and ALK variations were more commonly found in female patients aged 60 years or older, with EGFR mutation rate in clinical stage Ⅰ (25.80%) significantly higher than in other stages (P<0.05). KRAS mutations were more commonly detected in male smokers aged 60 years or older, HER2 mutations were more commonly in patients younger than 60 years, and RET mutations were more commonly in non-smokers (all P<0.05). No correlation was found between ROS1, MET, and BRAF gene variations and their clinical characteristics (P>0.05). For the histopathological subtypes, among the 1 899 cases of acinar adenocarcinoma, EGFR mutation rate was the highest (67.30%) compared to the other genes. Exon 21 L858R and exon 19 del were the main mutation sites in IMA and INMA, with a higher mutation rate at exon 20 T790M (11.63%) in micropapillary adenocarcinoma. In IMA, KRAS had the highest overall mutation rate (43.80%), with statistically significant difference in mutation rates of exon 2 G12D and exon 2 G12V in acinar adenocarcinoma, solid, and IMA (P<0.05). KRAS mutation at various sites were higher in poorly differentiated groups compared to moderately- and well-differentiated groups (P<0.05). HER2 mutations were more commonly observed in acinar adenocarcinoma, papillary, and micropapillary adenocarcinoma of INMA. BRAF mutation was higher in micropapillary adenocarcinoma compared with other types (P<0.05). Conclusions: Variations in EGFR, ALK, KRAS, HER2, and RET in primary lung adenocarcinoma are associated with patients' age, smoking history, and clinical stage, and driver gene mutations vary among different histopathological subtypes. EGFR mutations are predominant in INMA, while KRAS mutations are predominant in IMA.