Primary clear-cell carcinoma of the lung

Clear cell adenocarcinoma of the lung: a population-based study

BACKGROUND

Clear cell adenocarcinoma of the lung (CCAL) is a rare diagnosis with poorly understood clinicopathological characteristics and disease progression.

METHODS

A population cohort study was conducted using prospectively extracted data from the Surveillance, Epidemiology and End Results database for patients with histological diagnoses of CCAL. Propensity-matched analysis was performed for survival analysis.

RESULTS

A total of 1,203 patients with CCAL were included. The median overall survival (OS) for all patients was 19.0 months (95% CI 16.0-22.0 months). Data for 1-, 3-, and 5-year OS were 58.7, 37.3, and 27.7%, respectively. Log-rank analysis showed that the prognoses of CCAL patients were better than those with non-CCAL adenocarcinoma after propensity-matched analysis (P<0.001). Cancer-directed surgery significantly improved median OS by almost 40 months (45.0 vs 5.0 months; P<0.01). Radiotherapy after surgery prolonged survival compared with patients who only received surgery (37.0 vs 17.0 months; P<0.01). Multivariate Cox analysis showed that older age (>65 years), larger lesions, and lymph node and distant metastases were independent prognostic factors for worse survival, while cancer-directed surgery was an independent protective factor. Five independent prognostic factors were identified and entered into the nomogram. The concordance index of the nomogram for predicting survival was 0.72 (95% CI 0.69-0.74). The calibration curves for the probability of 3-, 5-, and 10-year OS showed optimal agreement between nomogram prediction and actual observation.

CONCLUSION

CCAL is a rare pathology, and older age, larger lesions, metastases, and cancer-directed surgery were associated with prognosis. A prognostic nomogram was established to provide individual prediction of OS.

Analysis of mutational and clinicopathologic characteristics of lung adenocarcinoma with clear cell component

Introduction

Lung adenocarcinoma with clear cell component is extremely rare and the cases reported in literature remain scarce. The biological behaviors, clinicopathologic characteristics, mutational status and prognosis of lung adenocarcinoma with clear cell component are still uncertain.

Methods

Thirty-eight lung adenocarcinomas with clear cell component and 1659 lung adenocarcinomas were subjected to the study. All the corresponding clinicopathologic data, the distributions of relapse-free survival (RFS) and overall survival (OS), and the status of gene mutations were investigated.

Results

Of 1697 adenocarcinomas, 38 (2.2%) had clear cell component. Fifty percent of adenocarcinomas with clear cell component (11/22) harbored EGFR mutation, 41 percent (9/22) harbored KRAS mutation and 5 percent (1/22) harbored AKT1 mutation. Univariable analysis revealed that sex, age, tumor stage, tumor size, nodal stage and pathology were all significant predictors of RFS and OS while the tumor size and nodal stage were still significant predictors in multivariable analysis. There were significantly differences in RFS and OS for lung adenocarcinomas with clear cell component compared with those lung adenocarcinomas.

Conclusions

Lung adenocarcinoma with clear cell component is a rare, malignant tumor with poor prognosis and displays more frequent EGFR and KRAS mutations.

Primary clear cell carcinoma of the trachea: A CARE-compliant case report

RATIONALE

Primary clear cell carcinoma of the lung is a rare condition, and presentation as an endotracheal lesion is even more unusual. In this report, we present a patient with clear cell carcinoma occurring in the trachea, which obstructed the tracheal lumen and lead to the respiratory distress.

PATIENT CONCERNS

A 60-year old female patient was admitted due to a 6-month history of dyspnea with worsening symptoms for 1 month. Chest CT scan revealed a smooth nodular shadow with homogeneous density on the wall of upper trachea.

DIAGNOSIS

Bronchoscopy therapy and surgical removal of the tumor were performed. The histopathological diagnosis revealed clear cell carcinoma.

INTERVENTION

Surgical removal of the clear cell carcinoma was performed.

OUTCOMES

The patient recovered well after the surgery and is now being followed-up after hospital discharge.

LESSONS

Bronchoscopy is an essential tool for diagnosis of tracheal clear cell carcinoma. Surgical removal should be performed if possible.

Clear cell adenocarcinoma with endobronchial polypoid growth

Clear cell adenocarcinoma of the lung is extremely rare. On radiography, a 45-year-old female with fever was found to have an abnormal shadow in the left lower lung field. Bronchoscopy revealed a polypoid tumor in the left bronchus. On biopsy, the tumor was determined to be adenocarcinoma. Preoperative examination found no tumors outside of the lung. The patient underwent left lower lobectomy with bronchial wedge resection. The tumor had completely obstructed and dilated the left lower bronchus, but had not invaded the tissue outside the bronchial wall. Microscopically, the cytoplasm of the tumor cells contained abundant glycogen, and the tumor had solid and glandular structures. The tumor was diagnosed as clear cell adenocarcinoma of the lung.