Primary intrapulmonary thymoma

Analysis of Pulmonary Function in Thymoma Subjects: A 20-Year Retrospective Cohort Study

BACKGROUND

Thymoma is the most common tumor of the anterior mediastinum. However, the correlation between thymoma stage and pulmonary function was not assessed. Our objective in this study was to describe the pulmonary function in thymoma subjects stratified with different staging systems.

METHODS

A total of 143 subjects with a diagnosis of thymoma who underwent extended thymectomy for thymoma between January 2001 and December 2019 were reviewed retrospectively. All the subjects experienced pulmonary function tests (PFTs) using Master Screen PFT system and total respiratory resistance measurement.

RESULTS

We evaluated 143 subjects with a diagnosis of thymoma; the significant differences were observed in mean values of vital capacity, inspiratory volume (IC), total lung capacity (TLC), ratio of residual volume to total lung capacity (RV/TLC), forced vital capacity, forced expiratory volume in 1 second, ratio of forced expiratory volume in 1 second to forced vital capacity, peak expiratory flow, peak inspiratory flow, maximum ventilation volume, total airway resistance, and diffusing capacity for carbon monoxide (DLCO) across upper airway obstruction classification. PFTs of subjects with varying Masaoka stages are different. RV and RV/TLC of subjects in stages III and IV were higher than those of normal level, while DLCO of subjects in stage IV was lower than the normal level, and the mean level of IC showed significant difference between stage II and stage III.

DISCUSSION

The pulmonary function patterns of thymoma subjects significantly correlate with tumor location and size rather than clinical Masaoka stage.

The spectrum of ectopic thymomas

Thymomas are rare tumors that usually manifest in the anterosuperior mediastinum. Occasionally, thymomas may also originate from ectopically dispersed thymic tissue and can arise in locations such as the neck, lung, or pleura or other locations in the thoracic cavity. The occurrence of thymomas in these ectopic locations can cause substantial diagnostic difficulty as the entity is almost never included in the differential diagnosis and its biphasic morphology can cause further complications during the diagnostic process. In this review, we summarize the clinical and pathological spectrum of ectopic thymomas and discuss the histogenesis, treatment, and prognosis of these extraordinary tumors.

Bilateral multiple intrapulmonary nodules: a puzzled and rare disease

Primary intrapulmonary spindle cell thymomas (PISCT) are rare lesions that may be mistaken for a variety of benign and malignant epithelial or mesenchymal tumors. It is thought as one subtype of primary intrapulmonary thymomas (PIT). To the best of our knowledge, no bilateral multiple primary intrapulmonary spindle thymomas and treatment had been reported in literature. We fortunately diagnosed and managed this unique case, which might provide some experience for physicians who were interested in this disease.

Differential diagnosis of primary intrapulmonary thymoma: a report of two cases

Primary intrapulmonary thymomas (PITs), which are intrapulmonary tumors without an associated mediastinal component, are very rare. The diagnosis of a PIT can be difficult. Here, we report two cases of resected PITs that were difficult to differentiate from other lung tumors. The patients, of a 62-year-old man and a 64-year-old woman, had no significant symptoms and were both referred to our hospital due to the presence of an abnormal shadow on chest computed tomography (CT). The patients underwent ¹⁸F-fluorodeoxyglucose positron emission tomography-CT (FDG-PET/CT) and subsequently tumor excision. A PIT was confirmed histopathologically in the surgical specimens from both patients. In one case, the tumor consisted of a type A thymoma without abnormal FDG uptake. In the other case, the tumor consisted of a type B2 thymoma presenting with weak FDG uptake. This report thus documents two cases of PITs with different histopathologic and FDG-PET/CT findings. Thoracoscopic surgery is essential in the differential diagnosis between PITs and other lung tumors.