Endobronchial Ultrasound-guided Transbronchial Needle Aspiration in the Diagnosis of Breast Cancer Thoracic Metastases and Detection of Receptor Discordance

EBUS-TBNA in Extrathoracic Malignancies: Diagnostic and Prognostic Implications

PURPOSE

In patients with extrathoracic malignancies (EM) the role of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for the assessment of abnormal mediastinal lymph nodes (MLN) is controversial. The aim of this study was to assess the diagnostic yield and prognostic significance of EBUS-TBNA in these patients.

METHODS

Retrospective analysis of patients with EM and abnormal MLN detected by Computed Tomography (CT) and/or Positron Emission Tomography (PET).

RESULTS

A total of 161 patients with EM and abnormal MLN were included (93 males, 58%). The most common EM was melanoma (19%) and gastrointestinal cancer (17%). Assessed lymph nodes were mediastinal in 70% of cases and hilar in 30%. The most frequently sampled lymph nodes were subcarinal (45%) and lower right paratracheal (21%). Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of EBUS-TBNA for the diagnosis of malignancy were 88%, 100%, 100% and 87%, respectively. These values were similar regardless the type of EM except for head and neck tumors where the NPV was particularly low (67%). The diagnosis of neoplastic involvement by EBUS-TBNA implied a worse prognosis in terms of overall survival (p < 0.02) and cancer-specific survival (p < 0.001).

CONCLUSIONS

In patients with EM and abnormal MLN, EBUS-TBNA has a high diagnostic yield. However, the NPV decrease in patients with head and neck tumors. Neoplastic MLN detected by EBUS-TBNA has prognostic implications in these patients.

An ectopic thymoma arising in the middle mediastinum that was difficult to distinguish from a lymph node metastasis

BACKGROUND

Ectopic thymomas often occur in the upper mediastinum; however, they rarely arise in the middle mediastinum, especially on the dorsal side of the innominate vein and superior vena cava in the peribronchial region.

CASE PRESENTATION

Six years prior, a 27-year-old female presented to our department and was diagnosed with locally advanced left breast cancer. First, we administered chemotherapy including an anti-human epidermal growth factor receptor 2 antibody. The size of the tumor was markedly reduced, and a radical operation involving mastectomy and axillary lymph node dissection was then performed. The patient underwent radiotherapy after the mastectomy, followed by trastuzumab therapy; she continued to receive endocrine therapy thereafter. She underwent computed tomography once a year after the surgery, and a nodule in the middle mediastinum on the dorsal side of the innominate vein and superior vena cava in the parabronchial region was detected at 4 years. We speculated that the nodule was a solitary mediastinal lymph node metastasis from her breast cancer; therefore, we performed thoracoscopic resection of the tumor. We diagnosed the tumor as a thymoma. Currently, the patient visits our hospital to receive continuous hormone therapy for her breast cancer, and the latest computed tomography scan demonstrated no metastases from or recurrence of her breast cancer or thymoma.

CONCLUSIONS

We report a case of ectopic thymoma in the middle mediastinum. The tumor, which was detected during systemic therapy for locally advanced breast cancer, was located on the dorsal side of the innominate vein and superior vena cava in the parabronchial region and was indistinguishable from a lymph node metastasis from breast cancer.

Clinical Implications of Noncoding Indels in the Surfactant-Encoding Genes in Lung Cancer

Lung cancer arises from the accumulation of genetic mutations, usually in exons. A recent study identified indel mutations in the noncoding region of surfactant-encoding genes in lung adenocarcinoma cases. In this study, we recruited 94 patients with 113 lung cancers (88 adenocarcinomas, 16 squamous cell carcinomas, and nine other histologies) who had undergone surgery in our department. A cancer panel was designed in-house for analyzing the noncoding regions, and targeted sequencing was performed. Indels in the noncoding region of surfactant-encoding genes were identified in 29/113 (25.7%) cases and represent the precise cell of origin for the lung cancer, irrespective of histological type and/or disease stage. In clinical practice, these indels may be used as clonal markers in patients with multiple cancers and to determine the origin of cancer of unknown primary site.