Mediastinoscopy: a critical evaluation of 220 cases

CT-guided fine needle aspiration biopsy in the diagnosis of mediastinal tuberculosis

Twenty-two patients with mediastinal tuberculosis were reviewed. The most common symptoms were chest pain, cough, fever, and weight loss. Results of the physical examination were unremarkable. The chest radiographs of all 22 patients showed abnormal mediastinum with no evidence of extramediastinal disease. Most (62%) had right-sided paratracheal lymphadenopathy. Mantoux skin test was positive (> 15 mm) in all patients, whereas sputum smears and cultures for acid-fast bacilli were negative. Computed tomographic (CT) guided fine needle aspiration biopsies (FNAB) were performed in 12 patients using 22- to 25-gauge needles. Ten patients had fiberoptic bronchoscopic (FOB) examination with brushings and biopsies. Mediastinoscopy (n = 8) or thoracotomy (n = 6) was performed in patients where either FNAB or FOB was not diagnostic or where lymphoma was suspected clinically. The rates of true-positive diagnoses were 20%, 66%, 75%, and 100% for FOB, FNAB, mediastinoscopy, and thoracotomy, respectively. The rate of false-negative for FNAB was 34%. Only one patient developed nonsignificant pneumothorax after FNAB. These findings suggest that CT-guided FNAB is a useful and safe procedure and should be considered in the initial evaluation of patients suspected of having mediastinal tuberculosis.

Thoracic lymphadenopathy in Asians resident in the United Kingdom: role of mediastinoscopy in initial diagnosis

Although the incidence of superficial glandular tuberculosis is high in Asian immigrants, a clinical diagnosis without biopsy has previously been shown to be inaccurate in 22% of cases. The role of diagnostic mediastinoscopy and biopsy in thoracic lymphadenopathy was therefore evaluated in 41 consecutive Asian patients. Tuberculosis was diagnosed by histological examination or culture (or both) of gland biopsy material in 24 (59%). A further 12 patients, however, also received antituberculous chemotherapy, with a response in 10 cases. If these are included, 34 (83%) were finally considered to have tuberculosis. The symptoms and ages of the patients with tuberculosis were similar to those typically seen in caucasians with sarcoidosis. Six had tuberculous bilateral hilar lymphadenopathy. In only four cases (10%) was a positive diagnosis other than tuberculosis established; in two (lymphoma and thymoma) mediastinoscopy confirmed preoperative suspicions, and saved only two more (with sarcoidosis and vascular anomaly) from unnecessary antituberculous treatment. Complications included severe haemorrhage (1) and chronic tuberculous sinus in the endoscopy tract (2). Mediastinoscopy is unlikely to change management in most patients, produces an appreciable amount of morbidity, and should be reserved for cases in which there is additional clinical doubt. Any future decline in the prevalence of tuberculosis in Asians may, however, require its further evaluation.

Tuberculosis and mediastinoscopy

Biopsy of lymph nodes at mediastinoscopy has been the method of diagnosis of tuberculosis in 14 patients; Mycobacterium tuberculosis was cultured from the nodes in nine cases, and in five there was histological evidence of the disease but cultural confirmation was lacking. All patients had radiographic abnormality of the superior mediastinum, and a frequent finding at mediastinoscopy was mediastinal fibrosis involving the fascia and lymph nodes. No cause other than tuberculosis could be demonstrated to account for the mediastinal fibrosis, and the patients made clinical recoveries in response to standard courses of antituberculosis chemotherapy. The development of superior vena caval compression was not observed.

Evaluation of 178 Mediastinoscopies

Of the 178 consecutive mediastinoscopies performed at the Istituto Nazionale per lo Studio e la Cura dei Tumori of Milan from 1967 to 1974 145 were performed for diagnostic purposes and 33 for the pre-operative evaluation of resectability in cases of proven lung carcinoma. Mediastinoscopy is a very useful procedure for obtaining a definite pathological diagnosis in indeterminate mediastinal and pulmonary lesions. In such cases, mediastinoscopy should precede any attempt at therapy, as 1/3 primary mediastinal lymph node lesions are benign and about 30% of suspected mediastinal tumors or lymphomas are actually misdiagnosed lung cancers (mainly oat-cell carcinomas). As to the role of mediastinoscopy in the assessment of lung cancer resectability, the current view is that it plays a part together with tomography and bronchoscopy in the clinical staging of this neoplasm, but it is no longer relied upon alone. It is mandatory in every case of suspected or probable mediastinal invasion and the criteria for inoperability are the following: spread to high paratracheal or contralateral nodes, direct invasion of the mediastinal fat, fixity of the neoplasm to the trachea or vertebral bodies. In such cases mediastinoscopy will prevent a useless exploratory thoracotomy.