Abstract. Computed tomography (CT) is the non-invasive staging procedure of choice for assessment of metas tasis to mediastinal lymph nodes in patients with bronchial carcinoma. Cervical mediastinoscopy can provide his tologic evidence of mediastinal spread to the peritracheal, tracheobronchial and subcarinal lymph nodes. Subaortic and para-aortic nodes cannot be sampled via this route. The present study was performed to assess the staging value of the parasternal mediastinoscopy as a separate entity. Cervical and parasternal mediastinoscopy was performed in 37 patients with a proven diagnosis of non-small cell carcinoma of the left upper lobe. In 16 pa tients lymph node or tumor tissue could be biopsied via the parasternal route, in 21 patients no parasternal bi opsy was taken. Of the 16 cases with biopsies, only one was positive (6%). Histologic examination of lymph node biopsy tissue was false negative in one other patient (6%). Of the 21 patients without biopsies taken during par asternal mediastinoscopy, three (14%) had proven lymphogenic spread to the subaortic and para-aortic nodes, detected at thoracotomy. The parasternal procedure changed treatment in only one patient (3%). Diagnostic sen sitivity was 20%. It is concluded that parasternal mediastinoscopy should not be used as a routine staging proce dure in patients with left upper lobe lung cancer. [Eur J Cardio-thorac Surg (1995) 9: 655-658] Key words: Parasternal -Mediastinoscopy -Lung cancerThe value of mediastinoscopy in the preoperative assessment of bronchial carcinoma is a subject of ongoing dis cussion. Cervical mediastinoscopy should be used for stag ing in the case of a so-called positive computed tomogra phy (CT) scan (mediastinal lymph nodes of 1.5 cm diam eter or larger, or a group of nodes each 1.0 cm or larger) [4J. Histologic evidence of mediastinal metastasis is man datory in all cases of enlarged nodes on CT scan.The value of parasternal (anterior) mediastinoscopy or mediastinotomy has been discussed in only a few recent publications [1, 4, 5,8,11,14]. In many instances no dif ference is made between the staging value of the cervical and the parasternal procedure. Due to the route of lympho genic spread, the parasternal mediastinoscopy is supposed to be important in the preoperative assessment of left upper lobe tumors [3,10,15]. The benefit of cervical mediasti noscopy is limited to patients with central mediastinal in volvement. Parasternal mediastinotomy is an alternative procedure, but is apparently more invasive than mediasti noscopy. The extended cervical mediastinoscopy, as ad vocated by Ginsberg, is not practised by many surgeons [1]. In some institutes the attitude towards mediastinos copy in general, and towards parasternal mediastinoscopy in particular, appears to have changed. This is partly due to the development of improved CT imaging techniques, which show mediastinal structures with a higher defini tion than 5 or 10 years ago, In order to reassess the value of the staging of lympho genic spread of bronchial carcinoma b...