['With the development and refinement of guidance modalities for percutaneous biopsies, many investigators have reported studies supporting the role of guided core needle biopsy in the diagnosis of mediastinal lymphoma. The aims of this report are to evaluate the efficacy of findings at core needle biopsy of mediastinal masses on patient care and define the key determinants of clinical success.', 'Fluoroscopy-guided (in 75 patients) and computed tomography-guided (in 8 patients) core needle biopsies were performed in 83 patients with mediastinal lymphoma: all but one of the patients were at first diagnosis. All the biopsies were performed using a Menghini needle (from 1.2 mm to 1.8 mm). In the vast majority of cases the 1.8 mm gauge was employed.', 'The overall sensitivity for the diagnosis of lymphoma was 81% (67/83 cases). In the remaining 16 patients the lymphoma diagnosis was reached either by mediastinoscopy (11 cases) or anterior mediastinotomy (3 cases) or core needle biopsy of the lung (1 case); one patient was treated directly after the needle biopsy had been unsuccessful because he needed rapid therapy. In 77/82 (93%) patients it was possible to assess the specific histotype. There was no operative mortality; all the biopsies were performed on an outpatient basis.'] Is core needle biopsy effective in the initial diagnosis of mediastinal lymphoma?