an 81-year-old woman suffered from progressive gait disturbance, stumbling and fatigue over the last 2 weeks. Before admission she observed a suddenly enhancing haemiparesis of her lower left limb. in her medical history, 66 months ago, the diagnosis of a corpus uteri carcinoma (pT1c, pn0 (0/27), pMx, R0) was made followed by resection with lymphadenectomy and subsequent external fractionated radiation. sixteen months earlier, a local vaginal recurrence of this carcinoma was treated by local excision (R1) and radiation. Furthermore, 47 months earlier the patient had a vitrectomy of both eyes due to vitreous opacity. Histopathological analyses showed an abnormal lymphocytosis without prove of a lymphoma. Finally, 42 months ago a B-cell chronic lymphocytic leukaemia (B-Cll), state Binet a, was diagnosed with a marked leucocytosis of 26,900/μl in the blood. Repeated intra-vitreal administrations of Rituximab were indicated 36 months ago. The B-Cll has been classified stable upon the last clinical controls. Upon admission to the hospital the patient presented with a left haemiparesis emphasizing the lower limb (3/5), a left facial paresis, a left positive Babinski’s sign and a mild dysarthria, without any associated disorientation. after discussion in our interdisciplinary tumour board a serial stereotactic biopsy was recommended and performed under local anaesthesia using a stereotactic system (MHT stereotactic systems, Bad Krozingen, Germany) with a 1 mm probe and biopsy forceps. Postoperatively, the patient had no discernible change of her neurological status and was discharged after an uneventful recovery to a secondary care facility.