[Classical low back pain and sciatica syndrome caused by a melanotic nerv sheath tumour of the first sacral root (author's transl)].

This is the description of the case of a 22 year old patient with low back pain and sciatica on the right side investigated by lumbar Dimer-X-Myelography. The result of the examination was an impression in the contrast column at the L5/S 1 level on the right. At operation an intradural tumour, plum-sized, well-defined, and blue-black in colour, was found and removed. Histologically the tumour was melanotic and of high cellular density, with spindle-shaped cells as well as giant cells, with round nuclei, considerable polymorphism, and atypical mitoses. On the basis of the operation finding, the clinical course, and the histology, the diagnosis is melanotic nerve sheath tumour of the first sacral root. For two years following operation the patient has experienced no discomfort.