THE melanomas that originate in the meninges bear a general structural resemblance to those arising elsewhere, but it is questionable whether they ever metastasise outside the central nervous system. With rare exceptions, however, they have proved fatal. Most cases have clearly been tumours infiltrating t,he brain massively, but in some there was no destruction of brain substance at all, and an attempt is made in this paper to discover whether a benign form of the condition exists. The published case material available for review is now extensive. Jutte (1939) in a critical discussion covering nearly all the earlier literature referred t o 34 definite or probable primary meningeal growths and to 3 possible ones. We see no reason to reject the latter 3 cases, but 2 of the first group, the cases described by Koelichen (1916) and by Garcin et al. (1933) seem to us insufficiently documented to merit inclusion. A fresh survey of the literature reveals 29 additional cases adequately investigated post mortem and 6 possible cases observed surgically ; we have rejected many reports because of the presence of visceral metastases or other reasons. Two further cases of primary meningeal melanoma are described here.
CASE REPORTSCase 1 I n September 1953 a 51-year-old woman first noticed numbness and parzesthesia in her left leg and right hand and stiffness of her left leg ; a year later the right foot became numb. Partial Brown-SBquard syndrome with loss of pain sensation up to T 10 and spasticity of the legs was diagnosed but myelography and other investigations failed to reveal the cause ; dextrocardia, was noted. By May 1955 she was worse and complained of headaches and dimness of vision for the first t h e , and there was marked papillcedema on the right side. The cranial nerves were unaffected and the upper limbs were normal ; the lower limbs were weak and spastic and vibration sense was now lost. Remains of the myodil previously injected were scattered in loculi in the lumbar theca and were difficult to move on tilting the patient. Neck stiffness developed and her mental condition became dull ; she was afebrile. The working diagnosis at this time was arachnoiditis of unknown Etiology. Ventriculography was carried out on 28.6.55 ; the ventricles were normal in shape but the cerebrospinal Auid pressure was high. Air would not enter the cisterna magna. Following the ventricular tap the patient became mentally clearer but she never J. PATH. BdCT.-VOL. LXXW (1957) 419
