CSF analysis showed raised protein with oligoclonal bands (also in serum) and Immunoblot confirmed positivity for anti-Ma2 antibodies, also present in serum.

Right medial temporal brain biopsy revealed a perivascular, poleoclastic T-cell mediated inflammatory process without evidence of malignancy.  The patient was diagnosed with anti-Ma2-associated encephalitis, frequently associated with testicular germ cell neoplasia in men.

Testicular ultrasound showed foci of macrocalcification in the right testis. A right orchiectomy was undertaken.  Pathological analysis confirmed the presence of a classic seminoma along with extensive intratubular germ cell neoplasia (“ITGCN”). The decision was made subsequently to remove the contralateral testis, which showed low volume ITGCN, without invasive seminoma. The patient was treated with immunosuppression and had clinical and radiological stabilization. The serum anti-Ma2 titer reduced from 1:160 to 1:40.