In their recent article, Mathew et al report six
cases of Ma2-associated encephalitis with microscopic neoplasms of the
testis found only after orchiectomy. [1] We encountered a patient with
atypical Parkinsonism and massive rigidity due to occult testicular cancer
whose case adds to this rare condition. [2]
The
66-year-old man developed disorientation, psychomotor agitation, and
fever. Over three months, he developed an akinetic-rigid syndrome, mask-
like facies, bilateral ptosis, slow pupillary response, primitive
reflexes, and absent leg reflexes. He had a low-grade fever, tachycardia,
and profuse sweating.
Positive anti-Ma2 antibodies together with the compatible
neurological and MRI findings proved a paraneoplastic origin. Endoscopy,
FDG-PET, repeated body CT, and bone marrow biopsy revealed no neoplastic
changes. Tumor markers AFP and beta-HCG were normal. Testicular ultrasound
revealed homogeneous echo pattern, no atrophy, microcalcifications, or
masses suspicious for malignancy.
At the time of presentation in 2001, all previously reported
cases with anti-Ma2 encephalitis had testicular neoplasms. [3] Because
of life-threatening neurological deterioration, the patient’s wife
consented to bilateral orchiectomy. In line with other reports of
improvement after tumor resection in Ma2-encephalitis,[4]symptoms
improved including spontaneous eye opening, increasing alertness and
communication. The rigidity of all extremities was markedly reduced and
most primitive reflexes disappeared. The patient had prolonged
stabilization but died from pneumonia 18 months later.
The original pathological evaluation was negative for testicular
malignancies but review using placental-like alkaline phosphatase (PLAP)-
stained slides verified multiple bilateral microscopic intratubular germ-
cell neoplasia.
According to Mathew et al, our patient fulfilled only three of the
five criteria proposed for orchiectomy decision: 1) anti-Ma2 antibodies
together with clinical features compatible with Ma2-encephalitis; 2) life
-threatening deterioration of the neurological deficits; 3) absence of
other tumors. The patient failed to meet the criteria 4) age <50 years
and 5) testicular abnormalities.
Mathew et al underscore the high tumor-
specificity of the well-characterized anti-Ma2 antibodies. Secondly, even
in patients without a history of cryptorchidism, atrophy, testicular
enlargement, or microcalcifications, Ma2 antibodies together with the
neurological symptoms might--in exceptional cases--prompt consideration of
orchiectomy. Thirdly, the threshold of age of 50 years should be
reconsidered in view of our patient.
References
1. Mathew RM, Vandenberghe R, Garcia-Merino A et al. Orchiectomy for
suspected microscopic tumor in patients with anti-Ma2-associated
encephalitis. Neurology 2007;68:900-905.
2. Prüss H, Voltz R, Flath B et al. Anti-Ta associated paraneoplastic
encephalitis with occult testicular intratubular germ-cell neoplasia. JNNP 2007;78:651-2.
3. Voltz R, Gultekin SH, Rosenfeld MR, et al. Serologic marker of
paraneoplastic limbic and brainstem encephalitis in patients with
testicular cancer. NEJM 1999;340:1788-95.
4. Dalmau J, Graus F, Villarejo A, et al. Clinical analysis of anti-Ma2-associated encephalitis. Brain 2004;127:1831-1844.
Disclosure: The authors report no conflicts of interest.