|Contributed by F. Alameda, M. Natcher, MJ. Guardiola, MD 1 E. Galito, MD 1 I. Moysset, MD, S. Serrano, MD and F. F. Cruz Sanchez, MD 2|
|Depts. of 1Pathology and Neurosurgery, Hospital del Mar. Autonomous University of Barcelona; 2 Institute of Neurological Sciences, Universitat Internacional de Catalunya.|
|Published on line in April 2003|
The patient was a diabetic male in his 50s with progressive loss of sensitivity on the left side of the body and horizontal diplopia. Symptoms appeared after a right basal pneumonia one month before admission. The patient did not have a risk factor of HIV infection. The routine blood analysis was normal. A CT scan showed an expansive lesion in the pons (Fig. 1), which was considered as non-surgical. The patient was treated with corticoids. One week later, the patient showed general deterioration. The fifth and sixth right cranial nerves were affected. Ataxia and disorders in swallowing were also present. A second CT scan showed that the pontine mass had become larger. The patient died 7 days after his admission and the autopsy was limited to CNS.
The formalin-fixed brain weighed 1424 grams. The forebrain did not show any lesions. The right middle cerebellar peduncle showed a 2 cm. well defined white brownish necrotic lesion that extended to the pons and periventricular gray matter (Fig. 2).
Microscopical examination showed an inflammatory lesion composed of lymphocytes, macrophages and necrotic debris. The inflammatory process affected blood vessel walls, which showed fibrinoid necrosis. Numerous cysts and pseudo-cysts containing multiple basophilic granular ovoid structures were also seen (Fig. 3). A diagnostic immunohistochemical study was done (Fig. 4).
Brain tissue (CNST) was tested for HIV. In Fig. 5, column 1 is a DNA ladder, column 2 is a positive control for HIV pol region using nested primers, column 2 is the CNST tested for HIV-pol and column 4 is the CNST using primers for beta globin to control the integrity of the DNA in CNST tissues. This test demonstrates that the patient was HIV-negative.