|Contributed by Monika Koenigsmann1, Günther Jautzke3, Matthias Unger4, Agota Théallier-Janko1, Thomas Wiegel2, Gisela Stoltenburg-Didinger1|
| 1 Dept. of Neuropathology and 2 Dept. of Radiotherapy, Free University Berlin, Germany
3 Dept. of Pathology, St.Gertrauden Hospital, Berlin, Germany
4 Dept. of Pathology, Martin-Luther Hospital, Berlin, Germany
|Published on line in June 2002|
CLINICAL HISTORY, RADIOLOGY AND MICROSCOPIC DESCRIPTION:
In 1988 a 57 year-old male patient began having symptoms of fluctuating headaches and lack of concentration. In early 1990 he noticed a deviation of his tongue towards the right side as well as double vision, vertigo and an increase of his headaches. A cranial CT scan revealed a hyperdense mass in the area of the foramen magnum (Fig. 1). Upon surgery the tumor was completely removed.
On H&E staining the tumor showed high cellularity, with isomorphic tumor cells and partial arrangement in nests (Fig. 2). Cells were medium-sized, round-to-oval with rather isomorphic nuclei, sometimes with prominent nucleoli (Fig. 3). Intra- and extracellular brownish pigment could be distinguished (Fig. 3). Mitoses were rare (Fig. 4). Immunohistochemistry was positive for S-100 and vimentin as well as HMB 45 (Fig. 5). Electron microscopy showed both highly differentiated and less mature melanosomes (Fig. 6), but no desmosomes.
Eight years later, the patient again noticed double vision, vertigo, and also diminished physical activity. Seven months later, in December 1998, a sudden deterioration of his general health occurred with right abdominal pain and recurrent herpes virus infections. Dexamethasone alleviated both the headache and the abdominal pain. A cranial CT scan this time showed a tumor mass in both the region of the previous operation and in the left cerebellar hemisphere (Fig. 7). An abdominal CT was highly suspicious for disseminated liver metastases.
Liver biopsy revealed infiltation by a solid tumor (Fig. 8) with medium-sized cells with brown granulated pigment (Fig. 9). The tumor cells had round or oval nuclei, mild pleomorphism and prominent nucleoli. Immunohistochemistry was positive for HMB 45 (Fig. 10) and tyrosinase (not shown). A distinction from regular hepatocytes was achieved by the HEP antibody (Fig. 11). A MIB-1 immunostain revealed only scattered proliferating cells (Fig. 12). Percutaneous irradiation of the neurocranium at a total dose of 30 Gy using 6 MeV-photons was performed. Systemic treatment was intended with cisplatinum. However, a further dramatic deterioration of the patient's general state with frequent generalized seizures occurred a few days after the end of radiotherapy. Therefore, the patient did not receive any chemotherapy. Instead, he died two weeks later in a state of cerebral coma. Permission for autopsy was not obtained.