| The patient is a 66-year-old male with a 10-day history of progressive nausea, vomiting, and orthostatic dizziness. The patient's nausea was intractable to Zofran. He presented to the ER with the above complaints and dehydration and was admitted to the neurosurgery service. A CT scan of the head was done, which showed a solid mass in the brain. The tumor was removed via craniotomy. Surgery was complicated by perioperative MI. The medical management was optimized. He was stabilized and discharged.
The patient's past medical history was significant for coronary artery disease status post CABG, diabetes mellitus, and hypertension.
LABORATORY DATA
Noncontributory.
ANCILLARY STUDIES
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CT scan of head (Figure 1:) shows a partially calcified mass lesion in the anterior aspect of the right cerebellum with shift of the fourth ventricles to the left. |
| Figure 1: |
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GROSS PATHOLOGY
Three separate specimens were received from right posterior fossa tumor (right cerebellopontine angle):
- Specimen 1
consists of one piece of tan/pink soft tissue measuring 3 x 2 x 2 mm. The entire specimen is submitted for frozen section .
- Specimen 2
consists of two fragments of calcified material measuring 5 x 5 x 2 mm in aggregate.
- Specimen 3
consists of multiple irregular fragments of tan/pink soft tissue, measuring in aggregate 3 x 3 x 0.3 cm. It is entirely submitted.
MICROSCOPIC PATHOLOGY
H&E-stained sections from Specimens 1 and 3 show a spindle cell neoplasm forming fascicles and sheets with prominent hyperchromatic nuclei, eosinophilic and/or fibrillar cytoplasm with occasional mitotic figures (Figure 2). Areas of myxoid degeneration, focal calcification, and necrosis are also noted. In addition to the spindle cell neoplasm, Specimen 3 shows another type of neoplasm composed of glial cells with prominent perivascular pseudorosette formation and benign, rounded nuclei (Figure 3). It is evident that there are two distinct neoplasms in the same location (Figure 4).
Specimen 2 shows an extensively calcified structure with numerous psammoma body-like structures. The surrounding cells in this tissue appear to be glial in nature.
Immunostaining (Specimen 3):
- GFAP:
Positive cells in the glial area, particularly around the perivascular pseudoresettes (Figure 5). Spindle cell neoplasm is also focally positive.
- S100:
Positive in both the glial and spindle cell components.
- Smooth muscle actin and Desmin:
Positive in the cells with the dense eosinophilic cytoplasm within the spindle component (Figure 6). The glial component is negative.
- Myoglobin:
Positive in few spindle cells (Figure 7).
- Ki67-MIB 1 (proliferation index):
High percentage of positivity in the spindle cell component (50-60%). The glial component is less than 5% positive.
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