This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
8/7/2019 1008 Case 2
http://slidepdf.com/reader/full/1008-case-2 1/4
C A S E O F T H E M O N T H O C T O B E R 2 0 0 8 ( C A S E 2 )
A 33-YEAR-OLD CHINESE WOMANWITH A LEFT FRONTAL
TUMOR
CASE HISTORY
A 33-year-old Chinese woman presented with intermittent slurring
of speech, dysphasia together with right upper limb and facialweakness for two months with gradual worsening of the symptoms.
Physical examination found decreased pin-prick sensation over
right C6 to C8 dermatome and impaired proprioception in right
hand. CT scan with contrast showed a well-demarcated contrast-
enhancing left frontal tumor measuring 4.5 ¥ 4.2 ¥ 3 cm with
perilesional edema and slight mass effect. Cystic changes were
observed. The tumor was close to the cortical surface but not con-
nected to the meninges (figure 1). Surgical exploration found a
non-encapsulated, well-circumscribed, vascularized tumor in the
left frontal lobe. Tumor debulking under intraoperative cerebral
function monitoring was performed. Around 95% of tumor was
removed but complete excision could not be achieved due to sig-
nificant decrease in amplitude of the brain motor evoked potentials.
The patient recovered well after the operation with complete resto-
ration of the function in the precentral and postcentral gyri as well
as Broca’s area.
PATHOLOGIC FINDINGS
Multiple pieces of soft greyish fragments altogether measuring
3 ¥ 2 ¥ 2 cm in aggregate were sent for pathological examination
in fresh state. They were used in intraoperative cytologic smear,
frozen section and subsequent histology as well as ultrastructural
examination.
Intraoperative smears showed loose aggregates of polygonal and
rhabdoid cells with eccentric nuclei and abundant cytoplasm. Intra-
cytoplasmic inclusion bodies were occasionally seen. No signifi-
cant cellular atypia or necrotic material was discerned. A glial
fibrillary background was not evident. Neither psammoma bodies,
intranuclear inclusions, nor papillary structures were found.
Histologic sections showed a malignant tumor arranged in sheets
and pseudopapillary pattern (figure 2).A distinct border was appre-
ciated between the tumor and non-tumorous glial tissue. Most
of the tumor cells displayed a rhabdoid appearance with uniform,
eccentric nuclei and eosinophilic cytoplasm. Intracytoplasmic
globules were observed in places (figure 3). Some of the tumor
cells showed a primitive appearance. Perivascular pseudorosettes
as characterized by stout cytoplasmic processes radiating towards
central hyalinized blood vessel were easily found (figure 4). No
fibrillary matrix was seen in the stroma. Stromal hyalinization and
calcifications were focally present. No palisaded necrosis was seen.
Four mitotic figures were identified per 10 high power fields.
The rhabdoid tumor cells displayed a multilineage immunohis-
tochemical profile. They were focal but strongly immunoreactive
for glial marker glial fibrillary acidic protein (GFAP) (figure 5),
diffuse and strongly positive for neural marker S100-protein
(figure 6) and focal but strongly reactive for cytokeratin markersMNF116 and Cam5.2 (figure 7). In addition, diffuse and strong
membranous and cytoplasmic dot-like pattern was appreciated
with epithelial membrane antigen (EMA) (figure 8). The tumor
cells were diffusely positive for vimentin. No neuronal differentia-
tion was demonstrated with synaptophysin and neurofilament.
There was no loss of INI-1 protein (not shown). Dual-color FISH
analysis was performed on paraffin sections with a target probe
generated from BAC clone RP11-71G19 (22q11.23), which covers
the entire SMARCB1 gene (associated with rhabdoid tumors), and
the reference probe from RP11-494O16 (22q13.33). No deletion
was discerned. The proliferation index was approximately 10%.
The tumor cells were negative for HMB-45, actin and desmin.
Ultrastructural studies showed whorls of intermediate filaments
in the cytoplasm of the rhabdoid cells (figure 9). In addition,
microvillous projections were observed on the cell surface
(figure 10). An occasional intercellular junction was identified. No