PMC9534564_01
Preoperative and postoperative magnetic resonance (MR) images and microphotograph of the tumor specimen obtained at initial tumor resection. (A) Preoperative sagittal gadolinium enhanced T1-weighted images showing homogeneously enhanced fourth ventricular mass lesion and obstructive hydrocephalus. (B) Hematoxylin-eosin staining demonstrating that the epithelioid tumor cells proliferated with high cellularity and poorly structured sheet formation. Papillary proliferation of cuboidal epithelial cells, with microvilli around vascular structures, were focally found (arrows in left panel). Necrosis (arrows in right panel) were noted. Bar = 200 mum (left panel) and 100 mum (right panel). (C and D) Postoperative MR images (C) and MR images after radiation therapy and 24 cycles of nimustine hydrochloride (D) demonstrating the residual lesion in the floor of the fourth ventricle (arrows) postoperatively and complete remission after radiation therapy and chemotherapy.
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Brain magnetic resonance (MR) imaging demonstrated a homogeneously enhanced mass lesion at the fourth ventricle, which caused local mass effect and obstructive hydrocephalus (Fig. 1A). Histological examination found that the epithelioid tumor cells had proliferated, with high cellularity and poorly structured sheet formation (Fig. 1B). Although papillary configuration was lost in most areas, papillary proliferation of cuboidal epithelial cells around vascular structures were focally found (left panel in Fig. 1B). More than five mitoses in 10 high-power fields and necrosis were also found (right panel in Fig. 1B). Postoperative gadolinium enhanced T1 weighted MR imaging showed residual lesion in the fourth ventricle floor (Fig. 1C). She tolerated the procedure well, and, two years after the operation, the residual lesion had completely disappeared (Fig. 1D).
Preoperative and postoperative sacral magnetic resonance (MR) images of the recurrent tumor in the sacral area. (A) Sacral sagittal (left) and axial (middle) gadolinium enhanced T1-weighted MR images and bone sagittal CT (right) 17 years after initial treatment, demonstrating mass lesion of the sacral canal with osteolytic changes without marginal sclerosis. (B) Sacral sagittal (left) and axial (right) T1-weighted MR images 18 months after the diagnosis of sacral lesion, demonstrating tumor enlargement and extension beyond the dura mater of the sacral canal (arrow). (C) Follow-up sacral gadolinium enhanced T1-weighted images demonstrating that postoperative residual disease (arrows) showed no growth 17 months after salvage radiation therapy.
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Sacral MR imaging demonstrated a mass lesion occupying the sacral spinal canal and osteolytic changes of the sacral canal 17 years after the initial treatment (Fig. 2A). MR imaging indicated growth of the mass lesion and extension beyond the dura mater (Fig. 2B). The residual tumor showed no growth at 17 months after re-irradiation (Fig. 2C).
Microphotograph of the specimen of the recurrent tumor. Hematoxylin-eosin staining demonstrating that atypical cells showing pleomorphism proliferated with high cellularity, poorly structured sheets of tumor cells, and blurring of the papillary pattern. Large necrotic areas were noted (left panel). Bar = 500 mum (left panel) and 100 mum (right panel).
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Histological examination of the recurrent tumor specimen found atypical cells showing pleomorphism had proliferated with high cellularity, poorly structured sheets of tumor cells, and blurring of the papillary pattern (Fig. 3). Large necrotic areas were found (left panel in Fig. 3).