PMC9479527_01
(a-c) Gadolinium-enhanced magnetic resonance imaging of the brain at the initial visit. Two enhanced lesions are apparent in the right cerebellar hemisphere (31 x 19-mm solid component with 24 x 14-mm cystic part; 10 x 10-mm cystic tumor, arrows), one in the right cerebellar peduncle (22 x 18 mm, arrowhead) (a and b), and one in the right parietal lobe (5 x 4 mm, arrow) (c). (d) Computed tomography of the lung at the initial visit. A mass lesion is seen in the inferior lobe of the left lung.
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F1
Contrast-enhanced magnetic resonance imaging (MRI) demonstrated multiple tumors in the right cerebellar hemisphere, right cerebellar peduncle, and right parietal lobe [Figures 1a-c]. Computed tomography (CT) of the chest revealed a mass lesion in the inferior lobe of the left lung [Figure 1d].
Positron emission tomography (PET) of the brain and lung. (a and b) Images of brain PETs. Neither 18F-fluorodeoxyglucose (FDG)-PET (a) nor 11C-methionine-PET (b) shows significant uptake in the areas identified on gadolinium-enhanced magnetic resonance imaging [Figure 1] compared to surrounding normal brain tissue. (c) Image of lung FDG-PET. A high-uptake lesion is seen in the inferior lobe of the left lung.
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F2
Both FDG- and MET-PET demonstrated no significant accumulation in the brain lesions [Figures 2a and b], while FDG-PET showed high uptake in the lung lesion [Figure 2c].
Histopathological examinations of the lung and cerebellar lesions. (a and b) Acinar and cribriform patterns of tumor cells with increased chromatin and some mucin are invading the lung, showing moderately differentiated adenocarcinoma. Bar = 100 mum (a), Bar = 50 mum (b). (c) Columnar mucinous cells containing moderate cytological atypia and clear cytoplasm are forming a lepidic pattern in a mucin-rich background. The diagnosis is corresponding to the metastasis of lung adenocarcinoma. Bar = 100 mum.
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F3
No gene mutation for molecular-targeted therapy was identified as of this point [Figures 3a and b]. However, more mucus-rich components were observed in the cerebellar lesions [Figure 3c].
Gadolinium-enhanced magnetic resonance imaging of the brain after treatment. (a and b) The two cerebellar lesions are resected, and fractionated stereotactic radiosurgery (SRS) is administered to the lesions in the right cerebellar peduncle and right parietal lobe. No evidence of recurrence is demonstrated in the right cerebellar hemisphere (arrows). The lesion in the right cerebellar peduncle shows slight shrinkage 3 months after the completion of SRS (arrowhead) (a). The lesion in the right parietal lobe is stable (dashed arrow) (b). (c) The lesion in the right cerebellar peduncle shows marked shrinkage 4 years and 5 months after the completion of SRS (arrowhead) with no recurrence of the other lesions.
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F4
SRS was administered for the remaining lesions (27.5 Gy in five fractions to the lesion in the right cerebellar peduncle and 35 Gy in five fractions to the lesion in the right parietal lobe) from 1 month after surgery. Shrinkage of the remaining lesions was attained by 3 months [Figures 4a and b] and no recurrence has been observed as of 4 years and 5 months after the completion of fractionated SRS, although additional SRS has been required for new metastatic lesions [Figure 4c].