case_images: PMC11813563_01
case_images: MRI images of the patient. An enhancing lesion in the left parietal lobe is observed; a large area of perilesional brain edema is also visible. A: T2-weighted image. B: T1-weighted image. C: T2-weighted-fluid-attenuated inversion recovery. D: Enhancing image. (A), (B), and (C) were taken by the local hospital two days before the patient visited the out-patient department, while the enhancing image was taken at our hospital the day before surgery.
case_images: btrt-13-23-g001.jpg
case_images: PMC11813563_01_btrt-13-23-g001.jpg
case_images: F1
case_images: Based on the radiological features observed, this prompted a differential diagnosis that included malignant glioma or tumefactive demyelination (Fig. 1).
case_images: Intraoperative microscopic image of the lesion. A: The lesion did not show activation of 5-aminolevulinic acid. B: The pathological lesion was challenging to distinguish from normal tissue visually.
case_images: btrt-13-23-g002.jpg
case_images: PMC11813563_01_btrt-13-23-g002.jpg
case_images: F2
case_images: However, the lesion exhibited no fluorescence when exposed to 5-ALA (Fig. 2A). Distinguishing the tumor from surrounding normal brain tissue was challenging, as no significant morphological differences were macroscopically visible (Fig. 2B).
case_images: H&E stain and Immunohistochemical profiles of the tumor. A: H&E staining. Foamy histiocytes with lymphocytic infiltration are observed (x100). B: Higher magnification image of H&E (x400). Higher magnification H&E imaging revealed denser cytoplasm with lymphocytic infiltration. C: Tumor is positive for CD68 (x200). D: The tumor showed negativity for BRAF V600E (x200). E: Tumor is negative for Langerin (x200). F: Tumor showed nagativity for CD1a (x200). G: Tumor is positive for ALK (D5F3) (x200). H: Tumor is equivocal for ALK-1 (x200). I: Tumor showed negativity for S-100 (x200). J: Tumor showed negativity for Cyclin D1 (x200). K: Tumor is negative for GFAP (x200). L: Ki-67 index was 5.51%, indicating a relatively low proliferative activity of the tumor cells (x200). H&E, hematoxylin and eosin; ALK, anaplastic lymphoma kinase; GFAP, glial fibrillary acidic protein.
case_images: btrt-13-23-g003.jpg
case_images: PMC11813563_01_btrt-13-23-g003.jpg
case_images: F3
case_images: Characteristic findings in XG and RDD were not observed such as touton giant cells and emperipolesis (Fig. 3A and B). Immunohistochemistry (IHC) results showed positive staining for CD68 (Fig. 3C) and ALK (D5F3) (Fig. 3G), while ALK-1 staining was equivocal (Fig. 3H). The tumor was negative for Langerin (Fig. 3E), CD1a (Fig. 3F), BRAF V600E (Fig. 3D), S100 (Fig. 3I), Cyclin D1 (Fig. 3J) and glial fibrillary acidic protein (GFAP) (Fig. 3K). The tumor showed 5% positive for Ki-67 (Fig. 3L).