case_images: PMC10764176_01
case_images: Images during the course of the disease.. MRI showing preoperative findings (A), third day after surgery (B), and two weeks after surgery (C). A 14-Gy dose was delivered to the tumor margin at the 40% isodose (yellow line) for a lesion from the cavernous sinus to the left middle cranial fossa (D left panel) and a 23-Gy dose was delivered to the tumor margin at the 40% isodose (yellow line) for a lesion from the right side of the clivus to the right middle cranial fossa (D right panel). Two months after irradiation by a gamma knife (E). Fludeoxyglucose-18 positron emission tomography three months after surgery (F) and 5.5 months after surgery (G).
case_images: cureus-0016-00000051605-i01.jpg
case_images: PMC10764176_01_cureus-0016-00000051605-i01.jpg
case_images: FIG1
case_images: MRI showed neoplastic lesions involving the clivus, sphenoid sinus, anterior ethmoid sinus, sella region, bilateral cavernous sinuses, and right internal and external pterygoid muscles (Figure 1A). Postoperatively, the residual tumor in the right cavernous sinus increased rapidly and extended into the middle cranial fossa, compressing the right temporal lobe (Figures 1B, 1C). A lesion (planning target volume (PTV) of 236.7 mL) from the cavernous sinus to the left middle cranial fossa was irradiated with a marginal dose of 14.0 Gy (central dose of 35 Gy) in two fractions (equivalent to a marginal dose of 21.4 Gy in terms of a single fraction) (Figure 1D left). A single fraction of 23.0 Gy marginal dose (57.5 Gy central dose) was given to a lesion (PTV of 123.9 mL) in the right middle cranial fossa from the right side of the clivus (Figure 1D right). The high-dose irradiation resulted in marked shrinkage of the residual tumor and improvement of symptoms (Figure 1E). However, a whole-body examination with fludeoxyglucose-18 positron emission tomography (FDG-PET) revealed abnormal accumulation in cervical lymph nodes and Lubyer's lymph nodes outside the gamma knife irradiation field (Figure 1F). Subsequent FDG-PET showed that the abnormal accumulation in the additionally irradiated cervical lymph nodes had disappeared, but numerous abnormal accumulation images were observed in the lungs and mediastinal lymph nodes (Figure 1G), indicating systemic metastasis.
case_images: Histopathology findings.. Hematoxylin and eosin staining at 100x (A), 200x (B), and immunostaining (all 200x) for cytokeratin (AE1/AE3) (C), Ki-67 (D), brachyury (E), and INI1 (SMARCB1) (F).
case_images: cureus-0016-00000051605-i02.jpg
case_images: PMC10764176_01_cureus-0016-00000051605-i02.jpg
case_images: FIG2
case_images: A small number of components with mild cellular atypia with mucus matrix inclusions were also observed (Figures 2A, 2B). Immunostaining revealed that these atypical cells were diffusely positive for cytokeratin (AE1/AE3), and the Ki-67 labeling index was approximately 80%, suggesting malignancy (Figures 2C, 2D). Additionally, the tumor cells manifested diffuse positivity for brachyury (Figure 2E), a marker for chordoma, and loss of expression of INI1 (SMARCB1) (Figure 2F).