Malignant trigeminal nerve sheath tumor and anaplastic astrocytoma collision tumor with high proliferative activity and tumor suppressor p53 expression

Abstract

Background. The synchronous development of two primary brain tumors of distinct cell of origin in close proximity or in contact with each other is extremely rare. We present the first case of collision tumor with two histological distinct tumors. Case Presentation. A 54-year-old woman presented with progressive atypical left facial pain and numbness for 8 months. MRI of the brain showed left middle cranial fossa heterogeneous mass extending into the infratemporal fossa. At surgery, a distinct but intermingled intra- and extradural tumor was demonstrated which was completely removed through left orbitozygomatic-temporal craniotomy. Histopathological examination showed that the tumor had two distinct components: malignant nerve sheath tumor of the trigeminal nerve and temporal lobe anaplastic astrocytoma. Proliferative activity and expressed tumor protein 53 (TP53) gene mutations were demonstrated in both tumors. Conclusions. We describe the first case of malignant trigeminal nerve sheath tumor (MTNST) and anaplastic astrocytoma in collision and discuss the possible hypothesis of this rare occurrence. We propose that MTNST, with TP53 mutation, have participated in the formation of anaplastic astrocytoma, or vice versa.

Figure 1

Preoperative enhanced parasagittal T1-WI MRI demonstrates extra-axial heterogeneously dumbbell-shaped enhancing tumor in the left middle fossa extending into infratemporal fossa.

Figure 2

Axial T1-WI MRI demonstrating mass effect and infiltration to the temporal lobe with vasogenic edema.

Figure 3

Coronal T1-WI MRI demonstrating middle cranial fossa tumor extending to the infratemporal region.

Figure 4

Microphotograph shows anaplastic astrocytoma with numerous mitoses (Hematoxylin & Eosin, original magnification ×20).

Figure 5

Microphotograph demonstrating significant P53 immunopositivity of anaplastic astrocytoma.

Figure 6

Ki 67 proliferative index of 10% per 10 HPF in the anaplastic astrocytoma.

Figure 7

Microphotograph shows MTNST with extensive atypia, mitosis, and necrosis (Hematoxylin & Eosin, original magnification ×20).

Figure 8

P53 immunopositivity of MTNST was apparent.

Figure 9

Ki 67 proliferative index of 10% per 10 HPF in MTNST.

Figure 10

Postoperative (24 hr) follow-up T1-WI parasagittal MRI demonstrates complete resection of tumor from the infratemporal region.

Figure 11

Postoperative (24 hr) follow-up T1-WI axial MRI demonstrates complete resection of tumor from the middle region.

Figure 12

Postoperative (8-month) follow-up T1-WI axial MRI demonstrates recurrent local tumor, likely from anaplastic astrocytoma component, and distant spread to the anterior part of corpus callosum.