Gamma Knife Radiosurgery: An Adjuvant Therapy for Primary Sellar Paraganglioma.

Sellar paraganglioma (SP) is a rare benign tumor, usually treated by surgery. SPs are lobulated, firm, adherent, and highly vascular, allowing mostly partial resection. We present the case of a 52-year-old man diagnosed with primary SP, treated with a transcranial-transsphenoidal (TC-TS) surgical approach, followed by adjuvant Gamma Knife stereotactic radiosurgery (GKSR). The tumor has an extra-pituitary origin, with a sellar-suprasellar, right cavernous sinus extension that encroached the bilateral optic nerve and anterior cerebral artery. Histopathology confirmed SP with a Zellballen pattern. Despite postoperative tumor growth observed at four and 10 months, a stable residual tumor was noted at a follow-up two years after GKSR. SP is diagnosed mainly in middle age or in adolescent males. The TC-TS approach offers a bidirectional view that allows greater resection by minimizing blind spots, thus reducing complications. Similar to the paragangliomas of other sites, the efficacy of GKSR was observed for primary SP. SP is a rare differential diagnosis of pituitary diseases; however, it should be considered. After surgical resection of primary SP, GKSR is observed as an effective adjuvant therapy.

Spinal intradural solitary fibrous tumor/ hemangiopericytoma with intramedullary invasion mimicking a hemangioblastoma.

Background: Solitary fibrous tumor/hemangiopericytomas (SFT/HPCs) are rare mesenchymal tumors of nonmeningothelial origin that comprises <1% of all central nervous system tumors. Case Description: A 45-year-old male presented with sleep apnea (apnea-hypopnea index was 17.1 events/hour) and dysesthesias of the right upper and lower extremities. The magnetic resonance demonstrated a heterogeneous intradural extra-axial C1 mass with syringobulbia and syringomyelia. The right vertebral angiography revealed a hypervascular mass (i.e., intense tumor staining). With the preoperative diagnosis of a spinal hemangioblastoma, the patient underwent tumor removal. However, intraoperative findings demonstrated that the ventral component of the tumor was intramedullary without a dural attachment. Further, the histological diagnosis was consistent with SFT/HPC (HPC phenotype). The postoperative course was uneventful, and the patient's symptoms and the syrinxes spontaneously regressed. Conclusion: A 45-year-old male presented a rare spinal intradural lesion at C1 appeared to be a spinal hemangioblastoma, but proved to be SFT/HPC (HPC phenotype) with intramedullary invasion.

Solitary Fibrous Tumor or Hemangiopericytoma of the Sella in an Older Patient Treated with Partial Removal Followed by Fractionated Gamma Knife Radiosurgery.

Solitary fibrous tumor (SFT) or hemangiopericytoma (HPC) is a rare fibroblastic tumor of mesenchymal origin. SFT or HPC comprises <1% of all primary central nervous system tumors. SFT or HPC of the sellar or suprasellar region is even more unusual. We herein report a sellar SFT or HPC in an octogenarian who achieved favorable progress with partial removal followed by fractionated gamma knife radiosurgery. An 87-year-old woman presented with occasional headache and visual field defects. A rapidly growing tumor of the sella turcica was diagnosed. The patient underwent endoscopic transnasal transsphenoidal surgery; however, only partial resection of the tumor was possible, as it was fibrous and hard with increased vascularity. A histological examination confirmed the tumor to be grade II SFT or HPC. Two months after the resection, the residual tumor grew rapidly. Given the patient's advanced age, re-surgery was not the preferred option; thus, fractionated gamma knife radiosurgery (marginal dose, 30 Gy in five fractions) was performed. MRI and visual field examination performed 3 months after irradiation revealed tumor shrinkage and improvement in the visual field, respectively. One year and three months after irradiation, the tumor continued to shrink and her visual field had improved. Taking age into consideration, partial resection with fractionated gamma knife radiosurgery was the more appropriate choice for both local tumor control and the safety of the optic apparatus.

Histopathological variation in the demyelinating sentinel lesion of primary central nervous system lymphoma.

BACKGROUND: Primary central nervous system lymphoma (PCNSL) is one of the least common malignant brain tumors. It is usually diagnosed initially as diffuse large B cell lymphoma (DLBCL). In rare cases, however, a demyelinating lesion referred to as a "sentinel lesion" precedes the actual diagnosis, which usually depicts two distinct patterns of inflammatory cells during histological analysis. This case report describes a unique histological finding and describes the recognized variations in sentinel lesion histopathology. CASE DESCRIPTION: A 78-year-old female patient was found to have multiple white matter lesions of various degrees of enhancement on post-contrast T1-weighted magnetic resonance imaging. A stereotactic biopsy of a heterogeneous lesion in the left occipital lobe was performed, which revealed demyelination along with lymphocytic infiltration, reactive astrocytosis, abundant T cells, and foamy macrophages. There was no evidence of monoclonality, rapid regression of all lesions occurred, and the patient was thus treated for tumefactive demyelination. Three months later, all of the residual lesions had enlarged and were homogeneously enhancing. An endoscopic-guided biopsy of the right periventricular lesion showed diffuse atypical lymphoid cells. CONCLUSION: The sentinel lesion of PCNSL expresses a variable histological pattern of inflammatory cells. This case demonstrates a unique and rare picture of mixed perivascular and parenchymal infiltration of inflammatory cells, highlighting the importance of repeated biopsies and/or radiological examinations to obtain an accurate diagnosis.