Recurrent Primary Intrasellar Paraganglioma

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.

Case Report: Paraganglioma in the sellar region: longitudinal observation and surgical outcome

Background

Paraganglioma in the sellar region is an extremely rare entity, with a limited number of cases reported in the literature. Due to the paucity of clinical evidence, the diagnosis and treatment of paragangliomas in the sellar region remain challenging. Herein, we reported a case of sellar paraganglioma with parasellar and suprasellar extension. Particularly, the dynamic evolution of this benign tumor within a 7-year longitudinal observation was presented. Additionally, the relevant literature regarding sellar paraganglioma was comprehensively reviewed.

Case description

A 70-year-old woman presented with progressive visual deterioration and headache. Brain magnetic resonance imaging demonstrated a mass in the sellar region with parasellar and suprasellar extension. The patient refused surgical treatment. Seven years later, brain magnetic resonance imaging showed the lesion significantly progressed. Neurological examination revealed bilateral tubular contraction of visual fields. Laboratory examinations showed endocrine hormone levels were normal. Surgical decompression was performed via a subfrontal approach, and subtotal resection was achieved. Histopathological examination confirmed a diagnosis of paraganglioma. Postoperatively, she developed hydrocephalus, and ventriculoperitoneal shunting was performed. Eight months later, cranial CT showed no recurrence of the residual tumor, and the hydrocephalus had been relieved.

Conclusion

Paraganglioma occurring in the sellar region is rare, and the preoperative differential diagnosis is difficult. Owing to the infiltration to the cavernous sinus and internal carotid, complete surgical resection is usually impracticable. There has been no consensus regarding postoperative adjuvant radiochemotherapy for the tumor residue. In-situ recurrence and metastasis have been reported in the literature, and close follow-up is warranted.

Case Report: Malignant Primary Sellar Paraganglioma With Unusual Genetic and Imaging Features

BACKGROUND

Paraganglioma occurs rarely in the sellar/parasellar region. Here, we report a patient with malignant paraganglioma with primary sellar location with unusual genetic and imaging features.

CASE PRESENTATION

A 31-year-old male presented with mild hypertension, headache, nausea, and vomiting. A sellar/parasellar tumor mass was revealed by magnetic resonance imaging (MRI), while an endocrine work-up found partial hypopituitarism, suggesting that it was a non-functioning pituitary tumor. Antihypertensive therapy and hormone replacement were initiated. Tumor reduction was achieved with transsphenoidal neurosurgery. However, histological diagnosis was not possible due to extensive tissue necrosis. After 4 years of stable disease, the residual tumor showed re-growth requiring gamma knife radiosurgery. Four years after the radiosurgery, MRI showed a significant tumor progression leading to a second neurosurgery. This time, pathological and immunohistochemical findings revealed paraganglioma. Plasma levels of metanephrine and normetanephrine were normal. A gene sequencing panel performed on DNA extracted from blood excluded germline mutations in 17 susceptibility genes. The patient developed new tumor masses in the neck, and the third surgery was performed. Immunohistochemistry demonstrated lack of ATRX (alpha thalassemia/mental retardation syndrome X-linked) protein in tumor cells, indicating an ATRX gene mutation. Molecular genetic analysis performed on tumor DNA revealed a combination of ATRX and TP53 gene abnormalities; this was not previously reported in paraganglioma. MRI and 68Ga-DOTANOC PET/CT revealed the full extent of the disease. Therapy with somatostatin LAR and 177Lu-DOTATATE Peptide Receptor Radionuclide Therapy (PRRT) was initiated.

CONCLUSION

Although rare, paraganglioma should be considered in the differential diagnosis of sellar/parasellar tumor lesions, even in the absence of typical imaging features. ATRX gene mutation in paraganglioma is an early predictor of malignant behavior and a potential novel therapeutic marker when pharmacological therapy targeting mutated ATRX becomes available.