A rare case of pituitary TSH secreting microadenoma (TSHoma) complicated with sellar primitive persistent trigeminal artery; an operative implication and radiologic emphasis

Abstract Background Scientific literature has shown rareness of primitive persistent trigeminal artery (PPTA), with very few co-existences with pituitary adenomas and none being TSH secreting. Prior works did not provide enough insight on pre-operative required imaging set and intra-operative preemptive actions that skull base surgeons should be aware of. Clinical presentation Authors describe a case of TSH secreting adenoma with PPTA coursing through the sella turcica and supero-lateral to tumor; recognized in pre-operative angiograms. Patient was a 43-year old woman with clinical presentation of hyperthyroidism (agitation and hair loss) which was recognized to be central (T3: ↑3.2 nmol/L, T4: ↑18.7 μg/dL, and TSH: 3.02 μUI/dL). A flow void arterial structure was suspected in conventional anatomic MRI of sellar area and confirmed with angiographic modalities. A full set of angio-imaging modalities were utilized for best pre-operational preparation and comparison. Endoscopic transsphenoidal microsurgery was performed with conventional approach and guided by neuronavigational system. Total resection of the tumor was achieved with conservation of original circulation. Conclusion Use of imaging techniques before operation and neuronavigational modalities during surgery are preventive strategies. Void signal on anatomic MRI is an early flag to suspect vascular anomalies and variations. We believe that CT angiogram with augmented 3D reconstruction of both bony and vascular components of skull base can be superior surrogate of digital subtraction angiography (DSA). A surgeon trying to approach through the delicate anatomy of skull base should be aware of the possible variants and seek complementary modalities in suspicious cases.