Pituicytoma: Four cases with unusual imaging features and a literature review.

OBJECTIVE: Pituicytomas (PTs) are rare and benign neoplasms. The variable imaging and clinical features of PTs, which overlap with other sellar pathologies, can make preoperative diagnosis challenging. In the interest of a more comprehensive understanding of the diagnostic aspects of PTs, it is necessary to report and synthesize the variable imaging and clinical features of PTs. METHODS: We retrospectively included and analysed four pathologically proven PTs with unusual imaging and/or clinical features. Additionally, we reviewed the literature on PT between 2007 and 2019 in the PubMed database to provide context for the individual patient data described herein. RESULTS: Our series included three female and one male adult patient (mean age: 44.75, age range: 20-56 y). Based on clinical symptoms, we noticed that case 1 had Cushing's syndrome, case 2 had increased prolactin, case 3 had extremity enlargement but with a normal level of human growth factor, and case 4 presented with tinnitus and dizziness. On radiograph, inconsistent with the main imaging findings of PTs in the literature, there was one case in the pituitary anterior lobe, three cases with hypointensity on T2-weighted images, two patients with reduced homogeneous contrast enhancement, and one case demonstrating invasion potential. In addition, one of our patients underwent PET-CT examination, and the lesion had a slight increase in glucose uptake and no significant decrease in ammonia uptake. Postoperative follow-up monitoring revealed no tumour recurrence. CONCLUSION: Our cases highlight the unusual imaging manifestations of PTs. Recognizing these imaging features plays an important role in the preoperative diagnosis, treatment, and postsurgery monitoring of PTs.