Imaging and clinical course of metastatic pituitary neuroendocrine tumors (PitNET): A single center case series

PurposeMetastatic pituitary neuroendocrine tumors (PitNET) are exceedingly rare tumors that are typically diagnosed at the time of metastasis. Given the rarity of metastatic PitNET tumors, the pattern of metastasis and imaging appearance of CNS and extra neural metastasis is under reported and poorly understood.MethodsIn this retrospective case series, we present 14 consecutive patients with pathology-confirmed metastatic PitNET tumors. We assess imaging features of primary pituitary disease at the time of diagnosis, temporal evolution of local disease, and distant metastasis on multimodality imaging. We also explore potential association of initial pathology diagnosis and time to metastasis and survival.ResultsAt the time of metastasis, nine patients had evidence of disease in the sella and three additional had evidence of disease in the cavernous sinus. The most common site of metastatic disease was the CNS (78.6%). Dural deposits were the most common brain CNS metastatic disease manifestation (81.8%). Eight patients (57.1%) demonstrated multiple metastatic disease sites, with five of them (62.5%) showing both CNS and extra CNS metastases. Osseous metastatic disease was the most common extra CNS disease site (75.0%). Median time to metastasis did not significantly differ between patients with adenoma and those with more aggressive pathologies at initial diagnosis (<i>p</i> value = .39). Similarly, median overall survival from metastasis detection was not significantly affected by pathology (<i>p</i> value = .84).ConclusionMetastatic PitNET is a rare neuroendocrine neoplasm. In the present case series, we detail temporal imaging findings of the disease at the primary site and patterns of metastasis.